More

Creating new lines from existing lines based on points lying along the lines

Creating new lines from existing lines based on points lying along the lines


I am pretty new to PostGIS and I have a problem I just can't figure how to start. I have a table of lines (id, name, the_geom) and a table of points (id, name, the_geom). Each point is located on a line and a line might have one or more points etc. The points can be located anywhere along the line, not just at vertices.

How can I create new lines from each line using points along the line given just the lines and points tables. For example, line ABCDEFG is a single line with its unique name and unique id in the lines table. How can I create new lines AB, BC, CD, DE, EF, FG such that they all have the same name as line ABCDEFG but different id, and load their new geometry into a new table of lines using PostGIS? Note that A and G are the start and end of line ABCDEFG and not actual points in the points table.

Example 1:


This is not an answer, but an attempt to explain the question better, following Chris' comment.

@Chris, the links you gave are nice but quite different from what I want to achieve. I am not trying to get the individual segments of lines based on the vertices of the lines themselves. What I am trying to achieve is to make sublines from lines based on where points from a different table intersect the lines. I think my diagram is a bit confusing, I have uploaded something better.


First you find closest line for your points (ST_Distance) , then you can use ST_LineLocatePoint(line,point) to find 0-1 values for your point on line. Group them by closest lines and create new one.

Now if i understood question right you want just draw line in "correct" order.

someting like

SELECT ST_MakeLine(g.point) as newline from ( select point ,ST_LineLocatePoint(l.lines, point) as dif -- this finds order of points from XXX , (SELECT lines from Y where id =1 ) as l WHERE ST_Within(l.lines, point) < 2 -- find all point in 2 meters from line GROUP BY line -- create group by line ORDER BY ST_LineLocatePoint(linestring, point) ASC -- this finds order of points ) as g

(code probably does not work , but you get the idea )

http://postgis.net/docs/reference.html#Linear_Referencing

If you just want get subline from line between two points then usegeometry ST_LineSubstring(geometry a_linestring, float startfraction, float endfraction);you need to st_linelocatepoint() to find those fractions first


  • The POINT_REMOVE algorithm works by identifying and removing relatively redundant vertices to simplify data for display at smaller scales. It is the fastest of the simplification algorithm in this tool. This algorithm is often used for data compression or for coarse simplification. The angularity of the resulting line increases significantly as the tolerance increases. This algorithm is based on the Douglas-Peucker algorithm: Douglas, David and Peucker, Thomas, "Algorithms for the reduction of the number of points required to represent a digitized line or its caricature," The Canadian Cartographer 10(2), 112–122 (1973).
  • The BEND_SIMPLIFY algorithm works by identifying and eliminating relatively insignificant bends to simplify data for display at smaller scales. It is typically more faithful to the input geometry than the POINT_REMOVE algorithm but can take more time to process. It is slower but typically produces results that are more faithful to the original features. It operates by eliminating insignificant bends along lines. This algorithm is based on the algorithm defined in Wang, Zeshen and Müller, Jean-Claude, "Line Generalization Based on Analysis of Shape Characteristics," Cartography and Geographic Information Systems 25(1), 3–15 (1998).
  • The WEIGHTED_AREA algorithm works by first identifying triangles of effective area for each vertex. Those triangles are then weighted by a set of metrics to compare the flatness, skewness, and convexity of each area. The weighted areas guide the removal of their corresponding vertices to simplify the line while retaining as much character as possible. This algorithm is based on the algorithm defined in Zhou, Sheng and Jones, Christopher B., "Shape-Aware Line Generalisation with Weighted Effective Area," in Fisher, Peter F. (Ed.), Developments in Spatial Handling: 11th International Symposium on Spatial Handling, 369–80 (2005).
  • The EFFECTIVE_AREA algorithm works by identifying triangles of effective area for each vertex to guide the removal of vertices to simplify the line while retaining as much character as possible. This algorithm is based on the algorithm defined in Visvalingam, M and Whyatt, J. D., "Line Generalisation by Repeated Elimination of the Smallest Area," Cartographic Information Systems Research Group (CISRG) Discussion Paper 10, The University of Hull (1992).

The Simplification Tolerance parameter value determines the degree of simplification. The larger the tolerance, the more coarse the resulting geometry is. Smaller tolerances generate geometry more faithful to the input. MinSimpTol and MaxSimpTol fields are both added to the output to store the tolerance that was used.

Legacy:

In the course of topology resolution, versions of the tool prior to ArcGIS Desktop 10.5 modified tolerance on a per-feature basis and stored those values in the MinSimpTol and MaxSimpTol fields. Now the values in these fields will be the same and equal to the tolerance specified in the Simplification Tolerance parameter. Be sure to modify existing models or scripts that rely on any of these fields.

  • For the POINT_REMOVE algorithm, the tolerance is the maximum allowable perpendicular distance between each vertex and the new line created.
  • For the BEND_SIMPLIFY algorithm, the tolerance is the diameter of a circle that approximates a significant bend.
  • For the WEIGHTED_AREA algorithm, the square of the tolerance is the area of a significant triangle defined by three adjacent vertices. The further a triangle deviates from equilateral, the higher weight it is given, and the less likely it is to be removed.
  • For the EFFECTIVE_AREA algorithm, the square of the tolerance is the area of a significant triangle defined by three adjacent vertices.

Use the Keep collapsed points parameter ( collapsed_point_option in Python) to create an output point feature class to store the endpoints of any lines that are smaller than the spatial tolerance of the data. The point output is derived it will use the same name and location as the Output feature class ( out_feature_class in Python) but with a _Pnt suffix. The output line feature class contains all the fields present in the input feature class. The output point feature class does not contain any of these fields.

The output line feature class is topologically correct. Any topological errors in the input data are flagged in the output line feature class. The output feature class includes two additional fields: InLine_FID and SimLnFlag that contain the input feature IDs and topological errors of the input, respectively. A SimLnFlag value of 1 indicates a topological error is present 0 (zero) indicates that no errors are present.

Legacy:

Prior to the ArcGIS Desktop 10.5 version of this tool, topological errors could be generated during processing. The Check for topological errors ( error_checking_option in Python) and the Resolve topological errors ( error_resolving_option in Python) parameters were included to identify and optionally resolve these errors. These parameters are still included in the tool's syntax for compatibility in scripts and models but are now ignored and are hidden from the tool's dialog box. The SimLnFlag field was used to flag topological errors introduced by the tool in processing. Now this field flags errors present in the input.

Use the Input barrier layers parameter to identify features that must not be crossed by simplified lines. Barrier features can be points, lines, or polygons.

Processing large datasets may exceed memory limitations. In such cases, consider processing input data by partition by identifying a relevant polygon feature class in the Cartographic Partitions environment setting. Portions of the data, defined by partition boundaries, will be processed sequentially. The resulting feature class will be seamless and consistent at partition edges. See Generalizing large datasets using partitions for more information.


1. Broken scales show drama where it doesn't exist.

This is probably the most common way graphics lie, whether intentional or not. Something that changes by 0.1 percent over 10 years and something that changes by 1,000 percent in one year can look exactly the same depending on the scale, or range of values used on the chart.

It gets worse when we compare two different elements. In this case we’re not just adding drama to the change, we're making unfair comparisons.

That doesn’t mean that charts should never break a scale. Maybe we want to show deviation from 50%, and that should be our starting point. But there has to be a good reason to do it. Showing a more dramatic view of the change is not one.


Share

As if by providence, the day after I created The Upheaval, on April 8, the U.S. National Intelligence Council (NIC) released Global Trends 2040, the latest in a series of special documents published every four years by the NIC’s Strategic Futures Group to assess “the key trends and uncertainties that will shape the strategic environment for the United States during the next two decades.” So far no one seems to have paid much attention to it at all. I, however, read it with great interest, because lo and behold it essentially describes, with some precision, nothing less than the same pattern of tectonic revolutions beginning to drive global upheaval that I’d written on just the day before.

The report is a remarkable document.

While the analysts who wrote it are unable to describe what is happening inside the United States (in practice these reports are mostly produced by the CIA, given that outward facing strategic intelligence is their specialty, and the Agency is essentially forbidden from engaging on domestic matters), their prediction of where the world is headed as a whole is both shockingly dire and fascinating in its candid acknowledgement of the havoc that “identity politics” is unleashing on us all.

Describing the storm of structural forces now driving global change, the report quickly specifies that “many people are emphasizing and organizing around different aspects of their identities, including race, gender, and sexual orientation.” Noting that “identity-based beliefs tend to eclipse truth-seeking,” including because of the need to “feel morally justified,” it predicts that “the combination of newly prominent and diverse identity allegiances and a more siloed information environment is exposing and aggravating fault lines within states, undermining civic nationalism, and increasing volatility.”

“Identities and affiliations are simultaneously proliferating and becoming more pronounced. In turn, this is leading to more influential roles for identity groups in societal and political dynamics but also generating divisions and contention.” The result is that, “the expansion and increasing prominence of identity groups demanding recognition and rights are forcing an increase in debate about the social and economic foundations of societies. Intensifying and competing identity dynamics are likely to provoke increasing political debate and polarization, societal divisions, and in some cases, unrest and violence.”

This is exacerbated by the fact that “technological developments are likely to increase ever faster, transforming a range of human experiences and capabilities while also creating new tensions and disruptions within and between societies.” In particular, increased “connectivity will help produce new efficiencies, conveniences, and advances in living standards. However, it will also create and exacerbate tensions at all levels, from societies divided over core values and goals to regimes that employ digital repression to control populations.”

“All together,” the report says “these [technological] forces portend a world that is both inextricably bound by connectivity and fragmenting in different directions.”

We should be prepared for “more political volatility, including growing polarization and populism within political systems, waves of activism and protest movements, and, in the most extreme cases, violence, internal conflict, or even state collapse.” Such “outbreaks of political violence or internal conflict are not limited to… fragile states, however, and are likely to appear even in historically more stable countries.”

But that’s not all, because shifting balances of military and economic power, as well as “hardening divisions over governance models,” are “likely to further ratchet up competition between China and a Western coalition led by the United States.”

“This rivalry will affect most domains,” and “produce a more conflict-prone and volatile geopolitical environment,” while “the extent of ideological contest between the Western democratic model and China’s techno-authoritarian system, will shape democratic trends around the world.”

“Looking forward,” it warns, “many democracies are likely to be vulnerable to further erosion and even collapse.”

Then, in what I consider its most interesting lines, the report concludes that “historically, ideological shifts across regions have taken place at moments of catastrophic crisis,” but sufficient stresses “that expose governance shortcomings might create conditions ripe for new or alternative models to gain traction if widespread dysfunction is sustained.” Currently, “as a result of these disequilibriums, old orders—from institutions to norms to types of governance—are strained and in some cases, eroding. And actors at every level are struggling to agree on new models for how to structure civilization” (emphasis mine). These “shifts or transformations [will] spur inevitable contestation between the constituencies holding onto the old orders and those embracing the new ones.”

This could not better match what I outlined in the post introducing The Upheaval, where I argued that “the world is being forcibly reconfigured by at least three concurrent revolutions: a geopolitical revolution driven by the rise of China an ideological revolution consuming the Western world and a technological revolution exacerbating both of the former.” And, that what we are seeing may be essentially the death throes of 500 years of Western Enlightenment Liberalism.

The NIC’s report doesn’t ever mention the New Faith (oddly, you won’t find the word “Woke” used even once), of course, and it never takes a position at all on what is happening inside the country it aims to protect, but in my view it manages that say an awful lot in between the lines nonetheless by portraying everything as common “global challenges.”

How did this even come to pass in today’s climate? These reports are produced by a long process of internal consultation and consensus, so my guess is that – despite any ongoing proliferation of young intelligence officers partial to the New Faith within the institution – there are enough experienced senior analysts remaining within the system who know their stuff (that is: how states collapse) and are justifiably alarmed by what they see happening to push this out. Still, I’m frankly a bit surprised it made it past the censors.

The document is absolutely worth reading in full, with much more on geopolitics, climate change and other environmental stresses, and more. But I will copy a number of what I found to be the most interesting passages below as a sort of appendix, arranged by topic. Note that these paragraphs are not in any particular order. All emphasis in the below quotes is mine.

Appendix: Identity, Fracturing Societies, and Challenges to Democracy

The scale of transnational challenges, and the emerging implications of fragmentation, are exceeding the capacity of existing systems and structures, highlighting the third theme: disequilibrium. There is an increasing mismatch at all levels between challenges and needs with the systems and organizations to deal with them.

[The] difficulty of addressing these transnational challenges is compounded in part by increasing fragmentation within communities, states, and the international system. Paradoxically, as the world has grown more connected through communications technology, trade, and the movement of people, that very connectivity has divided and fragmented people and countries.

A key consequence of greater imbalance is greater contestation within communities, states, and the international community. This encompasses rising tensions, division, and competition in societies, states, and at the international level. Many societies are increasingly divided among identity affiliations and at risk of greater fracturing. Relationships between societies and governments will be under persistent strain as states struggle to meet rising demands from populations. As a result, politics within states are likely to grow more volatile and contentious, and no region, ideology, or governance system seems immune or to have the answers.

People are gravitating to familiar and like-minded groups for community and security, including ethnic, religious, and cultural identities as well as groupings around interests and causes, such as environmentalism. The combination of newly prominent and diverse identity allegiances and a more siloed information environment is exposing and aggravating fault lines within states, undermining civic nationalism, and increasing volatility.

Populations in every region are increasingly equipped with the tools, capacity, and incentive to agitate for their preferred social and political goals and to place more demands on their governments to find solutions. At the same time that populations are increasingly empowered and demanding more, governments are coming under greater pressure from new challenges and more limited resources. This widening gap portends more political volatility, erosion of democracy, and expanding roles for alternative providers of governance. Over time, these dynamics might open the door to more significant shifts in how people govern.

Potentially slower economic growth in coming years and smaller gains in human development in many countries are likely to exacerbate distrust of institutions and formal sources of authority for some members of the public. Trust in governments and institutions, which is highly dependent on perceptions of fairness and effectiveness, has been consistently low for the past decade, particularly in middle- to high-income countries. In a 2020 study of 16 developed countries by Edelman, the portion of the mass public trusting government since 2012 never exceeded 45 percent, and among Organization for Economic Cooperation and Development (OECD) economies, public trust in government fell in more than half of countries between 2006 and 2016, according to separate public opinion polling by Gallup. Of 11 geographically diverse countries analyzed by Edelman during the COVID-19 pandemic, public trust in government increased an average of 6 percentage points between January and May 2020, and then it declined an average of 5 percentage points between May 2020 and January 2021 as governments failed to contain the coronavirus.

Trust is not uniform across societies. Globally, trust in institutions among the informed public—defined as people who are college educated, are in the top 25 percent of household income in each market, and exhibit significant media consumption—has risen during the past 20 years whereas more than half of the mass public during the past decade repeatedly say the “system” is failing them. The gap in trust in institutions between the informed public and the mass public has increased during the past decade, according to the Edelman surveys, showing a gap of 5 percentage points in 2012 and 16 points in the 2021 report. Similarly, the gap in trust in business quadrupled during this period… In coming years, advancements in artificial intelligence (AI), machine learning, 5G, and other technologies that will expand access to the Internet could further diminish public trust as people struggle to determine what is real and what is rumor or manipulation. In addition, populations fear the increasingly pervasive surveillance and monitoring by governments and fear private corporations seeking control or profit from their personal information.

As trust in governments, elites, and other established institutions erodes, societies are likely tofragment further based on identities and beliefs. People in every region are turning to familiar and like-minded groups for community and a sense of security, including cultural and other subnational identities as well as transnational groupings and interests. Identities and affiliations are simultaneously proliferating and becoming more pronounced. In turn, this is leading to more influential roles for identity groups in societal and political dynamics but also generating divisions and contention.

Many people are gravitating to more established identities, such as ethnicity and nationalism. In some countries, slowing population growth, increasing migration, and other demographic shifts are intensifying perceptions of vulnerability, including a sense of cultural loss. Many people who feel displaced by rapid social and economic changes resent violations of age-old traditions and perceive that others are benefiting from the system at their expense. These perceptions also fuel beliefs that economic and social change is damaging and that some leaders are pursuing misguided goals.

Many people are emphasizing and organizing around different aspects of their identities, including race, gender, and sexual orientation, as well as around causes and issues, such as climate change and religious freedom. The forces of globalization, including greater mobility, urbanization, and connectivity, are increasing awareness and prominence of a wide array of constituencies that transcend national boundaries and are making it easier for people to organize around common interests and values. These identities are playing greater roles within and between countries as groups agitate for recognition and specific goals. For example, a broad global coalition has successfully lobbied for public acceptance of and legal protections for homosexuality worldwide, including organizing online campaigns and public events even in socially conservative countries, such as Iran. Between 2013 and 2019, the percentage of people indicating that homosexuality should be accepted in society increased in 21 of 27 geographically diverse countries, according to the Pew Research Center, and 30 countries have legalized same-sex marriage since 1989.

The expansion and increasing prominence of identity groups demanding recognition and rights are forcing an increase in debate about the social and economic foundations of societies.Intensifying and competing identity dynamics are likely to provoke increasing political debate and polarization, societal divisions, and in some cases, unrest and violence.

These structural forces, along with other factors, will intersect and interact at the levels of societies, states, and the international system, creating opportunities as well as challenges for communities, institutions, corporations, and governments. These interactions are also likely to produce greater contestation at all levels than has been seen since the end of the Cold War, reflecting differing ideologies as well as contrasting views on the most effective way to organize society and tackle emerging challenges.

Within states and societies, there is likely to be a persistent and growing gap between what people demand and what governments and corporations can deliver. From Beirut to Bogota to Brussels, people are increasingly taking to the streets to express their dissatisfaction with governments’ ability to meet a wide range of needs, agendas, and expectations. As a result of these disequilibriums, old orders—from institutions to norms to types of governance—are strained and in some cases, eroding. And actors at every level are struggling to agree on new models for how to structure civilization.

In coming years, this mismatch between governments’ abilities and publics’ expectations is likely to expand and lead to more political volatility, including growing polarization and populism within political systems, waves of activism and protest movements, and, in the most extreme cases, violence, internal conflict, or even state collapse. Variations in state capacity, ideology, and prior histories with mobilization will shape how and when public discontent translates into political volatility in each country.

Polarization and Populism. Polarization along ethnic, religious, and ideological lines is likely to remain strong, as political leaders and well-organized groups push a wide variety of broad goals and approaches that cut across economic, governance, social, identity, and international issues. In some countries, such polarization is likely to increase and reinforce political dysfunction and gridlock and heighten risks of political instability. Once established, severe polarization is difficult to reverse.

Protests. Antigovernment protests have increased globally since 2010, affecting every regime and government type. Although protests are a signal of political turbulence, they can also be a sign of democratic health and a force for democratization by pressing for accountability and political change. The protest phenomenon is likely to persist in cycles and waves because of the enduring nature of the underlying drivers, including ongoing public dissatisfaction and desire for systemic change, insufficient government responses, and pervasive technology to organize protests rapidly.

Political Violence, Internal Conflict, and State Collapse. During the next two decades, increased volatility is likely to lead to the breakdown of political order and outbreak of political violence in numerous countries, particularly in the developing world. As of 2020, 1.8 billion people—or 23 percent of the world’s population—lived in fragile contexts with weak governance, security, social, environmental, and economic conditions, according to an OECD estimate. This number is projected to grow to 2.2 billion—or 26 percent of the world’s population—by 2030. These states are mostly concentrated in Sub-Saharan Africa, followed by the Middle East and North Africa, Asia, and Latin America. These areas will also face an increasing combination of conditions, including climate change, food insecurity, youthful and growing populations (in Africa), and rapid urbanization, that will exacerbate state fragility. Outbreaks of political violence or internal conflict are not limited to these fragile states, however, and are likely to appear even in historically more stable countries when political volatility grows severe.

The challenges governments face suggest there is a high risk that an ongoing trend in erosion of democratic governance will continue during at least the next decade and perhaps longer. This trend has been widespread—seen in established, wealthy, liberal democracies as well as less mature partial democracies. Key democratic traits, including freedom of expression and the press, judicial independence, and protections for minorities, are deteriorating globally with countries sliding in the direction of greater authoritarianism. The democracy promotion nongovernmental organization (NGO) Freedom House reported that 2020 was the 15th consecutive year of decline in political rights and civil liberties. Another respected measure of democracy worldwide, Varieties of Democracy, indicates that as of 2020, 34 percent of the world’s population were living in countries where democratic governance was declining, compared with 4 percent who were living in countries that were becoming more democratic.

Several internal and external forces are driving this democratic erosion. In some Western democracies, public distrust of the capabilities and policies of established parties and elites, as well as anxieties about economic dislocations, status reversals, and immigration, have fueled the rise of illiberal leaders who are undermining democratic norms and institutions and civil liberties. In newer democracies—mostly in the developing world—that transitioned from authoritarian rule in the 1980s and 1990s, a mix of factors has led to democratic stagnation or backsliding, including weak state capacity, tenuous rule of law, fragile traditions of tolerance for opposition, high inequality, corruption, and militaries with a strong role in politics. Externally, China, Russia and other actors, in varying ways, are undermining democracies and supporting illiberal regimes. This support includes sharing technology and expertise for digital repression. In particular, some foreign actors are attempting to undermine public trust in elections, threatening the viability of democratic systems. Both internal and external actors are increasingly manipulating digital information and spreading disinformation to shape public views and achieve political objectives.

Looking forward, many democracies are likely to be vulnerable to further erosion and even collapse. An academic study of 75 democracies that experienced substantial democratic decline since 1994 found that 60 of them (80 percent) eventually became autocracies. However, the decline is not inexorable, and it may ultimately reflect a bad patch in a long cycle that has seen democracy advance and retreat with an overarching trend to more democracy during the past century. The long-term legitimacy of democratic systems hinges on two general conditions: maintaining a fair, inclusive, and equitable political process and delivering positive outcomes for populations. Addressing public concerns about corruption, elite capture, and inequality can help restore public trust and strengthen institutional legitimacy. In addition, providing effective services, economic stability, and personal security—historically advantages for democracies—increases public satisfaction. Beyond these basic governance benchmarks, demonstrating resilience to emerging global challenges will help restore and maintain public confidence.

Over the long term, the advance or retreat of democracy will depend in part on the relative power balance among major powers. Geopolitical competition, including efforts to influence or support political outcomes in other countries, relative success in delivering economic growth and public goods, and the extent of ideological contest between the Western democratic model and China’s techno-authoritarian system, will shape democratic trends around the world.

The combination of widespread public discontent and major crises or shocks could create conditions that are ripe for significant shifts or transformations in the models, ideologies, or ways of governing. Historically, ideological shifts across regions have taken place at moments of catastrophic crisis, such as in the wake of a major war or economic collapse, because people are more willing to embrace bold systemic changes to address overarching problems. However, the emergence of a new unifying ideology or system—on the scale of communism or economic liberalism—is rare. Other stresses, such as another pandemic or a major environmental catastrophe, that expose governance shortcomings might create conditions ripe for new or alternative models to gain traction if widespread dysfunction is sustained.

Pervasive discontent and major crises probably are necessary forcing functions for transformations but not sufficient. Transforming discontent into something new also requires the combination of inspiring and unifying leadership with compelling ideas or ideology to build political coalitions and garner societal consensus. Short of a new ideology, new approaches—or even more combinations or blends of systems—could occur along several axes, from centralized to localized governance, from a strong state role to a strong nonstate role, from democratic to authoritarian, from secular to religious, or from nationalist to internationalist. These shifts or transformations would spur inevitable contestation between the constituencies holding onto the old orders and those embracing the new ones.

The precise nature of these shifts, transformations, or new models is uncertain and difficult to foresee. Some potential outcomes include: cities or subnational regions emerging as the focal point for governance if populations see local governments as more trustworthy and capable of solving problems than national governments the private sector and other nonstate actors overtaking and displacing governments as the primary providers of welfare and security democracy experiencing a revival if it proves more adaptive to the coming global challenges or the world succumbing to an authoritarian wave partially inspired by China’s model of technology-driven authoritarian capitalism. Moreover, compelling new governance models or ideologies that have not yet been envisioned or identified could emerge and take hold.

Appendix: The Challenge of Technology

During the next two decades, the pace and reach of technological developments are likely to increase ever faster, transforming a range of human experiences and capabilities while also creating new tensions and disruptions within and between societies, industries, and states. State and nonstate rivals will vie for leadership and dominance in science and technology with potentially cascading risks and implications for economic, military, and societal security.

The Internet of Things encompassed 10 billion devices in 2018 and is projected to reach 64 billion by 2025 and possibly many trillions by 2040, all monitored in real time. In turn, this connectivity will help produce new efficiencies, conveniences, and advances in living standards. However, it will also create and exacerbate tensions at all levels, from societies divided over core values and goals to regimes that employ digital repression to control populations. As these connections deepen and spread, they are likely to grow increasingly fragmented along national, cultural, or political preferences. In addition, people are likely to gravitate to information silos of people who share similar views, reinforcing beliefs and understanding of the truth. Meanwhile, globalization is likely to endure but transform as economic and production networks shift and diversify. All together, these forces portend a world that is both inextricably bound by connectivity and fragmenting in different directions.

The exponential growth of the hyperconnected information environment is likely to strengthen and further complicate identity allegiance and societal dynamics. Social media, in particular, makes it easier for people to affiliate with others around the world who share common characteristics, views, and beliefs. Moreover, social media can create echo chambers of like-minded users who share information that confirms their existing worldviews and limits their understanding of alternative perspectives… Over time, this dynamic is increasing awareness of and building new connections between previously isolated groups, while also polarizing people’s perceptions of policies, public institutions, events, moral issues, and societal trends. Such polarization will lead to a proliferation of competing, entrenched perspectives, limiting opportunities for compromise and decreasing societal cohesion.

During the next 20 years, the algorithms and social media platforms that curate and distill massive amounts of data will produce content that could overtake expertise in shaping the political and social effects engendered by a hyperconnected information environment. Power increasingly will be wielded by the generators of content as well as the arbiters of who gets to see it.Social media platforms will reinforce identity groups, or foster new and unanticipated groupings, and accelerate and amplify natural tendencies to associate with people who share the same views, often engendering competing visions of the truth about an issue.

People will also use social identities such as culture, ethnicity, nationality, and religion as critical filters for managing information overload, potentially further fragmenting national identities and undermining trust in government. These identities provide a sense of belonging and reinforce norms about how group members should behave, rules about whom to trust, and beliefs about complex issues. Identity-based violence, including hate and political crimes, may increasingly be facilitated by social media.

Efforts to arbitrate controversial content, such as flagging or removing demonstrably false claims, are unlikely to be effective in changing beliefs and values aligned with one’s closely held identities, however. Identity-based beliefs tend to eclipse truth-seeking because of the overriding need to belong, obtain status, understand the social world, maintain dignity, and feel morally justified.

Governments will be hard pressed to keep up with the pace of technological change and implement policies that harness the benefits and mitigate the risks and disruptions. Technological advances will also empower individuals and nonstate actors to challenge the role of the state in new ways.

Appendix: China, Geopolitics and Geoeconomics

Accelerating shifts in military power, demographics, economic growth, environmental conditions, and technology, as well as hardening divisions over governance models, are likely to further ratchet up competition between China and a Western coalition led by the United States. Rival powers will jockey to shape global norms, rules, and institutions, while regional powers and nonstate actors may exert more influence and lead on issues left unattended by the major powers. These highly varied interactions are likely to produce a more conflict-prone and volatile geopolitical environment, undermine global multilateralism, and broaden the mismatch between transnational challenges and institutional arrangements to tackle them.

The United States and China will have the greatest influence on global dynamics, supporting competing visions of the international system and governance that reflect their core interests and ideologies. This rivalry will affect most domains, straining and in some cases reshaping existing alliances, international organizations, and the norms and rules that have underpinned the international order. In this more competitive global environment, the risk of interstate conflict is likely to rise because of advances in technology and an expanding range of targets, new frontiers for conflict and a greater variety of actors, more difficult deterrence, and a weakening or a lack of treaties and norms on acceptable use.

During the next two decades, the intensity of competition for global influence is likely to reach its highest level since the Cold War. No single state is likely to be positioned to dominate across all regions or domains, and a broader range of actors will compete to advance their ideologies, goals, and interests. Expanding technological, network, and information power will complement more traditional military, economic, and soft power aspects in the international system.

These power dynamics are likely to produce a more volatile and confrontational geopolitical environment, reshape multilateralism, and widen the gap between transnational challenges and cooperative arrangements to address them. Rival powers will jockey to shape global norms, rules, and institutions. The United States, along with its longstanding allies, and China will have the greatest influence on global dynamics, supporting competing visions of the international system and governance that reflect their core interests and ideologies. Their rivalry will affect most domains, straining and in some cases reshaping existing alliances and international organizations that have underpinned the international order for decades.

Accelerating power shifts—as well as hardening ideological differences and divisions over governance models—are likely to further ratchet up competition. The rivalry is unlikely to resemble the US-Soviet rivalry of the Cold War, however, because of the greater variety of actors in the international system that can shape outcomes, interdependence in various domains, and fewer exclusive ideological dividing lines.

This more competitive environment with rapidly emerging technologies is likely to be more volatile with a heightened risk of conflict, at least until states establish new rules, norms, and boundaries for the more disruptive areas of competition. States will face a combination of highly destructive and precise conventional and strategic weapons, cyber activity targeting civilian and military infrastructure, and a confusing disinformation environment. Regional actors, including spoilers such as Iran and North Korea, will jockey to advance their goals and interests, bringing more volatility and uncertainty to the system. At the same time, states may struggle to establish stable deterrence with these new systems, particularly if the rules and treaties governing them continue to erode or lag.

As sources of power expand and shift globally, the actors and the roles they play in shaping global dynamics will also change. No single actor will be positioned to dominate across all regions and in all domains, offering opportunities for a broader array of actors and increasing competition across all issues. The growing contest between China and the United States and its close allies is likely to have the broadest and deepest impact on global dynamics, including global trade and information flows, the pace and direction of technological change, the likelihood and outcome of interstate conflicts, and environmental sustainability. Even under the most modest estimates, Beijing is poised to continue to make military, economic, and technological advancements that shift the geopolitical balance, particularly in Asia.

In the next two decades, China almost certainly will look to assert dominance in Asia and greater influence globally, while trying to avoid what it views as excessive liabilities in strategically marginal regions. In Asia, China expects deference from neighbors on trade, resource exploitation, and territorial disputes. China is likely to field military capabilities that put US and allied forces in the region at heightened risk and to press US allies and partners to restrict US basing access. Beijing probably will tout the benefits of engagement while warning of severe consequences of defiance. China’s leaders almost certainly expect Taiwan to move closer to reunification by 2040, possibly through sustained and intensive coercion.

China will work to solidify its own physical infrastructure networks, software platforms, and trade rules, sharpening the global lines of techno-economic competition and potentially creating more balkanized systems in some regions. China is likely to use its infrastructure and technology-led development programs to tie countries closer and ensure elites align with its interests. China probably will continue to seek to strengthen economic integration with partners in the Middle East and Indian Ocean region, expand its economic penetration in Central Asia and the Arctic, and work to prevent countervailing coalitions from emerging. China is looking to expand exports of sophisticated domestic surveillance technologies to shore up friendly governments and create commercial and data-generating opportunities as well as leverage with client regimes. China is likely to use its technological advancements to field a formidable military in East Asia and other regions but prefers tailored deployments—mostly in the form of naval bases—rather than large troop deployments. At the same time, Beijing probably will seek to retain some important linkages to US and Western-led networks, especially in areas of greater interdependence such as finance and manufacturing.

China is likely to play a greater role in leading responses to confronting global challenges commensurate with its increasing power and influence, but Beijing will also expect to have a greater say in prioritizing and shaping those responses in line with its interests. China probably will look to other countries to offset the costs of tackling transnational challenges in part because Beijing faces growing domestic problems that will compete for attention and resources. Potential financial crises, a rapidly aging workforce, slowing productivity growth, environmental pressures, and rising labor costs could challenge the Chinese Communist Party and undercut its ability to achieve its goals. China’s aggressive diplomacy and human rights violations, including suppression of Muslim and Christian communities, could limit its influence, particularly its soft power.

Nonstate actors, such as NGOs, religious groups, and technology superstar firms, will have the resources and global reach to build and promote alternative networks that complement, compete with, or possibly bypass states. In the past several decades, nonstate actors and transnational movements have used growing international connections for collective action or to influence populations around the world. In some cases, these actors can shape or constrain state actions through lobbying leaders and mobilizing citizens. The influence of nonstate actors will vary and be subject to government intervention. China, the EU, and others are already moving to regulate or break up superstar firms, while Beijing is trying to control or suppress NGOs and religious organizations. Many nonstate actors are likely to try to push back on state efforts to consolidate sovereignty in newer frontiers, including cyberspace and space.

Governments and nonstate actors are increasingly able to exploit consumer behavior data and marketing techniques to microtarget messages to small audience segments. Propagandists could leverage AI, the Internet of Things, and other tools to tailor communications to large audiences, anticipate their reactions, and adapt messaging in near real time… Behavioral big data, which captures statistical patterns in human psychology and action, may also enable significant predictive power and capacity for personalized influence. If meaningful regulation does not exist, public relations firms and political consultants can offer disinformation as a regular service, increasing public distrust in political institutions.

As global power continues to shift, many of the relationships, institutions, and norms that have largely governed and guided behavior across issues since the end of the Cold War are likely to face increasing challenges. Competition in these areas has been on the rise for years with China, Russia, and other countries demanding a greater say. Disagreements are likely to intensify over the mission and conduct of these institutions and alliances, raising uncertainty about how well equipped they will be to respond to traditional and emerging issues. Over time, states may even abandon some aspects of this international order.

Rising and revisionist powers, led by China and Russia, are seeking to reshape the international order to be more reflective of their interests and tolerant of their governing systems. China and Russia continue to advocate for an order devoid of Western-origin norms that allows them to act with impunity at home and in their perceived spheres of influence. They are advocating for alternative visions of the role of the state and human rights and are seeking to roll back Western influence, but their alternative models differ significantly from each other. Russia is promoting traditional values and desires a Russian-dominated protectorate covering much of Eurasia. China seeks growing global acceptance of its current social system—namely the Chinese Communist Party’s monopoly on power and control over society—socialist market economy, and preferential trading system.

The multidimensional rivalry with its contrasting governing systems has the potential to add ideological dimensions to the power struggle. Although the evolving geopolitical competition is unlikely to exhibit the same ideological intensity as the Cold War, China’s leadership already perceives it is engaged in a long-term ideological struggle with the United States. Ideological contests most often play out in international organizations, standard-setting forums, regional development initiatives, and public diplomacy narratives.

Western democratic governments probably will contend with more assertive challenges to the Western-led political order from China and Russia. Neither has felt secure in an international order designed for and dominated by democratic powers, and they have promoted a sovereignty-based international order that protects their absolute authority within their borders and geographic areas of influence. China and Russia view the ideas and ideology space as opportunities to shape the competition without the need to use military force. Russia aims to engender cynicism among foreign audiences, diminish trust in institutions, promote conspiracy theories, and drive wedges in societies. As countries and nonstate actors jockey for ideological and narrative supremacy, control over digital communications platforms and other vehicles for dissemination of information will become more critical.

Western leadership of the intergovernmental organizations may further decline as China and Russia obstruct Western-led initiatives and press their own goals. China is working to re-mold existing international institutions to reflect its development and digital governance goals and mitigate criticism on human rights and infrastructure lending while simultaneously building its own alternative arrangements to push development, infrastructure finance, and regional integration, including the Belt and Road Initiative, New Development Bank, the Shanghai Cooperation Organization, and the Regional Comprehensive Economic Partnership.

Rapidly advancing technologies, including hypersonics and AI, are creating new or enhanced types of weapons systems while offering a wider array of potential targets, across military and civilian capabilities and including domestic infrastructure, financial systems, cyber, and computer networks. These technologies will give states a broader spectrum of coercive tools that fall below the level of kinetic attacks, which many states may be likely to favor as a means of achieving strategic effects while avoiding the political, economic, and human costs of direct violence and declaring hostilities. The result may be further muddied distinctions between sharpened competition and conflict, increasing the motivations for states to establish supremacy at each level of the escalation ladder.

Interstate kinetic conflicts—defined as direct engagement between the military forces of two or more adversaries in which at least one participant suffers substantial casualties or damage—are likely to escalate faster and with less warning than before, compressing response times and increasing pressure to delegate or even automate certain decisionmaking. Inexpensive sensors and data analytics could revolutionize real-time detection and processing by 2040, but many militaries most likely will still struggle to distill meanings and compile options for policymakers without AI and other algorithmic decisionmaking aids. This increased speed is likely to heighten the risk of miscalculation or inadvertent escalation to full-scale war.


2 Answers 2

The coordinates of the center point (cx,cy) of a line segment between points (x1,y1) and (x2,y2) are:

In other words it's just the average, or arithmetic mean, of the two pairs of x and y coordinate values.

For a multi-segmented line, or polyline, its logical center point's x and y coordinates are just the corresponding average of x and y values of all the points. An average is just the sum of the values divided by the number of them.

The general formulas to rotate a 2D point (x,y) θ radians around the origin (0,0) are:

To perform a rotation about a different center (cx, cy), the x and y values of the point need to be adjusted by first subtracting the coordinate of the desired center of rotation from the point's coordinate, which has the effect of moving (known in geometry as translating) it is expressed mathematically like this:

then rotating this intermediate point by the angle desired, and finally adding the x and y values of the point of rotation back to the x and y of each coordinate. In geometric terms, it's the following sequence of operations: Tʀᴀɴsʟᴀᴛᴇ ─► Rᴏᴛᴀᴛᴇ ─► Uɴᴛʀᴀɴsʟᴀᴛᴇ.

This concept can be extended to allow rotating a whole polyline about any arbitrary point—such as its own logical center—by just applying the math described to each point of each line segment within it.

To simplify implementation of this computation, the numerical result of all three sets of calculations can be combined and expressed with a pair of mathematical formulas which perform them all simultaneously. So a new point (x′,y′) can be obtained by rotating an existing point (x,y), θ radians around the point (cx, cy) by using:

Incorporating this mathematical/geometrical concept into your function produces the following:


ESO Skills Guide - All Skills in Elder Scrolls Online

Racial Skills

These are the Passive Skills that your chosen race begins with. Each race is different and their bonuses are minimal, yet important to min/maxers. Some races are more aligned towards certain class types than others. There are ten races in Elder Scrolls Online and they are: Breton, Redguard, Orsimer (Orc), Nord, Dunmer (Dark Elf), Argonian, Altmer (High Elf), Bosmer (Wood Elf), Khajiit and Imperial (only available if you buy the Imperial Edition).

Class Skills

These are the skills of your chosen class: Templar, Dragon Knight, Nightblade, Sorcerer, Warden and Necromancer. Each class has 3 skills lines to choose from that specialize in different aspects of their class. For instance the Templar class has a DPS line, buffing line and healing line. You can mix and match equipped skills from each line, but it is necessary to unlock the skills to be able to use them. Once unlocked they will remain so no matter which skills you use.

Weapon Skills

These are the skills that come paired with the weapon type you are using. The weapon styles are: Two-Handed, One-Handed and Shield , Dual Wield, Bow, Destruction Staff and Restoration Staff. You can use any weapons you wish in Elder Scrolls Online, so feel free to experiment with what you like best.

Armor Skills

Skills that depend on the type of armor you have equipped, granting you bonuses for having more of one type. The Armor types are: Light Armor, Medium Armor and Heavy Armor. You can use any combination of armors that you wish, so get creative.

Guild Skills

Through out your travels in Tamriel, you will undoubtedly come across a guild or two that you wish to join. The Fighters Guild, Mage's Guild and Undaunted have their own set of skills and you can mix and match them into your arsenal as well. The Thieves Guild, Dark Brotherhood and Psijic Order Skills were added with DLC and Chapters.

World Skills

These skills lines are Soul Magic, Scrying, Excavation , Vampire , Werewolf and Legerdemain. The Vampire and Werewolf Lines are acquired from another player at the specified ritual site or from being infected with enemies carrying Vampirism or Lycanthropy. Soul Magic is acquired from completing the introduction.

Alliance War Skills

These are skills obtained by participating in The Alliance War and have mostly PvP benefits. They are: Assault and Support. One can also become Emperor and gain Passive Skills of that line (most of which give some benefit after your reign as Emperor is over.

Trade Skills

These are the skills that allow a player to craft weapons, armor, runes and potions. These skills are selected by the player when leveling up. He or she may put points into any of the the crafting professions, but will only have enough points available to max out 2 of them. These skills points are shared with combat skill points. The professions are: Alchemy, Blacksmithing, Clothier, Enchanting, Jewelry Crafting, Provisioning and Woodworking.

Companion Skills

Companion Skills in Elder Scroll Online (ESO) is a new feature added with the Blackwood Chapter (Release June 2021). You can pick multiple skills for your Companions, make them more powerful and helpful in your adventures. Like your character, companion skills can be categorized as Class Skills, Weapon Skills, Armor Skills, Guild Skills, and Racial Skills. They can slot 5 normal skills and 1 Ultimate skill.


2 Answers 2

Having dealt with the same scenario, here's an overview of the approach that I took:

Get the new environment up and running, but don't give it any ability to issue certificates - use LoadDefaultTemplates=False in your capolicy.inf.

While the devices are still set to not issue any templates, get everything squared away with the new environment, AIA locations, CRL distribution, etc. Check health of all with the Enterprise PKI snap-in.

Then, when you're ready, alter the config of the existing CA to stop issuing certificates for certain templates. You aren't killing the server yet, just telling it to stop issuing new certs. Add those same templates to the allowed issuance policies of your new environment.

Then, use the "re-enroll certificate holders" option on the template management tool for the templates that have certificates out there and are auto-enrolled (user, computer, and domain controller certs). This will bump the template version and cause them to grab a new certificate from the new infrastructure when their autoenroll pulses.

This will cover you for those certs, but for web server certs it'll unfortunately be a manual process. Re-issue for each, and change listeners to the new certs.

Once you're fairly confident that you've got all the certificates re-issued, cripple the old CA but don't remove the role yet. Do something along the lines of removing all AIA or CRL distribution points in the CA's configuration, then deleting the files/objects from those locations (LDAP is probably the main one, but http and smb need checking too). Wait for issues for a few weeks when something breaks, you can re-add the AIA/CRL points that you deleted and re-publish ( certutil -dspublish ) if needed.

Once you're satisfied that nothing's using the old CA anymore, remove the role, then clean up Active Directory. The AIA, CRLs, and delta CRLs need a manual delete, which you can do in the "Manage AD Containers" option in the Enterprise PKI snap-in.


Evaluate

Hands-On Evaluation

To evaluate System Architect, please send an email to [email protected] In the subject field ask for an Evaluation Request for System Architect. Sales will ask you for specific information to qualify you for the evaluation.

Request for Information

If you would like to submit a Request for Information for an Enterprise Architecture tool, please send an email to [email protected]

Watch the Product In Action


Contents

Ancient times Edit

What is the earliest known map is a matter of some debate, both because the term "map" is not well-defined and because some artifacts that might be maps might actually be something else. A wall painting that might depict the ancient Anatolian city of Çatalhöyük (previously known as Catal Huyuk or Çatal Hüyük) has been dated to the late 7th millennium BCE. [1] [2] Among the prehistoric alpine rock carvings of Mount Bego (France) and Valcamonica (Italy), dated to the 4th millennium BCE, geometric patterns consisting of dotted rectangles and lines are widely interpreted [3] [4] in archaeological literature as a depiction of cultivated plots. [5] Other known maps of the ancient world include the Minoan "House of the Admiral" wall painting from c. 1600 BCE, showing a seaside community in an oblique perspective, and an engraved map of the holy Babylonian city of Nippur, from the Kassite period (14th – 12th centuries BCE). [6] The oldest surviving world maps are from 9th century BCE Babylonia. [7] One shows Babylon on the Euphrates, surrounded by Assyria, Urartu [8] and several cities, all, in turn, surrounded by a "bitter river" (Oceanus). [9] Another depicts Babylon as being north of the center of the world. [7]

The ancient Greeks and Romans created maps from the time of Anaximander in the 6th century BCE. [10] In the 2nd century CE, Ptolemy wrote his treatise on cartography, Geographia. [11] This contained Ptolemy's world map – the world then known to Western society (Ecumene). As early as the 8th century, Arab scholars were translating the works of the Greek geographers into Arabic. [12]

In ancient China, geographical literature dates to the 5th century BCE. The oldest extant Chinese maps come from the State of Qin, dated back to the 4th century BCE, during the Warring States period. In the book of the Xin Yi Xiang Fa Yao, published in 1092 by the Chinese scientist Su Song, a star map on the equidistant cylindrical projection. [13] [14] Although this method of charting seems to have existed in China even before this publication and scientist, the greatest significance of the star maps by Su Song is that they represent the oldest existent star maps in printed form.

Early forms of cartography of India included depictions of the pole star and surrounding constellations. [15] These charts may have been used for navigation. [15]

Middle Ages and Renaissance Edit

Mappae mundi ("maps of the world") are the medieval European maps of the world. About 1,100 of these are known to have survived: of these, some 900 are found illustrating manuscripts and the remainder exist as stand-alone documents. [16]

The Arab geographer Muhammad al-Idrisi produced his medieval atlas Tabula Rogeriana (Book of Roger) in 1154. By combining the knowledge of Africa, the Indian Ocean, Europe, and the Far East (which he learned through contemporary accounts from Arab merchants and explorers) with the information he inherited from the classical geographers, he was able to write detailed descriptions of a multitude of countries. Along with the substantial text he had written, he created a world map influenced mostly by the Ptolemaic conception of the world, but with significant influence from multiple Arab geographers. It remained the most accurate world map for the next three centuries. [17] [18] The map was divided into seven climatic zones, with detailed descriptions of each zone. As part of this work, a smaller, circular map was made depicting the south on top and Arabia in the center. Al-Idrisi also made an estimate of the circumference of the world, accurate to within 10%. [19]

In the Age of Exploration, from the 15th century to the 17th century, European cartographers both copied earlier maps (some of which had been passed down for centuries) and drew their own, based on explorers' observations and new surveying techniques. The invention of the magnetic compass, telescope and sextant enabled increasing accuracy. In 1492, Martin Behaim, a German cartographer, made the oldest extant globe of the Earth. [20]

In 1507, Martin Waldseemüller produced a globular world map and a large 12-panel world wall map (Universalis Cosmographia) bearing the first use of the name "America". Portuguese cartographer Diego Ribero was the author of the first known planisphere with a graduated Equator (1527). Italian cartographer Battista Agnese produced at least 71 manuscript atlases of sea charts. Johannes Werner refined and promoted the Werner projection. This was an equal-area, heart-shaped world map projection (generally called a cordiform projection) which was used in the 16th and 17th centuries. Over time, other iterations of this map type arose most notable are the sinusoidal projection and the Bonne projection. The Werner projection places its standard parallel at the North Pole a sinusoidal projection places its standard parallel at the equator and the Bonne projection is intermediate between the two. [21] [22]

In 1569, mapmaker Gerardus Mercator first published a map based on his Mercator projection, which uses equally-spaced parallel vertical lines of longitude and parallel latitude lines spaced farther apart as they get farther away from the equator. By this construction, courses of constant bearing are conveniently represented as straight lines for navigation. The same property limits its value as a general-purpose world map because regions are shown as increasingly larger than they actually are the further from the equator they are. Mercator is also credited as the first to use the word "atlas" to describe a collection of maps. In the later years of his life, Mercator resolved to create his Atlas, a book filled with many maps of different regions of the world, as well as a chronological history of the world from the Earth's creation by God until 1568. He was unable to complete it to his satisfaction before he died. Still, some additions were made to the Atlas after his death and new editions were published after his death. [23] [24]

In the Renaissance, maps were used to impress viewers and establish the owner's reputation as sophisticated, educated, and worldly. Because of this, towards the end of the Renaissance, maps were displayed with equal importance of painting, sculptures, and other pieces of art. [25] In the sixteenth century, maps were becoming increasingly available to consumers through the introduction of printmaking, with about 10% of Venetian homes having some sort of map by the late 1500s.

There were three main functions of maps in the Renaissance: [26]

  • General descriptions of the world
  • Navigation and wayfinding
  • Land surveying and property management

In medieval times, written directions of how to get somewhere were more common than the use of maps. With the Renaissance, cartography began to be seen as a metaphor for power. [26] Political leaders could lay claim on territories through the use of maps and this was greatly aided by the religious and colonial expansion of Europe. The most commonly mapped places during the Renaissance were the Holy Land and other religious places.

In the late 1400s to the late 1500s, Rome, Florence, and Venice dominated map making and trade. It started in Florence in the mid to late 1400s. Map trade quickly shifted to Rome and Venice but then was overtaken by atlas makers in the late 16th century. [27] Map publishing in Venice was completed with humanities and book publishing in mind, rather than just informational use.

Printing technology Edit

There were two main printmaking technologies in the Renaissance: woodcut and copper-plate intaglio, referring to the medium used to transfer the image onto paper.

In woodcut, the map image is created as a relief chiseled from medium-grain hardwood. The areas intended to be printed are inked and pressed against the sheet. Being raised from the rest of the block, the map lines cause indentations in the paper that can often be felt on the back of the map. There are advantages to using relief to make maps. For one, a printmaker doesn't need a press because the maps could be developed as rubbings. Woodblock is durable enough to be used many times before defects appear. Existing printing presses can be used to create the prints rather than having to create a new one. On the other hand, it is hard to achieve fine detail with the relief technique. Inconsistencies in linework are more apparent in woodcut than in intaglio. To improve quality in the late fifteenth century, a style of relief craftsmanship developed using fine chisels to carve the wood, rather than the more commonly used knife.

In intaglio, lines are engraved into workable metals, typically copper but sometimes brass. The engraver spreads a thin sheet of wax over the metal plate and uses ink to draw the details. Then, the engraver traces the lines with a stylus to etch them into the plate beneath. [28] The engraver can also use styli to prick holes along the drawn lines, trace along them with colored chalk, and then engrave the map. Lines going in the same direction are carved at the same time, and then the plate is turned to carve lines going in a different direction. To print from the finished plate, ink is spread over the metal surface and scraped off such that it remains only in the etched channels. Then the plate is pressed forcibly against the paper so that the ink in the channels is transferred to the paper. The pressing is so forceful that it leaves a "plate mark" around the border of the map at the edge of the plate, within which the paper is depressed compared to the margins. [29] Copper and other metals were expensive at the time, so the plate was often reused for new maps or melted down for other purposes. [29]

Whether woodcut or intaglio, the printed map is hung out to dry. Once dry, it is usually placed in another press to flatten the paper. Any type of paper that was available at the time could be used to print the map on, but thicker paper was more durable.

Both relief and intaglio were used about equally by the end of the fifteenth century.

Lettering Edit

Lettering in mapmaking is important for denoting information. Fine lettering is difficult in woodcut, where it often turned out square and blocky, contrary to the stylized, rounded writing style popular in Italy at the time. [29] To improve quality, mapmakers developed fine chisels to carve the relief. Intaglio lettering did not suffer the troubles of a coarse medium and so was able to express the looping cursive that came to be known as cancellaresca. [29] There were custom-made reverse punches that were also used in metal engraving alongside freehand lettering. [28]

Color Edit

The first use of color in map making cannot be narrowed down to one reason. There are arguments that color started as a way to indicate information on the map, with aesthetics coming second. There are also arguments that color was first used on maps for aesthetics but then evolved into conveying information. [29] Either way, many maps of the Renaissance left the publisher without being colored, a practice that continued all the way into the 1800s. However, most publishers accepted orders from their patrons to have their maps or atlases colored if they wished. Because all coloring was done by hand, the patron could request simple, cheap color, or more expensive, elaborate color, even going so far as silver or gold gilding. The simplest coloring was merely outlines, such as of borders and along rivers. Wash color meant painting regions with inks or watercolors. Limning meant adding silver and gold leaf to the map to illuminate lettering, heraldic arms, or other decorative elements.

Early-Modern Period Edit

The Early Modern Period saw the convergence of cartographical techniques across Eurasia and the exchange of mercantile mapping techniques via the Indian Ocean. [30]

In the early seventeenth century, the Selden map was created by a Chinese cartographer. Historians have put its date of creation around 1620, but there is debate in this regard. This map's significance draws from historical misconceptions of East Asian cartography, the main one being that East Asians didn't do cartography until Europeans arrived. The map's depiction of trading routes, a compass rose, and scale bar points to the culmination of many map-making techniques incorporated into Chinese mercantile cartography. [31]

In 1689, representatives of the Russian tsar and Qing Dynasty met near the border town of Nerchinsk, which was near the disputed border of the two powers, in eastern Siberia. [32] The two parties, with the Qing negotiation party bringing Jesuits as intermediaries, managed to work a treaty which placed the Amur River as the border between the Eurasian powers, and opened up trading relations between the two. This treaty's significance draws from the interaction between the two sides, and the intermediaries who were drawn from a wide variety of nationalities.

The Enlightenment Edit

Maps of the Enlightenment period practically universally used copper plate intaglio, having abandoned the fragile, coarse woodcut technology. Use of map projections evolved, with the double hemisphere being very common and Mercator's prestigious navigational projection gradually making more appearances.

Due to the paucity of information and the immense difficulty of surveying during the period, mapmakers frequently plagiarized material without giving credit to the original cartographer. For example, a famous map of North America known as the "Beaver Map" was published in 1715 by Herman Moll. This map is a close reproduction of a 1698 work by Nicolas de Fer. De Fer, in turn, had copied images that were first printed in books by Louis Hennepin, published in 1697, and François Du Creux, in 1664. By the late 18th century, mapmakers often credited the original publisher with something along the lines of, "After [the original cartographer]" in the map's title or cartouche. [33]


3 Answers 3

Since you have plenty of room in /home , move all the stuff from /srv into /home , then (optionally) move the stuff that was in /home to the root partition.

The simplest solution, if you don't mind a few minutes' downtime, is to move /srv into the larger partition and symlink it:

If you really want to move /home to the root partition, then it takes a few renames. I assume there's no directory called /home/srv or /srv/srv .

Finally (if you're not using the symbolic link method) edit /etc/fstab to change the mount point: on the line that begins with /dev/sda9 /home , replace /home by /srv .

Before you do anything you're going to have to figure out a place to keep the 180 megabytes of data that /home is currently taking up. I'd recommend repartitioning the current /dev/sda9 into, say, two gigs for /home and 42 for /srv .

Next up you're going to have to be a little tricky. This is all best accomplished in single user mode so that only root is logged on and you don't run into trouble with someone trying to access /home while you're moving it around.

You've got a decent amount of room in /var, so we'll use that as a temporary holding space: mkdir /var/tmp/oldhome

`tar -cvf - ./ | ( cd /var/tmp/oldhome && tar -xvf - )

Now we've got /home backed up to someplace while we repartition /dev/sda9 into 2 gigs for /dev/sda9 and 42 gigs for /dev/sda10

Once you've finished repartitioning and creating new filesystems (I'm going to assume you know how to do this) you'll need to edit /etc/fstab .

Somewhere in there you'll see a line saying something along the lines of

/dev/sda9 /home ext3 defaults 0 2

Assuming that you've made /dev/sda9 the smaller of the two partitions, you can leave that line unchanged you'll just need to add