Cartographic Generalization
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Cartographic Generalization
Cartographic generalization, or map generalization, includes all changes in a map that are made when one derives a scale (map), smaller-scale map from a larger-scale map or map data, or vice versa. It is a core part of cartographic design. Whether done manually by a cartographer or by a computer or set of algorithms, generalization seeks to abstract geospatial information, spatial information at a high Level of detail (computer graphics), level of detail to information that can be rendered on a map at a lower level of detail. For example, we might have the outlines of all of the thousands of buildings in a region, but we wish to make a map of the whole city no more than a few inches wide. Instead of throwing out the building information, or trying to render it all at once, we could generalize the data into some sort of outline of the urban area, urbanized area of the region. The cartographer has license to adjust the content within their maps to create a suitable and useful map that ...
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Scale (map)
The scale of a map A map is a symbol A symbol is a mark, sign, or that indicates, signifies, or is understood as representing an , , or . Symbols allow people to go beyond what is n or seen by creating linkages between otherwise very different s and s. A ... is the ratio In mathematics, a ratio indicates how many times one number contains another. For example, if there are eight oranges and six lemons in a bowl of fruit, then the ratio of oranges to lemons is eight to six (that is, 8∶6, which is equivalent to ... of a distance on the map to the corresponding distance on the ground. This simple concept is complicated by the curvature of the Earth Earth is the third planet from the Sun and the only astronomical object known to harbour and support life. 29.2% of Earth's surface is land consisting of continents and islands. The remaining 70.8% is Water distribution on Earth, covered wi ...'s surface, which forces scale to vary across a map. Because of thi ...
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Edward Tufte
Edward Rolf Tufte (; born March 14, 1942), sometimes known as "ET",. is an American statistician and professor emeritus of political science, statistics, and computer science at Yale University. He is noted for his writings on information design and as a pioneer in the field of data visualization. Biography Edward Rolf Tufte was born in 1942 in Kansas City, Missouri, to Virginia Tufte (1918–2020) and Edward E. Tufte (1912–1999). He grew up in Beverly Hills, California, where his father was a longtime city official, and he graduated from Beverly Hills High School.Reynolds, Christopher."ART; Onward means going upward; Edward Tufte has spent his career fighting the visually dull and flat. Even his sculpture is a leap." ''Los Angeles Times'', November 14, 2002. Accessed April 23, 2008. "[Edward Tufte], who shares in Cheshire, Conn., with his wife, graphic design professor Inge Druckrey, and three golden retrievers, is a 1960 graduate of Beverly Hills High School." He received a ...
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Map Symbol
A map symbol is a graphical device used to visually represent a real-world feature on a map A map is a symbol A symbol is a mark, sign, or that indicates, signifies, or is understood as representing an , , or . Symbols allow people to go beyond what is n or seen by creating linkages between otherwise very different s and s. A ..., working in the same fashion as other forms of symbol A symbol is a mark, sign, or word In linguistics, a word of a spoken language can be defined as the smallest sequence of phonemes that can be uttered in isolation with semantic, objective or pragmatics, practical meaning (linguistics), m ...s. Map symbols may include point markers, lines, regions, continuous fields, or text; these can be designed visually in their shape, size, color, pattern, and other graphic variables to represent a variety of information about each phenomenon being represented. Map symbols simultaneously serve several purposes: * Declare the existence of g ...
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Geographic Information Systems
A geographic information system (GIS) is a type of database containing Geographic data and information, geographic data (that is, descriptions of phenomena for which location is relevant), combined with Geographic information system software, software tools for managing, Spatial analysis, analyzing, and Cartographic design, visualizing those data. In a broader sense, one may consider such a system to also include human users and support staff, procedures and workflows, body of knowledge of relevant concepts and methods, and institutional organizations. The uncounted plural, ''geographic information systems'', also abbreviated GIS, is the most common term for the industry and profession concerned with these systems, and is thus roughly synonymous with geospatial and geoinformatics. Geographic information science, the academic discipline that studies these systems and their underlying geographic principles, may also be abbreviated as GIS, but the unambiguous GIScience is more comm ...
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Dimension
In physics Physics is the that studies , its , its and behavior through , and the related entities of and . "Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular succession of eve ... and mathematics Mathematics (from Greek: ) includes the study of such topics as numbers (arithmetic and number theory), formulas and related structures (algebra), shapes and spaces in which they are contained (geometry), and quantities and their changes (cal ..., the dimension of a mathematical space In mathematics Mathematics (from Ancient Greek, Greek: ) includes the study of such topics as quantity (number theory), mathematical structure, structure (algebra), space (geometry), and calculus, change (mathematical analysis, analysis). ... (or object) is informally defined as the minimum number of coordinates In geometry Geometry (from the grc, γεωμετρία; ''wikt:γῆ, geo-'' "earth" ...
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Waldo Tobler
Waldo Rudolph Tobler (November 16, 1930 – February 20, 2018) was an United States, American-Switzerland, Swiss geographer and cartographer. Tobler's idea that "Everything is related to everything else, but near things are more related than distant things" is referred to as the "first law of geography." He has proposed a second law as well: "The phenomenon external to an area of interest affects what goes on inside". Tobler was an active Professor Emeritus at the University of California, Santa Barbara Department of Geography until his death. Academic background In 1961, Tobler received his Doctor of Philosophy, Ph.D. in the Department of Geography, University of Washington, Department of Geography at the University of Washington at Seattle. At Washington, he participated in geography's William Garrison (geographer), William Garrison-led quantitative revolution of the late 1950s. After graduating in 1961, Tobler became an Assistant Professor at the University of Michigan, where ...
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Kernel Smoother
A kernel smoother is a statistics, statistical technique to estimate a real valued function (mathematics), function f: \mathbb^p \to \mathbb as the weighted average of neighboring observed data. The weight is defined by the kernel, such that closer points are given higher weights. The estimated function is smooth, and the level of smoothness is set by a single parameter. Definitions Let K_(X_0 ,X) be a kernel defined by :K_(X_0 ,X) = D\left( \frac \right) where: * X,X_0 \in \mathbb^p * \left\, \cdot \right\, is the Euclidean norm * h_\lambda (X_0) is a parameter (kernel radius) * ''D''(''t'') is typically a positive real valued function, whose value is decreasing (or not increasing) for the increasing distance between the ''X'' and ''X''0. Popular Kernel (statistics), kernels used for smoothing include parabolic (Epanechnikov), Tricube, and Gaussian function, Gaussian kernels. Let Y(X):\mathbb^p \to \mathbb be a continuous function of ''X''. For each X_0 \in \mathbb^p, th ...
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Field (geography)
In the context of spatial analysis, geographic information systems, and geographic information science, a field is a property that fills space, and varies over space, such as temperature or density. This use of the term has been adopted from physics and mathematics, due to their similarity to field (physics), physical fields (vector field, vector or scalar field, scalar) such as the electromagnetic field or gravitational field. Synonymous terms include Spatial dependence , spatially dependent variable (geostatistics), statistical surface (thematic map , thematic mapping), and intensive property (physics and chemistry) and crossbreeding between these disciplines is common. The simplest formal model for a field is the function (mathematics), function, which yields a single value given a point in space (i.e., ''t'' = ''f''(''x'', ''y'', ''z'') ) History The modeling and analysis of fields in geographic applications was developed in five essentially separate movements, all of which ...
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Raster Graphics
upright=1, The Smiley, smiley face in the top left corner is a raster image. When enlarged, individual pixels appear as squares. Enlarging further, each pixel can be analyzed, with their colors constructed through combination of the values for red, green and blue. In computer graphics and digital photography Digital photography uses cameras A camera is an optical Optics is the branch of physics Physics (from grc, φυσική (ἐπιστήμη), physikḗ (epistḗmē), knowledge of nature, from ''phýsis'' 'nature'), , is the ..., a raster graphic is a mechanism that represents a two-dimensional image as a rectangular matrix or grid of square pixel In digital imaging Digital imaging or digital image acquisition is the creation of a representation of the visual characteristics of an object, such as a physical scene or the interior structure of an object. The term is often assumed to imp ...s, viewable via a computer display A computer monito ...
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Ramer–Douglas–Peucker Algorithm
The Ramer–Douglas–Peucker algorithm, also known as the Douglas–Peucker algorithm and iterative end-point fit algorithm, is an algorithm that Decimation (signal processing), decimates a curve composed of line segments to a similar curve with fewer points. It was one of the earliest successful algorithms developed for cartographic generalization. Idea The purpose of the algorithm is, given a Polygonal chain, curve composed of line segments (which is also called a ''Polyline'' in some contexts), to find a similar curve with fewer points. The algorithm defines 'dissimilar' based on the maximum distance between the original curve and the simplified curve (i.e., the Hausdorff distance between the curves). The simplified curve consists of a subset of the points that defined the original curve. Algorithm The starting curve is an ordered set of points or lines and the distance dimension ''ε'' > 0. The algorithm recursion, recursively divides the line. Initia ...
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Line Generalize
Line, lines, The Line, or LINE may refer to: Arts, entertainment, and media Films * Lines (film), ''Lines'' (film), a 2016 Greek film * The Line (2017 film), ''The Line'' (2017 film) * The Line (2009 film), ''The Line'' (2009 film) * ''The Line'', a 2009 independent film by Nancy Schwartzman Literature * Line (comics), a term to describe a subset of comic book series by a publisher * Line (play), ''Line'' (play), by Israel Horovitz, 1967 * Line (poetry), the fundamental unit of poetic composition * Lines (poem), "Lines" (poem), an 1837 poem by Emily Brontë * The Line (memoir), ''The Line'' (memoir), by Arch and Martin Flanagan * The Line (play), ''The Line'' (play), by Timberlake Wertenbaker, 2009 Music Albums * Lines (The Walker Brothers album), ''Lines'' (The Walker Brothers album), 1976 * Lines (Pandelis Karayorgis album), ''Lines'' (Pandelis Karayorgis album), 1995 * Lines (Unthanks album), ''Lines'' (Unthanks album), 2018 Songs * Line (song), "Line" (song), 2017 single ...
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Natural Earth
Natural Earth is a public domain map data set, dataset available at 1:10 million (1 cm = 100 km), 1:50 million, and 1:110 million map scales. Natural Earth's data set contains integrated vector and raster mapping data. The original authors of the map dataset are Tom Patterson and Nathaniel Vaughn Kelso, but Natural Earth has expanded to be a collaboration of many volunteers and is supported by the North American Cartographic Information Society (NACIS).Natural Earth Contributors
It is free for public use in any type of project. The dataset includes the fictitious 1-meter-square Null Island at for error-checking purposes.


Public domain data and software

All versions of Natural Earth Raster graphics, raster and Vector graphics, vector map data on the Natural Earth website are in the ...
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