Proximity analysis is a class of

spatial analysis Spatial analysis or spatial statistics includes any of the formal techniques Technique or techniques may refer to: Music * The Techniques, a Jamaican rocksteady vocal group of the 1960s *Technique (band), a British female synth pop band in the ...

tools and algorithms that employ geographic distance as a central principle.Blinn, Charles R., Lloyd P. Queen, and Les W. Maki,
"Geographic Information Systems: A Glossary."
'' Proximity analysis is a crucial tool for business marketing and

site selection The award-winning ''Site Selection'' magazine, published by Conway Data, Inc., is the official publication of thIndustrial Asset Management Council(IAMC). The magazine delivers expansion planning information to over 44,000 readers including corpora ...

. Marketers analyze demographics and infrastructure to determine trade areas. Trade areas are continuous geographic areas around a site that generate the majority of revenue. Proximity Analysis is a study using

location intelligence In business intelligence, location intelligence (LI), or spatial intelligence, is the process of deriving meaningful insight from geographic data and information, geospatial data relationships to solve a particular problem. It involves layering mu ...

, mapping software, to calculate the distances between customer/prospect locations, to your location(s) (retail store, bank, restaurant, dealer, or sales reps) as the first step in building an understanding of trade/sales/service area(s). An analysis typically includes a report and map showing the relationship of the data and often includes competitor locations in the analysis.

Techniques

There are a variety of tools, models, and algorithms that incorporate geographic distance, due to the variety of relevant problems and tasks. That said, almost all are fundamentally based on a few core principles of

geography Geography (from Greek: , ''geographia''. Combination of Greek words ‘Geo’ (The Earth) and ‘Graphien’ (to describe), literally "earth description") is a field of science devoted to the study of the lands, features, inhabitants, a ...

, such as the

friction of distance Friction of distance is a core principle of Geography that states that movement incurs some form of cost, in the form of physical effort, energy, time, and/or the expenditure of other resources, and that these costs are proportional to the distan ...

Tobler's first law of geography The First Law of Geography, according to Waldo Tobler, is "everything is related to everything else, but near things are more related than distant things." This first law is the foundation of the fundamental concepts of spatial dependence and spatia ...

, and

Spatial autocorrelation Spatial analysis or spatial statistics includes any of the formal techniques which studies entities using their topological, geometric, or geographic properties. Spatial analysis includes a variety of techniques, many still in their early devel ...

* Buffers, a tool for determining the region that is within a specified distance of a set of geographic features. * Cost distance analysis, an algorithm for finding optimal routes through continuous space that minimize distance and/or other location dependent costs. *

Voronoi diagram In mathematics, a Voronoi diagram is a partition of a plane into regions close to each of a given set of objects. In the simplest case, these objects are just finitely many points in the plane (called seeds, sites, or generators). For each seed ...

, also known as Thiessen polygons, an algorithm for partitioning continuous space into a set of regions based on a set of point locations, such that each region consists of locations that are closer to one of the points than any others. *

Distance decay Distance decay is a geographical term which describes the effect of distance on cultural or spatial interactions. The distance decay effect states that the interaction between two locales declines as the distance between them increases. Once the di ...

, based on the

Inverse square law In science, an inverse-square law is any scientific law stating that a specified physical quantity is inversely proportional to the square of the distance from the source of that physical quantity. The fundamental cause for this can be understo ...

, a mathematical model of how the influence of a phenomenon tends to be inversely proportional to the distance from it. A

Gravity model Gravity models are used in various social sciences to predict and describe certain behaviors that mimic gravitational interaction as described in Isaac Newton's laws of gravity. Generally, the social science models contain some elements of mass and ...

is a similar model. * Location analysis, a set of (usually heuristic) algorithms for finding the optimal locations of a limited set of points (e.g., store locations) that minimize the aggregate distance to another set of points (e.g., customer locations). A commonly used example is

Lloyd's algorithm In electrical engineering and computer science, Lloyd's algorithm, also known as Voronoi iteration or relaxation, is an algorithm named after Stuart P. Lloyd for finding evenly spaced sets of points in subsets of Euclidean spaces and partitions of ...

. *

Distance matrix In mathematics, computer science and especially graph theory, a distance matrix is a square matrix In mathematics, a square matrix is a matrix with the same number of rows and columns. An ''n''-by-''n'' matrix is known as a square matrix of orde ...

, an array containing the distances (Euclidean or otherwise) between any two points in a set. This is frequently used as the independent variable in statistical tests of whether the strength of a relationship is correlated with distance, such as the volume of trade between cities. Dijkstra_Animation

Transport network analysis A transport network, or transportation network, is a network or graph in geographic space, describing an infrastructure that permits and constrains movement or flow. Examples include but are not limited to road networks, railways, air routes, ...

, a set of algorithms and tools for solving a number of distance routing problems when travel is constrained to a network of one-dimensional lines, such as roads and utility networks. For example, the common task of finding the shortest route from point A to point B, which is typically solved using

Dijkstra's algorithm Dijkstra's algorithm ( ) is an algorithm for finding the shortest paths between nodes in a graph, which may represent, for example, road networks. It was conceived by computer scientist Edsger W. Dijkstra in 1956 and published three years ...

References

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External links

OGC ST_DWithin function
(

PostGIS PostGIS ( ) is an open source software program that adds support for geographic objects to the PostgreSQL object-relational database. PostGIS follows the Simple Features for SQL specification from the Open Geospatial Consortium (OGC). Technica ...

implementation) Spatial analysis