Tools

Tool name * PATHMATRIX
Description

PATHMATRIX is a tool to compute matrices of effective geographic distances among samples, based on a least-cost path algorithm. Punctual locations (points) or zones encompassing sample data points (polygons) are used in conjunction with a species-specific friction map representing the cost of movement through the landscape. Three different types of distances can be computed.

  1. least-cost distance,
  2. length of the least-cost path,
  3. Euclidean distance.

Matrices of effective distances can then be exported to other software to test, for example, for isolation by distance. The use of effective distances allows to investigate the role of the environment on the spatial genetic structuring of populations. Especially for habitat specialists, least-cost distances may give a more realistic measure of spatial isolation (or its inverse, connectivity) than standard Euclidean distance (e.g. Chardon et al. 2003; Coulon et al. 2004) PATHMATRIX is an extension to the Geographical Information System (GIS) software ARCVIEW 3.x, and is written in the language Avenue. It needs to be used in conjunction with the ARCVIEW module Spatial Analyst.

Category All, Data, Mapping
What step(s) in analysis framework 1a, 2a
What step(s) in Governance framework
inputs

Sample coordinates can either be described through an existing point shapefile displayed in the current View, or through a simple (text) coordinates file in SPLATCHE format (Currat M et al. 2004). If an existing point shapefile is used, it MUST have an 'Id' field (numbers or strings) with unique identifiers.

Data Quality Required

Modification Required

Not available

Expertise Required

GIS

Spatial and Temporal

Not available

Outputs

Excel, text formats

License cost issues

No, but ArcGIS/ArcView is not free and a license has to be purchased from Esri

Download
Literature: References & Manuals *

http://cmpg.unibe.ch/software/pathmatrix/index.htm

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