PatchStat {SDMTools} | R Documentation |

`PatchStat`

calculates the patch statistics for
individual patches identified in a matrix of data. The
matrix can be a raster of class 'asc' (adehabitat package),
'RasterLayer' (raster package) or 'SpatialGridDataFrame'
(sp package).

PatchStat(mat, cellsize = 1, latlon = FALSE)

`mat` |
a matrix of data with individual patches
identified as with |

`cellsize` |
cell size (in meters) is a single value representing the width/height of cell edges (assuming square cells) |

`latlon` |
boolean value representing if the data is geographic. If latlon == TRUE, matrix must be of class 'asc', 'RasterLayer' or 'SpatialGridDataFrame' |

The patch statistics are based on statistics calculated by fragstats http://www.umass.edu/landeco/research/fragstats/fragstats.html.

a data.frame listing

`patchID` |
the unique ID for each patch. |

`n.cell` |
the number of cells for each patch, specified in square meters. |

`n.core.cell` |
the number of cells in the core area, without the edge area. |

`n.edges.perimeter` |
the number of outer perimeter cell edges of the patch. |

`n.edges.internal` |
the number of internal cell edges of the patch. |

`area` |
the area of each patch comprising a landscape mosaic. |

`core.area` |
represents the interior area of the patch, greater than the specified depth-of-edge distance from the perimeter. |

`perimeter` |
the perimeter of the patch, including any internal holes in the patch, specified in meters. |

`perim.area.ratio` |
the ratio of the patch perimeter (m) to area (m2). |

`shape.index` |
the shape complexity, sum of each patches perimeter divided by the square root of patch area. |

`frac.dim.index` |
fractal dimension index reflects shape complexity across a range of spatial scales; approaches 2 times the logarithm of patch perimeter (m) divided by the logarithm of patch area (m2). |

`core.area.index` |
quantifies core area as a percentage of patch area. |

Jeremy VanDerWal jjvanderwal@gmail.com

McGarigal, K., S. A. Cushman, M. C. Neel, and E. Ene. 2002. FRAGSTATS: Spatial Pattern Analysis Program for Categorical Maps. Computer software program produced by the authors at the University of Massachusetts, Amherst. Available at the following web site: www.umass.edu/landeco/research/fragstats/fragstats.html

#define a simple binary matrix tmat = { matrix(c( 0,0,0,1,0,0,1,1,0,1, 0,0,1,0,1,0,0,0,0,0, 0,1,NA,1,0,1,0,0,0,1, 1,0,1,1,1,0,1,0,0,1, 0,1,0,1,0,1,0,0,0,1, 0,0,1,0,1,0,0,1,1,0, 1,0,0,1,0,0,1,0,0,1, 0,1,0,0,0,1,0,0,0,1, 0,0,1,1,1,0,0,0,0,1, 1,1,1,0,0,0,0,0,0,1),nr=10,byrow=TRUE) } #do the connected component labelling ccl.mat = ConnCompLabel(tmat) ccl.mat image(t(ccl.mat[10:1,]),col=c('grey',rainbow(length(unique(ccl.mat))-1))) #calculate the patch statistics ps.data = PatchStat(ccl.mat) ps.data

[Package *SDMTools* version 1.1-221 Index]