DESCRIPTION
r.pi.enn computes the euclidean distance between patches (1-n NN).
Analysis of n-th euclidean nearest neighbour distance.
NOTES
The user must specify the names of the raster map layers to
be used for input and output, the keyval the
method (e.g. distance, area) and statmethod used (i.e.,
average).
Within r.pi.enn the following setting have to be set:
keyval setting:
The keyval operator determines which category value is taken for the Patch Index analysis.
Method setting:
The method operators determine what measure is applied
on the nth NN.
- Distance
- The Average computes the average distance of the n NN.
- Path distance
- The path_distance computes the actual distance to the n NN.
- Area
- The area computes the area of the n NN.
- Perimeter
- The perimeter computes the perimeter of the n NN.
- SHAPE Index
- The shapeindex computes the SHAPE Index of the n NN.
Statmethod setting:
The statmethod operators determine what statistic measure is applied
on the nth NN.
- Average
- The Average computes the average distance of the n NN.
- Variance
- The Variance computes the variance of the distance of the n NN.
- Std. Dev.
- The Std. Dev computes the std. dev. of the distance of the n NN.
Number:
The keyval operator determines which or how many Nearest Neighbour are analysed.
1,2,5 will analyse the 1, 2 and 5th Nearest Neigbour.
1-10 will analyse the 1, 2, 3, ... 10th Nearest Neighbour.
0 will analyse all Nearest Neighbours.
Distancematrix:
The dmout operator is optional and determines if a distance matrix is written (first NN only).
1,2,5 will analyse the 1, 2 and 5th Nearest Neigbour.
1-10 will analyse the 1, 2, 3, ... 10th Nearest Neighbour.
0 will analyse all Nearest Neighbours.
EXAMPLE
An example for the North Carolina sample dataset:
r.pi.enn input=landclass96 output=dist1.c5 keyval=5 method=distance number=1 statmethod=average
# -> gives a map of patches (all of category of 5) with the average distance to their first NN
r.pi.enn input=landclass96 output=dist10.c5 keyval=5 method=distance number=10 statmethod=average
# -> gives a map of patches (all of category of 5) with the average distance to their first-10th NN
r.pi.enn input=landclass96 output=dist1.5.10.c5 keyval=5 method=distance number=1,5,10 statmethod=average
# -> gives a map of patches (all of category of 5) with the average distance to their first, first-to-fifth and first-to-10th NN
r.pi.enn input=landclass96 output=dist10b.c5 keyval=5 method=path_distance number=10 statmethod=average
# -> gives a map of patches (all of category of 5) with the actual distance to the 10th NN
SEE ALSO
r.pi.index,
r.fragment.dist,
r.pi.enn,
r.pi.enn.pr,
r.fragment.neighbors,
r.li
AUTHORS
Programming: Elshad Shirinov
Scientific concept: Dr. Martin Wegmann
Department of Remote Sensing
Remote Sensing and Biodiversity Unit
University of Wuerzburg, Germany
Port to GRASS GIS 7: Markus Metz
Last changed: $Date$