Note: This document is for an older version of GRASS GIS that is outdated. You should upgrade, and read the current manual page.

NAME

KEYWORDS

SYNOPSIS

DESCRIPTION

Analysis methods

• Whole map layer: entire map (current region),
• Keyboard setting: based on keyboard selection for region definition,
• Draw the sampling frame: based on interactive region selection via mouse.

• Whole map layer: use entire area selected above,
• Regions: select one to many subareas via mouse,
• Sample units: automated selection of sampling area (for details see below)
• Random nonoverlapping,
• Systematic contiguous,
• Systematic noncontiguous,
• Stratified random,
• Centered over sites (vector points).
• Moving window: rectangular or circular with size
• Select areas from the overlaid vector map (for details see below)

Usage details

1. Load a file: the configuration is printed using rectangles with differents colors (green for the raster map, red for the sample frame and blue for the sample areas), and other notes (disposition of sample areas etc). The configuration file is saved in ~/.r.li/history/my_conf (the file name can be defined by the user). The output can either be a new raster map (in case of using a "moving window" analysis) or be an ASCII text file (when not performing a "moving window" analysis) containing the result which is then saved to the folder $HOME/.r.li/output/.
   All dimensions are percentages of raster rows or columns.
2. Create a new file: this create a new configuration file in an interactive way, in three steps:
1. Choose file name and maps to use for setting:
• Configuration file name (required): the name of new configuration file
• Raster map name to use to select areas (required): the name of raster map to use for setting
• Vector areas map to overlay (optional): name of a vector map to overlay in setting
• Vector points map to overlay (optional): name of vector map of points type to overlay in setting
2. Set the sampling frame. The sample frame is a rectangular area which contains all the areas to analyze. It can be defined in three ways:
• Whole map layer: the sample frame is the whole map
• Keyboard setting: the user enters the coordinates in cells of upper left corner of sampling frame and its length in rows and columns.
• Draw the sample frame: the user draws the sample frame on map using mouse.
3. Set the sample areas. The sample areas are simply the areas to analyze. They can be defined in five ways (see the picture below):
• Whole map layer: the sample area is the whole sample frame
• Regions: the user enters the number of areas and then draws them using mouse.
• Sample units: they are areas of rectangular or circular shape. The user can define them using keyboard or mouse.
• keyboard: the user define the shape of sample unists and their disposition:
• Random non overlapping: the user specifies the number of sample units and they are placed in a random way at runtime. It is guaranteed that the areas do not intersect themselves.
• Systematic contiguous: the defined sample is placed covering the sample frame, side by side across rows.
• Systematic non contiguous: the same as above, but here ever rectangle is spaced from another by a specified number of cells.
• Stratified random: the sample frame is divided in n strats of rows and m strats of columns (n and m are given by user), then the specified number of sample areas are placed in a random way, one for every m*n areas defined by strats.
• Centered over sites: the sample areas are placed into sample frame centering them on points in site file.
• mouse: the user chooses the shape and then draws the specified number of sample areas on map.
• Moving Window: the user defines a rectangular or circular area, it is moved over all the raster increasing only of a cell for every move(in columns if possible, if not in rows). It produces a new raster containing the result of all analysis.
• Select areas from the overlaid vector map: the sample areas are defined by the vector map selected above. For every cat in vector map, the procedure prompts the user if he wants to include it as sample area. The resulting configuration file can be used only with the specified raster map, and the procedure can be used only if whole map layer is selected as sampling frame.
3. Remove a file the selected file is deleted from the available configuration files.
4. Help: open this help text.
5. Close module window.

NOTES

EXAMPLES

Moving window analysis on full region

Click on "New", then:

• Configuration file name: "movwindow7"
• Raster map name to use to select areas: "forests"

• Define a sampling frame (region for analysis): "Whole map layer", then "OK"

• Define sampling areas: "Moving window", then "OK"
• Then click on "Use keyboard to define moving window dimension"

• [x] Rectangular
• Width size (in cells)?: "7"
• Height size (in cells)?: "7"
• Then "Save settings"

Now an anaysis can be performed using one of the analytical modules, e.g.

g.region rast=forests -p
r.li.patchdensity map=forests conf=movwindow7 output=forests_p_dens7
r.univar forests_p_dens7

Whole region analysis

• Configuration file name: "whole_region"
• Raster map name to use to select areas: "lsat7_2000_40"

• Define a sampling frame (region for analysis): "Whole map layer", then "OK"

• Define sampling areas: "Whole map layer", then "OK"

Now an anaysis can be performed using one of the analytical modules, e.g.

g.region rast=lsat7_2002_40 -p
r.li.shannon map=lsat7_2000_40 conf=whole_region output=lsat7_2000_40_shannon

SEE ALSO

Old r.le suite manual

REFERENCES

AUTHORS

Last changed: $Date: 2014-02-11 08:24:44 -0800 (Tue, 11 Feb 2014) $

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