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NAME

r.regression.line - Calculates linear regression from two raster maps: y = a + b*x

KEYWORDS

raster, statistics

SYNOPSIS

r.regression.line
r.regression.line help
r.regression.line map1=string map2=string [output=string]

Parameters:

map1=string
Map for x coefficient
map2=string
Map for y coefficient
output=string
ASCII file for storing regression coefficients (output to screen if file not specified).

DESCRIPTION

r.regression.line Calculates linear regression from two raster maps, according to the formula y = a + b*x, where x and y represent raster maps. Optionally saves regression coefficients to an ASCII file. The result includes the following coefficients: offset (a) and gain (b), residuals (R), number of elements (N), medians (medX, medY), standard deviations (sdX, sdY), and the F test for testing the significance of the regression model as a whole (F).

EXAMPLE

Comparison of the old and the new DEM in Spearfish:
g.region rast=elevation.10m -p
r.regression.line map1=elevation.dem map2=elevation.10m

AUTHOR

Dr. Agustin Lobo - alobo at ija.csic.es
Updated to GRASS 5.7 Michael Barton, Arizona State University

Last changed: $Date: 2007/12/04 20:44:26 $


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