1r.regression.line(1) Grass User's Manual r.regression.line(1)
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6 r.regression.line - Calculates linear regression from two raster maps:
7 y = a + b*x
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10 raster, statistics
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13 r.regression.line
14 r.regression.line help
15 r.regression.line [-g] map1=string map2=string [output=string]
16 [--verbose] [--quiet]
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18 Flags:
19 -g
20 Print in shell script style
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22 --verbose
23 Verbose module output
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25 --quiet
26 Quiet module output
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28 Parameters:
29 map1=string
30 Map for x coefficient
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32 map2=string
33 Map for y coefficient
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35 output=string
36 ASCII file for storing regression coefficients (output to screen if
37 file not specified).
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40 r.regression.line Calculates linear regression from two raster maps,
41 according to the formula y = a + b*x, where x and y represent raster
42 maps. Optionally saves regression coefficients to an ASCII file. The
43 result includes the following coefficients: offset/intercept (a) and
44 gain/slope (b), residuals (R), number of elements (N), means (medX,
45 medY), standard deviations (sdX, sdY), and the F test for testing the
46 significance of the regression model as a whole (F).
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49 Comparison of the old and the new DEM in Spearfish:
50 g.region rast=elevation.10m -p
51 r.regression.line map1=elevation.dem map2=elevation.10m
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54 Using the script style flag AND eval to make results available in the
55 shell:
56 g.region rast=elevation.10m -p
57 eval `r.regression.line -g map1=elevation.dem map2=elevation.10m`
58 echo $a
59 479.615
60 echo $b
61 0.645631
62 echo $R
63 0.804441
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67 Dr. Agustin Lobo - alobo at ija.csic.es
68 Updated to GRASS 5.7 Michael Barton, Arizona State University
69 Script style output Markus Neteler
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71 Last changed: $Date: 2007-12-17 14:53:55 +0100 (Mon, 17 Dec 2007) $
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75 © 2003-2008 GRASS Development Team
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79GRASS 6.3.0 r.regression.line(1)