i.pca(1) - f14

1i.pca(1)                      Grass User's Manual                     i.pca(1)
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NAME

6       i.pca  - Principal components analysis (pca) program for image process‐
7       ing.
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KEYWORDS

10       imagery
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SYNOPSIS

13       i.pca
14       i.pca help
15       i.pca input=name[,name,...] output=name   [rescale=min,max]    [--over‐
16       write]  [--verbose]  [--quiet]
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18   Flags:
19       --overwrite
20           Allow output files to overwrite existing files
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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       input=name[,name,...]
30           Name of input raster map(s)
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32       output=name
33           Name for output raster map
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35       rescale=min,max
36           Rescaling range output (For no rescaling use 0,0)
37           Default: 0,255
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DESCRIPTION

40       i.pca is an image processing program based on the algorithm provided by
41       Vali (1990), that processes n (2 >= n) input raster map layers and pro‐
42       duces n output raster map layers containing the principal components of
43       the input data in decreasing order of variance ("contrast").  The  out‐
44       put  raster map layers are assigned names with .1, .2, ... .n suffixes.
45       The  current  geographic  region  definition  and  mask  settings   are
46       respected  when  reading  the input raster map layers. When the rescale
47       option is used, the output files are rescaled to fit the min,max range.
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OPTIONS

50   Parameters:
51       input=name,name[,name,name,...]
52              Name of two or more input raster map layers.
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54       output=name
55              The output raster map layer name to which  suffixes  are  added.
56              Each  output  raster  map  layer is assigned this user-specified
57              name with a numerical (.1, .2, ...
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59       rescale=min,max
60              The  optional  output  category  range.  (Default:   0,255)   If
61              rescale=0,0,  no rescaling is performed on output files.
62              If  output  is rescaled, the output raster will be of type CELL.
63              If the output is not rescaled, the output raster will be of type
64              DCELL.
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NOTES

67       Richards  (1986)  gives  a good example of the application of principal
68       components analysis (pca) to a time  series  of  LANDSAT  images  of  a
69       burned region in Australia.
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AUTHOR

87       David Satnik, GIS Laboratory
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89       Major modifications for GRASS 4.1 were made by
90       Olga Waupotitsch and Michael Shapiro, U.S.Army Construction Engineering
91       Research Laboratory
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93       Rewritten for GRASS 6.x and major modifications by
94       Brad Douglas
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96       Last changed: $Date: 2007-02-19 23:55:56 +0100 (Mon, 19 Feb 2007) $
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98       Full index
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100       © 2003-2008 GRASS Development Team
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104GRASS 6.3.0                                                           i.pca(1)