r.rescale(1)

1r.rescale(1)                  Grass User's Manual                 r.rescale(1)
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NAME

6       r.rescale   -  Rescales  the  range  of category values in a raster map
7       layer.
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KEYWORDS

10       raster
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SYNOPSIS

13       r.rescale
14       r.rescale help
15       r.rescale [-q] input=string  [from=min,max]   output=string  to=min,max
16       [title="phrase"]   [--overwrite]
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18   Flags:
19       -q  Quietly
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21       --overwrite
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23   Parameters:
24       input=string
25           The name of the raster map to be rescaled
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27       from=min,max
28           The  input  data range to be rescaled (default: full range of input
29           map)
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31       output=string
32           The resulting raster map name
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34       to=min,max
35           The output data range
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37       title=
38           Title for new raster map
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DESCRIPTION

41       The r.rescale program rescales the range of category  values  appearing
42       in a raster map layer.  A new raster map layer, and an appropriate cat‐
43       egory file and color table based upon the original  raster  map  layer,
44       are  generated  with category labels that reflect the original category
45       values that produced each category.  This command is useful for produc‐
46       ing  representations  with a reduced number of categories from a raster
47       map layer with a large range  of  category  values  (e.g.,  elevation).
48       Rescaled  map  layers are appropriate for use in such GRASS programs as
49       r.stats, r.report, and r.coin.
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EXAMPLE

52       To rescale an elevation raster map layer with category  values  ranging
53       from  1090  meters  to  1800 meters into the range 0-255, the following
54       command line could be used:  r.rescale  input=elevation  from=1090,1800
55       output=elevation.255 to=0,255
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NOTES

58       Category  values  that  fall  beyond  the input range will become NULL.
59       This allows the user to select a subset  of  the  full  category  value
60       range  for  rescaling if desired.  This also means that the user should
61       know the category value range for the input raster map layer.  The user
62       can  request  the  r.rescale  program  to  determine this range, or can
63       obtain it using the r.info command.  If the  category  value  range  is
64       determined using r.rescale, the input raster map layer is examined, and
65       the minimum and maximum non-NULL category values are  selected  as  the
66       input range.
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AUTHOR

73       Michael Shapiro, U.S.Army Construction Engineering Research Laboratory
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75       Last changed: $Date: 2003/05/06 15:25:31 $
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77       Full index
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81GRASS 6.2.2                                                       r.rescale(1)