NAME

       i.spectral  - Displays spectral response at user specified locations in group or images.

KEYWORDS

       imagery, raster, multispectral

SYNOPSIS

       i.spectral
       i.spectral help
       i.spectral   [-imc]    [group=string]     [raster=string[,string,...]]     [output=string]
       [--overwrite]  [--verbose]  [--quiet]

   Flags:
       -i
           Use image list and not group

       -m
           Select multiple points

       -c
           Show pick coordinates instead of numbering in the legend

       --overwrite
           Allow output files to overwrite existing files

       --verbose
           Verbose module output

       --quiet
           Quiet module output

   Parameters:
       group=string
           Group input

       raster=string[,string,...]
           Raster input maps

       output=string
           Write output to PNG image

DESCRIPTION

       i.spectral displays spectral response at user specified locations in images.

NOTES

       This script needs gnuplot to be installed.

EXAMPLES

       Analysis of LANDSAT TM7 channels (North Carolina dataset):
       g.region rast=lsat7_2002_10 -p
       d.mon x0
       d.rast lsat7_2002_40
       i.spectral                                                                              -i
       rast=lsat7_2002_10,lsat7_2002_20,lsat7_2002_30,lsat7_2002_40,lsat7_2002_50,lsat7_2002_70
         Spectral  plot of 3 different land cover types: (1) water, (2) green vegetation, and (3)
       highway

       To analyze a time series of maps, use:
       d.rast map_1
       LIST=`g.mlist type=rast mapset=timeseries pat="map_*" | sort -t '_' -k 2 -n | tr '\n' ','|
       sed 's+,$++g'`
       i.spectral -i rast=$LIST
         This  will search all maps in the mapset 'timeseries' which match have the 'map_' prefix
       and order by a number following this prefix (day of the year etc). The user is then  asked
       to click into a map position and the resulting pixel values of all matching maps are drawn
       in the gnuplot output.

SEE ALSO

       d.what.rast
       d.where
       r.what

AUTHOR

       Markus Neteler
       Francesco Pirotti

       Last changed: $Date: 2012-08-20 03:35:34 -0700 (Mon, 20 Aug 2012) $

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       © 2003-2013 GRASS Development Team