.TH d.correlate 1grass "" "GRASS 6.4.2" "Grass User's Manual"
.SH NAME
\fI\fBd.correlate\fR\fR  - Prints a graph of the correlation between data layers (in pairs).
.SH KEYWORDS
display, diagram
.SH SYNOPSIS
\fBd.correlate\fR
.br
\fBd.correlate help\fR
.br
\fBd.correlate layer1\fR=\fIstring\fR \fBlayer2\fR=\fIstring\fR  [\fBlayer3\fR=\fIstring\fR]   [\fBlayer4\fR=\fIstring\fR]   [--\fBverbose\fR]  [--\fBquiet\fR] 
.SS Parameters:
.IP "\fBlayer1\fR=\fIstring\fR" 4m
.br
raster input map
.IP "\fBlayer2\fR=\fIstring\fR" 4m
.br
raster input map
.IP "\fBlayer3\fR=\fIstring\fR" 4m
.br
raster input map
.IP "\fBlayer4\fR=\fIstring\fR" 4m
.br
raster input map
.PP
.SH DESCRIPTION
\fId.correlate\fR is a shell (sh(1)) script that
graphically displays the results of an
\fIr.stats\fR 
run on two raster map layers.  This shell script is useful
for highlighting the correlation (or lack of it) among data
layers (scattergram).
.PP
The results are displayed in the active display frame on
the user's graphics monitor.  \fId.correlate\fR erases
the active frame before displaying results.
.SH OPTIONS
.SS Parameters:
.IP "\fIlayer1 layer2 \fR[\fIlayer3\fR [\fIlayer4\fR]]
.br
The names of from two to four existing raster map layers
to be included in the correlation.
.PP
.SH NOTES
This is a shell script that uses 
\fIr.stats\fR 
and the UNIX \fIawk\fR command
to calculate the correlation among data layers,
and uses 
\fId.text\fR and 
\fId.graph\fR to display the results.
.PP
If three or four map layers are specified, the correlation
among each combination of two data layers is displayed.
.SH FILES
This program is simply a shell script.  Users are
encouraged to make their own shell script programs using
similar techniques.  See $GISBASE/scripts/d.correlate.
.SH SEE ALSO
The UNIX \fIawk\fR command.
.PP
\fI
d.text,
d.graph,
r.coin,
r.regression.line,
r.stats
\fR
.SH AUTHOR
Michael Shapiro,
U.S.Army Construction Engineering 
Research Laboratory
.PP
Rewritten to GRASS 6 (from csh to sh) by Markus Neteler
.PP
\fILast changed: $Date: 2011-11-08 12:29:50 +0100 (Tue, 08 Nov 2011) $\fR
.PP
Full index
.PP
© 2003-2011 GRASS Development Team