.help binpairs Oct84 noao.nproto
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NAME
binpairs -- Bin pairs of (x,y) points in log separation
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USAGE	
binpairs file1 file2 rmin rmax nbins
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PARAMETERS
.ls file1
File containing (x,y) points to be paired.
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.ls file2
File containing (x,y) points to be paired.  This file may be the same
as file1.
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.ls rmin
The minimum separation to be binned.
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.ls rmax
The maximum separation to be binned.
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.ls nbins
The number of log separation bins to be computed.
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.ls verbose = no
Print progress information?
.le
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DESCRIPTION
The (x,y) points in the specified files are paired and the number of pairs
in each bin of log separation is computed and output.  The two files may
be the same.  There are
\fInbins\fR separation bins between the separations \fIrmin\fR and \fIrmax\fR.
If the verbose parameter is yes then progress information is printed on the
standard error output at intervals of 5% of the time.
The output consists of the lower limit of the separation bin, the number of
pairs in the bin, the number of pairs divided by the total number of pairs,
and the annular area of the bin.

This task is useful for computing two point correlation functions.
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EXAMPLES

.nf
    cl> binpairs data1 data2 .01 1 20 >> result

	    or

    cl> binpairs data data .01 1 20 >> result
.fi
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SEE ALSO
.endhelp