scripts/utils/cbind.dml

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# Utility script to append 1 matrix to another and apply row range
# indexing. This is used for R cbind() like functionality returning
# the head() of the result.
#
# Parameters:
#    x    : (input) 1st data set
#    y    : (input) 2nd data set
#    n    : (input) number of rows to return, i.e.: 1:n
#    o    : (output) 
#    ofmt : (default "csv"); format of output
#
# Example:
#   hadoop jar SystemML.jar -f algorithms/utils/cbind.dml -nvargs x="/tmp/M.mtx" y="/tmp/M1.mtx" n=100 o="/tmp/o.mtx"
#

ofmt = ifdef ($ofmt, "csv");

x = read ($x);
y = read ($y);

if ($n == nrow(x))
{

   xp = x;
   yp = y;
} 
else 
{
   xp = x[1:$n,];
   yp = y[1:$n,];
}

o = append (xp, yp);

write (o, $o, format=ofmt);