scripts/utils/head.dml

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# Utility script to return head, i.e. 1:n rows, from input data.
#
# Parameters:
#    x    : (input) 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/head.dml -nvargs x="/tmp/M.mtx" n=100 o="/tmp/o.mtx"
#

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

x = read ($x);

o = x[1:$n,];

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