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#
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# Utility script to shuffle input dataset
#
# Parameters:
#    x    : (input) data set
#    o    : (output) 
#    ofmt : (default "csv") format of output
#
# Example:
#   hadoop jar SystemDS.jar -f algorithms/utils/shuffle.dml -nvargs x="/tmp/M.mtx" o="/tmp/o.mtx"
#

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

x = read ($x);
num_col = ncol(x)
# Random vector used to shuffle the dataset
y = rand(rows=nrow(x), cols=1, min=0, max=1, pdf="uniform")
x = order(target = cbind(x, y), by = num_col + 1)
o = x[,1:num_col]

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