scripts/builtin/scaleMinMax.dml

#-------------------------------------------------------------
#
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# to you under the Apache License, Version 2.0 (the
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#-------------------------------------------------------------

# This function performs min-max normalization (rescaling to [0,1]).
# 
# This function is deprecated, use normalize instead.
#
# INPUT:
# ---------------------------------------------
# X      Input feature matrix
# ---------------------------------------------
#
# OUTPUT:
# --------------------------------------------
# Y      Scaled output matrix
# --------------------------------------------

m_scaleMinMax = function(Matrix[Double] X)
  return (Matrix[Double] Y)
{
  print("Deprecated scaleMinMax use normalize instead")
  # compute feature ranges for transformations
  cmin = colMins(X);
  cmax = colMaxs(X);
  diff = (cmax - cmin)
  # avoid division by zero and divide by 1 instead
  diff = replace(target=diff, pattern=0, replacement=1);
  # normalize features to given range ([0,1] if indeed min/max)
  Y = (X - cmin) / diff;
}