scripts/builtin/normalizeApply.dml

#-------------------------------------------------------------
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# Min-max normalization (a.k.a. min-max scaling) to range [0,1], given 
# existing min-max ranges. For matrices of positive values, this normalization 
# preserves the input sparsity. The validity of the provided min-max range
# and post-processing is under control of the caller. 
#
# INPUT:
# ------------------------------------------------
# X     Input feature matrix of shape n-by-m
# cmin  Colunm minima of shape 1-by-m
# cmax  Column maxima of shape 1-by-m
# ------------------------------------------------
#
# OUTPUT:
# ------------------------------------------------
# Y     Modified output feature matrix of shape n-by-m
# ------------------------------------------------


m_normalizeApply = function(Matrix[Double] X, Matrix[Double] cmin, Matrix[Double] cmax)
  return (Matrix[Double] Y)
{
  # normalize features to given range ([0,1] if indeed min/max)
  Y = (X - cmin) / (cmax - cmin);
}