scripts/builtin/imputeByFDApply.dml

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# Implements builtin for imputing missing values from observed values (if exist) using robust functional dependencies
#
# INPUT:
# --------------------------------------------------------------------------------------
# X          Matrix X
# source     source attribute to use for imputation and error correction
# target     attribute to be fixed
# threshold  threshold value in interval [0, 1] for robust FDs
# --------------------------------------------------------------------------------------
#
# OUTPUT:
# ---------------------------------------------------------------------------------
# X     Matrix with possible imputations
# ---------------------------------------------------------------------------------

m_imputeByFDApply = function(Matrix[Double] X, Matrix[Double] Y_imp)
  return(Matrix[Double] imputed_Y)
{
  X = replace(target = X, pattern=NaN, replacement=1)
  X = replace(target = X, pattern=0, replacement=1)
  imputed_Y = table(seq(1,nrow(X)), X, 1, nrow(X), nrow(Y_imp)) %*% Y_imp;

  if(sum(imputed_Y) == 0)
    imputed_Y = imputed_Y + NaN
  else  
    imputed_Y = replace(target=imputed_Y, pattern=0, replacement=NaN)
}