scripts/builtin/wer.dml

#-------------------------------------------------------------
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#-------------------------------------------------------------

# This built-in function computes the word error rate (WER)
# defined as wer = (numSubst + numDel + numIns) / length(r)
#
# INPUT:
# ------------------------------------------------------------------------------
# R     Input frame of reference strings, shape: [N x 1]
# H     Input frame of hypothesis strings, shape: [N x 1]
# ------------------------------------------------------------------------------
#
# OUTPUT:
# ------------------------------------------------------------------------------
# W     Output matrix of word error rate per pair of strings,
#       shape: [N x 1], where W[i,1] = wer(R[i,1], H[i,1])
# ------------------------------------------------------------------------------

f_wer = function(Frame[String] R, Frame[String] H)
  return (Matrix[Double] W)
{
  F = cbind(R, H);
  T = map(F, "x -> new String[]{String.valueOf(UtilFunctions.getWordErrorRate(x[0], x[1])),\"\"}", margin=1);
  W = as.matrix(T[,1]);
}