#-------------------------------------------------------------
#
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.
#
#-------------------------------------------------------------

# frequency code apply
#
# INPUT:
# -------------------------------------------------------------------------------------
# X          dataset x
# freqCount  the frequency counts for the different categoricals
# -------------------------------------------------------------------------------------
#
# OUTPUT:
# -----------------------------------------------------------------------------------------
# X          categorical columns are replaced with their frequencies given
# -----------------------------------------------------------------------------------------


m_frequencyEncodeApply = function(Matrix[Double] X, Matrix[Double] freqCount)
return (Matrix[Double] X) {

 parfor(i in 1:ncol(X))
  {
    if(sum(freqCount[i]) > 0)
    {
      Y = replace(target=X[, i], pattern=NaN, replacement=1)
      idx = min(ncol(freqCount), max(Y))
      valueCount = freqCount[i, 1:idx]
      resp = matrix(0, nrow(Y), idx)
      resp = (resp + t(seq(1, idx))) == Y
      resp = resp * valueCount
      X[, i] = rowSums(resp)
    }
  }
}
