content: /*
   * Tencent is pleased to support the open source community by making Angel available.
   *
   * Copyright (C) 2017-2018 THL A29 Limited, a Tencent company. All rights reserved.
   *
   * Licensed 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
   *
   * https://opensource.org/licenses/Apache-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.
   *
   */
  
  package com.tencent.angel.spark.ml.psf.ftrl;
  
  import com.tencent.angel.ml.math2.ufuncs.Ufuncs;
  import com.tencent.angel.ml.math2.vector.Vector;
  import com.tencent.angel.ml.matrix.psf.update.base.PartitionUpdateParam;
  import com.tencent.angel.ml.matrix.psf.update.enhance.MultiRowUpdateFunc;
  import com.tencent.angel.ml.matrix.psf.update.enhance.MultiRowUpdateParam.MultiRowPartitionUpdateParam;
  import com.tencent.angel.ps.storage.partition.RowBasedPartition;
  import com.tencent.angel.ps.storage.vector.ServerRow;
  import com.tencent.angel.ps.storage.vector.ServerRowUtils;
  
  public class ComputeW extends MultiRowUpdateFunc {
  
    public ComputeW(int matrixId, int[] rowIds, double[][] values) {
      super(matrixId, rowIds, values);
    }
  
    public ComputeW(int matrixId, double alpha, double beta, double lambda1, double lambda2, double offset) {
      this(matrixId, new int[]{0, 1, 2}, new double[][]{{alpha, beta, lambda1, lambda2}, {offset}});
    }
  
    public ComputeW() {}
  
    @Override
    public void partitionUpdate(PartitionUpdateParam partParam) {
      if (partParam instanceof MultiRowPartitionUpdateParam) {
        MultiRowPartitionUpdateParam param = (MultiRowPartitionUpdateParam) partParam;
        int[] rowIds = param.getRowIds();
        double[][] values = param.getValues();
        double alpha = values[0][0];
        double beta  = values[0][1];
        double lambda1 = values[0][2];
        double lambda2 = values[0][3];
  
        int offset = (int) values[1][0];
  
        RowBasedPartition part = (RowBasedPartition) psContext.getMatrixStorageManager().getPart(param.getPartKey());
        for (int i = 0; i < offset; i++) {
          Vector z = ServerRowUtils.getVector(part.getRow(rowIds[0]*offset + i));
          Vector n = ServerRowUtils.getVector(part.getRow(rowIds[1]*offset + i));
          Vector w = Ufuncs.ftrlthreshold(z, n, alpha, beta, lambda1, lambda2);
          ServerRowUtils.setVector(part.getRow(rowIds[2]*offset + i), w.ifilter(1e-11));
        }
  //      // calculate bias
  //      if (param.getPartKey().getStartCol() <= 0 && param.getPartKey().getEndCol() > 0) {
  //        double zVal = VectorUtils.getDouble(z, 0);
  //        double nVal = VectorUtils.getDouble(n, 0);
  //        VectorUtils.setFloat(w, 0, (float) (-1.0 * alpha * zVal / (beta + Math.sqrt(nVal))));
  //      }
      }
    }
  
    @Override
    public void update(ServerRow row, double[] values) {
      // Do nothing.
    }
  }
  