com.expleague.ml.models.FMModel Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of jmll

Various ML methods implemented by myself and my students

There is a newer version: 1.4.9

package com.expleague.ml.models;

import com.expleague.commons.math.vectors.Mx;
import com.expleague.commons.math.vectors.Vec;
import com.expleague.commons.math.vectors.VecIterator;
import com.expleague.commons.math.vectors.impl.vectors.SparseVec;
import com.expleague.commons.math.FuncC1;
import sun.reflect.generics.reflectiveObjects.NotImplementedException;

/**
 * User: qdeee
 * Date: 17.03.14
 */
public class FMModel extends FuncC1.Stub {
  private final Mx V;  //[k x p]
  private final Vec w;
  private final double w0;

  public FMModel(final Mx v, final Vec w, final double w0) {
    V = v;
    this.w = w;
    this.w0 = w0;
  }

  public FMModel(final Mx v, final Vec w) {
    this(v, w, 0.);
  }

  public FMModel(final Mx v) {
    this(v, new SparseVec(v.columns()), 0.);
  }

  public Mx getV() {
    return V;
  }

  public Vec getW() {
    return w;
  }

  public double getW0() {
    return w0;
  }

  @Override
  public Vec gradient(final Vec x) {
    throw new NotImplementedException();
  }

  @Override
  public double value(final Vec x) {
    assert(x.dim() != V.columns());
    double value = w0;
    final VecIterator iter = x.nonZeroes();
    while (iter.advance()) {
      value += iter.value() * w.get(iter.index());
    }

    for (int k = 0; k < V.rows(); k++) {
      double sum = 0.;
      double sumSqr = 0.;
      final VecIterator i = x.nonZeroes();
      final Vec row = V.row(k);
      while (i.advance()) {
        final double d = row.get(i.index()) * i.value();
        sum += d;
        sumSqr += d * d;
      }
      value += 0.5 * (sum * sum - sumSqr);
    }
    return value;
  }

  @Override
  public int dim() {
    return w.dim();
  }

  @Override
  public boolean equals(final Object o) {
    if (this == o) return true;
    if (o == null || getClass() != o.getClass()) return false;

    final FMModel fmModel = (FMModel) o;

    if (Double.compare(fmModel.w0, w0) != 0) return false;
    if (!V.equals(fmModel.V)) return false;
    if (!w.equals(fmModel.w)) return false;

    return true;
  }

  @Override
  public int hashCode() {
    int result;
    final long temp;
    result = V.hashCode();
    result = 31 * result + w.hashCode();
    temp = Double.doubleToLongBits(w0);
    result = 31 * result + (int) (temp ^ (temp >>> 32));
    return result;
  }
}