How to use

getColumnCount

method

in

de.jungblut.math.DoubleMatrix

public ConditionalLikelihoodCostFunction(DoubleMatrix features,
                     DoubleMatrix outcome) {
  this.features = features;
  this.outcome = outcome;
  this.m = outcome.getRowCount();
  this.classes = outcome.getColumnCount() == 1 ? 2 : outcome.getColumnCount();
}

static DoubleMatrix binarize(Random r, DoubleMatrix hiddenActivations) {
  for (int i = 0; i < hiddenActivations.getRowCount(); i++) {
    for (int j = 0; j < hiddenActivations.getColumnCount(); j++) {
      hiddenActivations.set(i, j,
          hiddenActivations.get(i, j) > r.nextDouble() ? 1d : 0d);
    }
  }
  return hiddenActivations;
}

protected DoubleMatrix newInstance(DoubleMatrix mat) {
  if (mat.isSparse()) {
    return new SparseDoubleRowMatrix(mat.getRowCount(), mat.getColumnCount());
  } else {
    return new DenseDoubleMatrix(mat.getRowCount(), mat.getColumnCount());
  }
}

/**
 * Folds a single matrix into a single vector by rows.
 */
public static DoubleVector foldMatrix(DoubleMatrix mat) {
  DoubleVector vec = new DenseDoubleVector(mat.getRowCount()
      * mat.getColumnCount());
  int index = 0;
  for (int i = 0; i < mat.getRowCount(); i++) {
    for (int j = 0; j < mat.getColumnCount(); j++) {
      vec.set(index++, mat.get(i, j));
    }
  }
  return vec;
}

/**
 * Row-copies the given matrix to this sparse implementation.
 * 
 * @param mat the matrix to copy.
 */
public SparseDoubleRowMatrix(DoubleMatrix mat) {
 this(mat.getRowCount(), mat.getColumnCount());
 for (int i = 0; i < numColumns; i++) {
  setRowVector(i, mat.getRowVector(i));
 }
}

/**
 * Sets the weights in the whole matrix uniformly between -eInit and eInit
 * (eInit is the standard deviation) with zero mean.
 */
private void setWeightsUniformly(RandomDataImpl rnd, double eInit) {
  for (int i = 0; i < weights.getColumnCount(); i++) {
    for (int j = 0; j < weights.getRowCount(); j++) {
      weights.set(j, i, rnd.nextUniform(-eInit, eInit));
    }
  }
}

/**
 * Folds the given matrices column-wise into a single vector.
 */
public static DoubleVector foldMatrices(DoubleMatrix... matrices) {
  int length = 0;
  for (DoubleMatrix matrix : matrices) {
    length += matrix.getRowCount() * matrix.getColumnCount();
  }
  DenseDoubleVector v = new DenseDoubleVector(length);
  int index = 0;
  for (DoubleMatrix matrix : matrices) {
    for (int j = 0; j < matrix.getColumnCount(); j++) {
      for (int i = 0; i < matrix.getRowCount(); i++) {
        v.set(index++, matrix.get(i, j));
      }
    }
  }
  return v;
}

@Override
public double calculateLoss(DoubleMatrix y, DoubleMatrix hypothesis) {
  double sum = 0d;
  for (int col = 0; col < y.getColumnCount(); col++) {
    for (int row = 0; row < y.getRowCount(); row++) {
      double diff = y.get(row, col) - hypothesis.get(row, col);
      sum += (diff * diff);
    }
  }
  return sum / y.getRowCount();
}

public static double calculateRegularization(DoubleMatrix[] thetas,
                       final int m, NetworkConfiguration conf) {
  double regularization = 0d;
  // only calculate the regularization term if lambda is not 0
  if (conf.lambda != 0d) {
    for (DoubleMatrix theta : thetas) {
      regularization += (theta.slice(0, theta.getRowCount(), 1,
          theta.getColumnCount())).pow(2).sum();
    }
    regularization = (conf.lambda / (2.0d * m)) * regularization;
  }
  return regularization;
}

/**
 * Creates a new matrix with the given vector into the first column and the
 * other matrix to the other columns. This is usually used in machine learning
 * algorithms that add a bias on the zero-index column.
 * 
 * @param first the new first column.
 * @param otherMatrix the other matrix to set on from the second column.
 */
public SparseDoubleRowMatrix(DenseDoubleVector first, DoubleMatrix otherMatrix) {
 this(otherMatrix.getRowCount(), otherMatrix.getColumnCount() + 1);
 setColumnVector(0, first);
 for (int i = 1; i < numColumns; i++) {
  setColumnVector(i, otherMatrix.getColumnVector(i - 1));
 }
}

@Override
public DoubleMatrix multiply(DoubleMatrix other) {
 DoubleMatrix result = new SparseDoubleRowMatrix(this.getRowCount(),
   other.getColumnCount());
 for (int row = 0; row < getRowCount(); row++) {
  for (int col = 0; col < other.getColumnCount(); col++) {
   double sum = 0;
   Iterator<DoubleVectorElement> kIterator = getRowVector(row)
     .iterateNonZero();
   while (kIterator.hasNext()) {
    DoubleVectorElement k = kIterator.next();
    double val = other.get(k.getIndex(), col);
    if (val != 0d) {
     sum += k.getValue() * val;
    }
   }
   result.set(row, col, sum);
  }
 }
 return result;
}

@Override
public double calculateLoss(DoubleMatrix y, DoubleMatrix hypothesis) {
  double sum = 0d;
  for (int col = 0; col < y.getColumnCount(); col++) {
    for (int row = 0; row < y.getRowCount(); row++) {
      sum += FastMath.abs(y.get(row, col) - hypothesis.get(row, col));
    }
  }
  return sum / y.getRowCount();
}

/**
 * Creates a new matrix with the given vector into the first column and the
 * other matrix to the other columns. This is usually used in machine learning
 * algorithms that add a bias on the zero-index column.
 * 
 * @param first the new first column.
 * @param otherMatrix the other matrix to set on from the second column.
 */
public DenseDoubleMatrix(DenseDoubleVector first, DoubleMatrix otherMatrix) {
 this(otherMatrix.getRowCount(), otherMatrix.getColumnCount() + 1);
 // copy the first column
 System.arraycopy(first.toArray(), 0, matrix, 0, first.getDimension());
 int offset = first.getDimension();
 for (int col : otherMatrix.columnIndices()) {
  double[] clv = otherMatrix.getColumnVector(col).toArray();
  System.arraycopy(clv, 0, matrix, offset, clv.length);
  offset += clv.length;
 }
}

@Override
public DoubleMatrix multiply(DoubleMatrix other) {
 int m = this.numRows;
 int n = this.numColumns;
 int p = other.getColumnCount();
 DenseDoubleMatrix matrix = new DenseDoubleMatrix(m, p);
 for (int k = 0; k < n; k++) {
  for (int i = 0; i < m; i++) {
   for (int j = 0; j < p; j++) {
    matrix.set(i, j, matrix.get(i, j) + get(i, k) * other.get(k, j));
   }
  }
 }
 return matrix;
}

@Override
public DoubleMatrix subtract(DoubleMatrix other) {
 SparseDoubleRowMatrix result = new SparseDoubleRowMatrix(
   other.getRowCount(), other.getColumnCount());
 for (int row : this.matrix.keys()) {
  Iterator<DoubleVectorElement> iterate = matrix.get(row).iterate();
  while (iterate.hasNext()) {
   DoubleVectorElement e = iterate.next();
   result.set(row, e.getIndex(),
     e.getValue() - other.get(row, e.getIndex()));
  }
 }
 return result;
}

@Override
public DoubleMatrix add(DoubleMatrix other) {
 SparseDoubleRowMatrix result = new SparseDoubleRowMatrix(
   other.getRowCount(), other.getColumnCount());
 for (int row : this.matrix.keys()) {
  Iterator<DoubleVectorElement> iterate = matrix.get(row).iterate();
  while (iterate.hasNext()) {
   DoubleVectorElement e = iterate.next();
   result.set(row, e.getIndex(),
     e.getValue() + other.get(row, e.getIndex()));
  }
 }
 return result;
}

public static DoubleMatrix[] backwardPropagate(DoubleMatrix y,
                        DoubleMatrix[] thetas, DoubleMatrix[] ax, DoubleMatrix[] zx,
                        NetworkConfiguration conf) {
  // now backpropagate the error backwards by calculating the deltas.
  // also here we are following the math equations and nulling out the 0th
  // entry.
  DoubleMatrix[] deltaX = new DoubleMatrix[conf.layerSizes.length];
  // set the last delta to the difference of outcome and prediction
  deltaX[deltaX.length - 1] = ax[conf.layerSizes.length - 1].subtract(y);
  // compute the deltas onto the input layer
  for (int i = (conf.layerSizes.length - 2); i > 0; i--) {
    DoubleMatrix slice = thetas[i].slice(0, thetas[i].getRowCount(), 1,
        thetas[i].getColumnCount());
    deltaX[i] = multiply(deltaX[i + 1], slice, false, false, conf);
    // apply the gradient of the activations
    deltaX[i] = deltaX[i].multiplyElementWise(conf.activations[i]
        .gradient(zx[i]));
  }
  return deltaX;
}

/**
 * Creates a weight matrix that can be used for unsupervised weight
 * initialization in the {@link MultilayerPerceptron}.
 *
 * @param outputLayerSize the size of the classification layer on top of this
 *                        RBM.
 * @return the {@link WeightMatrix} that maps layers to the weights.
 */
public WeightMatrix[] getNeuralNetworkWeights(int outputLayerSize) {
  WeightMatrix[] toReturn = new WeightMatrix[this.weights.length + 1];
  // translate the matrices
  for (int i = 0; i < weights.length; i++) {
    toReturn[i] = new WeightMatrix(this.weights[i].slice(1,
        weights[i].getRowCount(), 0, weights[i].getColumnCount()));
  }
  // add a last layer on top of it
  toReturn[toReturn.length - 1] = new WeightMatrix(
      toReturn[toReturn.length - 2].getWeights().getRowCount(),
      outputLayerSize);
  return toReturn;
}

/**
 * @return a log'd matrix that was guarded against edge cases of the
 * logarithm.
 */
public static DoubleMatrix logMatrix(DoubleMatrix input) {
  DenseDoubleMatrix log = new DenseDoubleMatrix(input.getRowCount(),
      input.getColumnCount());
  for (int row = 0; row < log.getRowCount(); row++) {
    for (int col = 0; col < log.getColumnCount(); col++) {
      double d = input.get(row, col);
      log.set(row, col, guardedLogarithm(d));
    }
  }
  return log;
}

@Override
public DoubleMatrix gradient(DoubleMatrix matrix) {
  DoubleMatrix newInstance = newInstance(matrix);
  if (matrix.isSparse()) {
    // if we have a sparse matrix, it is more efficient to loop over the
    // sparse column vectors
    int[] columnIndices = matrix.columnIndices();
    for (int col : columnIndices) {
      newInstance.setColumnVector(col, gradient(matrix.getColumnVector(col)));
    }
  } else {
    // on dense matrices we can be faster by directly looping over the items
    for (int i = 0; i < matrix.getRowCount(); i++) {
      for (int j = 0; j < matrix.getColumnCount(); j++) {
        newInstance.set(i, j, gradient(matrix.get(i, j)));
      }
    }
  }
  return newInstance;
}