Examples with SpTree org.deeplearning4j.clustering.sptree.SpTree used on opensource projects

Example 1 with SpTree

use of org.deeplearning4j.clustering.sptree.SpTree in project deeplearning4j by deeplearning4j.

the class BarnesHutTsne method gradient.

@Override
public Gradient gradient() {
    if (yIncs == null)
        yIncs = zeros(Y.shape());
    if (gains == null)
        gains = ones(Y.shape());
    AtomicDouble sumQ = new AtomicDouble(0);
    /* Calculate gradient based on barnes hut approximation with positive and negative forces */
    INDArray posF = Nd4j.create(Y.shape());
    INDArray negF = Nd4j.create(Y.shape());
    if (tree == null)
        tree = new SpTree(Y);
    tree.computeEdgeForces(rows, cols, vals, N, posF);
    for (int n = 0; n < N; n++) tree.computeNonEdgeForces(n, theta, negF.slice(n), sumQ);
    INDArray dC = posF.subi(negF.divi(sumQ));
    Gradient ret = new DefaultGradient();
    ret.gradientForVariable().put(Y_GRAD, dC);
    return ret;
}