public void testFft2Slices() {
DComplexMatrix3D Acopy = A.copy();
((WrapperDComplexMatrix3D) A).fft2Slices();
((WrapperDComplexMatrix3D) A).ifft2Slices(true);
for (int s = 0; s < A.slices(); s++) {
for (int r = 0; r < A.rows(); r++) {
for (int c = 0; c < A.columns(); c++) {
assertEquals(Acopy.getQuick(s, r, c), A.getQuick(s, r, c), TOL);
}
}
}
}
public void compute() {
int n = A.columns();
// Distances to centroids
DoubleMatrix2D D = new DenseDoubleMatrix2D(k, n);
// Object-cluster assignments
V = new DenseDoubleMatrix2D(n, k);
// Initialize the centroids with some document vectors
U = new DenseDoubleMatrix2D(A.rows(), k);
U.assign(A.viewPart(0, 0, A.rows(), k));
int[] minIndices = new int[D.columns()];
double[] minValues = new double[D.columns()];
for (iterationsCompleted = 0; iterationsCompleted < maxIterations; iterationsCompleted++) {
// Calculate cosine distances
U.zMult(A, D, 1, 0, true, false);
V.assign(0);
U.assign(0);
// For each object
MatrixUtils.maxInColumns(D, minIndices, minValues);
for (int i = 0; i < minIndices.length; i++) {
V.setQuick(i, minIndices[i], 1);
}
// Update centroids
for (int c = 0; c < V.columns(); c++) {
// Sum
int count = 0;
for (int d = 0; d < V.rows(); d++) {
if (V.getQuick(d, c) != 0) {
count++;
U.viewColumn(c).assign(A.viewColumn(d), Functions.PLUS);
}
}
// Divide
U.viewColumn(c).assign(Mult.div(count));
MatrixUtils.normalizeColumnL2(U, null);
}
}
}
