static IndexMappingProvider createPort(IndexMappingProvider opu, Tensor from, Tensor to) {
if (from.hashCode() != to.hashCode()) return IndexMappingProvider.Util.EMPTY_PROVIDER;
if (from.getClass() != to.getClass()) {
Tensor nonComplex;
// Processing case -2*(1/2)*g_mn -> g_mn
if (from instanceof Product && !(to instanceof Product)) {
if (from.size() != 2) return IndexMappingProvider.Util.EMPTY_PROVIDER;
if ((nonComplex = extractNonComplexFactor(from)) != null)
return new MinusIndexMappingProviderWrapper(createPort(opu, nonComplex, to));
return IndexMappingProvider.Util.EMPTY_PROVIDER;
}
// Processing case g_mn -> -2*(1/2)*g_mn
if (to instanceof Product && !(from instanceof Product)) {
if (to.size() != 2) return IndexMappingProvider.Util.EMPTY_PROVIDER;
if ((nonComplex = extractNonComplexFactor(to)) != null)
return new MinusIndexMappingProviderWrapper(createPort(opu, from, nonComplex));
return IndexMappingProvider.Util.EMPTY_PROVIDER;
}
return IndexMappingProvider.Util.EMPTY_PROVIDER;
}
IndexMappingProviderFactory factory = map.get(from.getClass());
if (factory == null) throw new RuntimeException("Unsupported tensor type: " + from.getClass());
return factory.create(opu, from, to);
}
public static Tensor symmetrize(SimpleTensor tensor, int[] freeIndices, Symmetries symmetries) {
if (symmetries.isEmpty()) return tensor;
int[] tempI = freeIndices.clone();
int[] allFreeIndices = tensor.getIndices().getFree().getAllIndices().copy();
Arrays.sort(tempI);
Arrays.sort(allFreeIndices);
int[] diff = MathUtils.intSetDifference(tempI, allFreeIndices);
System.arraycopy(freeIndices, 0, allFreeIndices, 0, freeIndices.length);
System.arraycopy(diff, 0, allFreeIndices, freeIndices.length, diff.length);
SumBuilder builder = new SumBuilder();
Tensor temp;
for (Symmetry symmetry : symmetries) {
temp =
applyIndexMapping(tensor, allFreeIndices, permute(allFreeIndices, symmetry), new int[0]);
if (symmetry.isAntiSymmetry()) temp = negate(temp);
builder.put(temp);
}
temp = builder.build();
if (temp instanceof Sum) {
// retrieving factor
Complex factor = null, tempF;
for (int i = temp.size() - 1; i >= 0; --i) {
if (temp.get(i) instanceof Product) {
tempF = ((Product) temp.get(i)).getFactor();
assert tempF.isInteger();
tempF = tempF.abs();
} else tempF = Complex.ONE;
if (factor == null) factor = tempF;
assert factor.equals(tempF);
}
if (!factor.isOne())
temp = FastTensors.multiplySumElementsOnFactor((Sum) temp, factor.reciprocal());
return multiply(new Complex(new Rational(1, temp.size())), temp);
}
return temp;
}
@Test
public void run() {
try (Graph g = new Graph();
Session s = new Session(g)) {
TestUtil.transpose_A_times_X(g, new int[][] {{2}, {3}});
try (Tensor x = Tensor.create(new int[][] {{5}, {7}});
AutoCloseableList<Tensor> outputs =
new AutoCloseableList<Tensor>(s.runner().feed("X", x).fetch("Y").run())) {
assertEquals(1, outputs.size());
final int[][] expected = {{31}};
assertEquals(expected, outputs.get(0).copyTo(new int[1][1]));
}
}
}
