/*
* Redberry: symbolic tensor computations.
*
* Copyright (c) 2010-2013:
* Stanislav Poslavsky <stvlpos@mail.ru>
* Bolotin Dmitriy <bolotin.dmitriy@gmail.com>
*
* This file is part of Redberry.
*
* Redberry is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Redberry is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Redberry. If not, see <http://www.gnu.org/licenses/>.
*/
package cc.redberry.core.transformations.substitutions;
import cc.redberry.core.indexmapping.IndexMappingBuffer;
import cc.redberry.core.indexmapping.IndexMappings;
import cc.redberry.core.indices.Indices;
import cc.redberry.core.tensor.ApplyIndexMapping;
import cc.redberry.core.tensor.Tensor;
import cc.redberry.core.tensor.TensorField;
import cc.redberry.core.tensor.Tensors;
import cc.redberry.core.utils.TensorUtils;
import java.util.ArrayList;
import java.util.List;
/**
* @author Dmitry Bolotin
* @author Stanislav Poslavsky
*/
class PrimitiveTensorFieldSubstitution extends PrimitiveSubstitution {
public PrimitiveTensorFieldSubstitution(Tensor from, Tensor to) {
super(from, to);
}
@Override
Tensor newTo_(Tensor currentNode, SubstitutionIterator iterator) {
TensorField currentField = (TensorField) currentNode;
TensorField from = (TensorField) this.from;
IndexMappingBuffer buffer = IndexMappings.simpleTensorsPort(from, currentField).take();
if (buffer == null)
return currentNode;
Indices[] fromIndices = from.getArgIndices(), currentIndices = currentField.getArgIndices();
List<Tensor> argFrom = new ArrayList<>(), argTo = new ArrayList<>();
Tensor fArg;
int[] cIndices, fIndices;
int i;
for (i = from.size() - 1; i >= 0; --i) {
if (IndexMappings.mappingExists(currentNode.get(i), from.get(i)))
continue;
fIndices = fromIndices[i].getAllIndices().copy();
cIndices = currentIndices[i].getAllIndices().copy();
assert cIndices.length == fIndices.length;
fArg = ApplyIndexMapping.applyIndexMapping(from.get(i), fIndices, cIndices, new int[0]);
argFrom.add(fArg);
argTo.add(currentNode.get(i));
}
Tensor newTo = to;
newTo = new SubstitutionTransformation(
argFrom.toArray(new Tensor[argFrom.size()]),
argTo.toArray(new Tensor[argTo.size()]),
false).transform(newTo);
if (!TensorUtils.isSymbolic(newTo))
newTo = ApplyIndexMapping.applyIndexMapping(newTo, buffer, iterator.getForbidden());
else if (buffer.getSign())
newTo = Tensors.negate(newTo);
return newTo;
}
}