/*
* Redberry: symbolic tensor computations.
*
* Copyright (c) 2010-2012:
* 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.transformation.integral;
import cc.redberry.core.tensor.Integral;
import cc.redberry.core.tensor.SimpleTensor;
import cc.redberry.core.tensor.Sum;
import cc.redberry.core.tensor.Tensor;
import cc.redberry.transformation.Transformation;
/**
*
* @author Stanislav Poslavsky
*/
public class ExpandIntegral implements Transformation {
public static final ExpandIntegral INSTANCE = new ExpandIntegral();
private ExpandIntegral() {
}
@Override
public Tensor transform(final Tensor tensor) {
if (!(tensor instanceof Integral))
return tensor;
final Integral integral = (Integral) tensor;
final Tensor target = integral.target();
final SimpleTensor[] vars = integral.vars();
if (!(target instanceof Sum))
return tensor;
Sum result = new Sum();
for (Tensor summand : target)
result.add(new Integral(summand.clone(), clone(vars)));
return result;
}
private static SimpleTensor[] clone(final SimpleTensor[] a) {
final SimpleTensor[] r = new SimpleTensor[a.length];
for (int i = 0; i < a.length; ++i)
r[i] = a[i].clone();
return r;
}
}