/*
* 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.substitutions.n;
import cc.redberry.core.context.CC;
import cc.redberry.core.tensor.*;
import cc.redberry.core.tensor.functions.*;
import cc.redberry.transformation.Transformation;
import cc.redberry.transformation.substitutions.ZeroSimpleTensorSubstitution;
import java.util.HashMap;
import java.util.Map;
/**
*
* @author Dmitry Bolotin
* @author Stanislav Poslavsky
*/
public final class Substitutions {
public static Transformation createSubstitution(String strin) {
return createSubstitution(strin, CC.withMetric());
}
public static Transformation createSubstitution(String strin, boolean allowDiffStates) {
String[] split = strin.split("=");
if (split.length != 2)
throw new IllegalArgumentException();
return createSubstitution(CC.parse(split[0]), CC.parse(split[1]), allowDiffStates);
}
public static Transformation createSubstitution(Tensor from, Tensor to) {
if (TensorNumber.isZero(to)) {
if (!(from instanceof SimpleTensor))
throw new UnsupportedOperationException();
return new ZeroSimpleTensorSubstitution((SimpleTensor) from, CC.withMetric());
}
return createSubstitution(from, to, CC.withMetric());
}
public static Transformation createSubstitution(Tensor from, Tensor to, boolean allowDiffStates) {
SubstitutionProvider provider = map.get(from.getClass());
if (provider == null)
throw new RuntimeException("Unsuported tensor type");
return provider.createSubstitution(from, to, allowDiffStates);
}
private static final Map<Class, SubstitutionProvider> map = new HashMap<>();
static {
map.put(SimpleTensor.class, SimpleSubstitution.SIMPLE_SUBSTITUTION_PROVIDER);
map.put(TensorField.class, TensorFieldSubstitution.TENSOR_FIELD_PROVIDER);
map.put(Sin.class, SimpleSubstitution.SIMPLE_SUBSTITUTION_PROVIDER);
map.put(Cos.class, SimpleSubstitution.SIMPLE_SUBSTITUTION_PROVIDER);
map.put(Tan.class, SimpleSubstitution.SIMPLE_SUBSTITUTION_PROVIDER);
map.put(CoTan.class, SimpleSubstitution.SIMPLE_SUBSTITUTION_PROVIDER);
map.put(Exp.class, SimpleSubstitution.SIMPLE_SUBSTITUTION_PROVIDER);
map.put(Pow.class, SimpleSubstitution.SIMPLE_SUBSTITUTION_PROVIDER);
map.put(Log.class, SimpleSubstitution.SIMPLE_SUBSTITUTION_PROVIDER);
map.put(TensorNumber.class, SimpleSubstitution.SIMPLE_SUBSTITUTION_PROVIDER);
map.put(Fraction.class, SimpleSubstitution.SIMPLE_SUBSTITUTION_PROVIDER);
map.put(Product.class, ProductSubstitution.PROVIDER_SUBSTITUTION_PRODUCT);
}
}