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Diffstat (limited to 'src/main/java/org/apache/commons/math3/linear/FieldDecompositionSolver.java')
-rw-r--r-- | src/main/java/org/apache/commons/math3/linear/FieldDecompositionSolver.java | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/src/main/java/org/apache/commons/math3/linear/FieldDecompositionSolver.java b/src/main/java/org/apache/commons/math3/linear/FieldDecompositionSolver.java new file mode 100644 index 0000000..ed5e863 --- /dev/null +++ b/src/main/java/org/apache/commons/math3/linear/FieldDecompositionSolver.java @@ -0,0 +1,79 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.commons.math3.linear; + +import org.apache.commons.math3.FieldElement; + +/** + * Interface handling decomposition algorithms that can solve A × X = B. + * + * <p>Decomposition algorithms decompose an A matrix has a product of several specific matrices from + * which they can solve A × X = B in least squares sense: they find X such that ||A × X + * - B|| is minimal. + * + * <p>Some solvers like {@link FieldLUDecomposition} can only find the solution for square matrices + * and when the solution is an exact linear solution, i.e. when ||A × X - B|| is exactly 0. + * Other solvers can also find solutions with non-square matrix A and with non-null minimal norm. If + * an exact linear solution exists it is also the minimal norm solution. + * + * @param <T> the type of the field elements + * @since 2.0 + */ +public interface FieldDecompositionSolver<T extends FieldElement<T>> { + + /** + * Solve the linear equation A × X = B for matrices A. + * + * <p>The A matrix is implicit, it is provided by the underlying decomposition algorithm. + * + * @param b right-hand side of the equation A × X = B + * @return a vector X that minimizes the two norm of A × X - B + * @throws org.apache.commons.math3.exception.DimensionMismatchException if the matrices + * dimensions do not match. + * @throws SingularMatrixException if the decomposed matrix is singular. + */ + FieldVector<T> solve(final FieldVector<T> b); + + /** + * Solve the linear equation A × X = B for matrices A. + * + * <p>The A matrix is implicit, it is provided by the underlying decomposition algorithm. + * + * @param b right-hand side of the equation A × X = B + * @return a matrix X that minimizes the two norm of A × X - B + * @throws org.apache.commons.math3.exception.DimensionMismatchException if the matrices + * dimensions do not match. + * @throws SingularMatrixException if the decomposed matrix is singular. + */ + FieldMatrix<T> solve(final FieldMatrix<T> b); + + /** + * Check if the decomposed matrix is non-singular. + * + * @return true if the decomposed matrix is non-singular + */ + boolean isNonSingular(); + + /** + * Get the inverse (or pseudo-inverse) of the decomposed matrix. + * + * @return inverse matrix + * @throws SingularMatrixException if the decomposed matrix is singular. + */ + FieldMatrix<T> getInverse(); +} |