| /* |
| * 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.math4.transform; |
| |
| import java.util.function.DoubleUnaryOperator; |
| import java.util.function.UnaryOperator; |
| |
| /** |
| * Real transforms. |
| */ |
| public interface RealTransform extends UnaryOperator<double[]> { |
| /** |
| * Returns the transform of the specified data set. |
| * |
| * @param f the data array to be transformed (signal). |
| * @return the transformed array (spectrum). |
| * @throws IllegalArgumentException if the transform cannot be performed. |
| */ |
| @Override |
| double[] apply(double[] f); |
| |
| /** |
| * Returns the transform of the specified function. |
| * |
| * @param f Function to be sampled and transformed. |
| * @param min Lower bound (inclusive) of the interval. |
| * @param max Upper bound (exclusive) of the interval. |
| * @param n Number of sample points. |
| * @return the result. |
| * @throws IllegalArgumentException if the transform cannot be performed. |
| */ |
| default double[] apply(DoubleUnaryOperator f, |
| double min, |
| double max, |
| int n) { |
| return apply(TransformUtils.sample(f, min, max, n)); |
| } |
| } |