1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 package org.apache.commons.math.transform; 18 19 import org.apache.commons.math.FunctionEvaluationException; 20 import org.apache.commons.math.analysis.UnivariateRealFunction; 21 22 /** 23 * Interface for one-dimensional data sets transformations producing real results. 24 * <p>Such transforms include {@link FastSineTransformer sine transform}, 25 * {@link FastCosineTransformer cosine transform} or {@link 26 * FastHadamardTransformer Hadamard transform}. {@link FastFourierTransformer 27 * Fourier transform} is of a different kind and does not implement this 28 * interface since it produces {@link org.apache.commons.math.complex.Complex complex} 29 * results instead of real ones. 30 * </p> 31 * @version $Revision: 1070725 $ $Date: 2011-02-15 02:31:12 +0100 (mar. 15 fvr. 2011) $ 32 * @since 2.0 33 */ 34 public interface RealTransformer { 35 36 /** 37 * Transform the given real data set. 38 * @param f the real data array to be transformed (signal) 39 * @return the real transformed array (spectrum) 40 * @throws IllegalArgumentException if any parameters are invalid 41 */ 42 double[] transform(double f[]) 43 throws IllegalArgumentException; 44 45 /** 46 * Transform the given real function, sampled on the given interval. 47 * @param f the function to be sampled and transformed 48 * @param min the lower bound for the interval 49 * @param max the upper bound for the interval 50 * @param n the number of sample points 51 * @return the real transformed array 52 * @throws FunctionEvaluationException if function cannot be evaluated at some point 53 * @throws IllegalArgumentException if any parameters are invalid 54 */ 55 double[] transform(UnivariateRealFunction f, double min, double max, int n) 56 throws FunctionEvaluationException, IllegalArgumentException; 57 58 /** 59 * Inversely transform the given real data set. 60 * @param f the real data array to be inversely transformed (spectrum) 61 * @return the real inversely transformed array (signal) 62 * @throws IllegalArgumentException if any parameters are invalid 63 */ 64 double[] inversetransform(double f[]) 65 throws IllegalArgumentException; 66 67 /** 68 * Inversely transform the given real function, sampled on the given interval. 69 * @param f the function to be sampled and inversely transformed 70 * @param min the lower bound for the interval 71 * @param max the upper bound for the interval 72 * @param n the number of sample points 73 * @return the real inversely transformed array 74 * @throws FunctionEvaluationException if function cannot be evaluated at some point 75 * @throws IllegalArgumentException if any parameters are invalid 76 */ 77 double[] inversetransform(UnivariateRealFunction f, double min, double max, int n) 78 throws FunctionEvaluationException, IllegalArgumentException; 79 80 } 81
