| /* |
| * 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.solr.client.solrj.io.eval; |
| |
| import java.io.IOException; |
| import java.util.List; |
| import java.util.ArrayList; |
| |
| import org.apache.commons.math3.analysis.UnivariateFunction; |
| import org.apache.commons.math3.analysis.polynomials.PolynomialFunction; |
| import org.apache.commons.math3.fitting.PolynomialCurveFitter; |
| |
| import org.apache.commons.math3.fitting.WeightedObservedPoints; |
| import org.apache.solr.client.solrj.io.stream.expr.StreamExpression; |
| import org.apache.solr.client.solrj.io.stream.expr.StreamFactory; |
| |
| public class PolyFitDerivativeEvaluator extends RecursiveNumericEvaluator implements ManyValueWorker { |
| protected static final long serialVersionUID = 1L; |
| |
| public PolyFitDerivativeEvaluator(StreamExpression expression, StreamFactory factory) throws IOException{ |
| super(expression, factory); |
| } |
| |
| @Override |
| @SuppressWarnings({"unchecked"}) |
| public Object doWork(Object... objects) throws IOException{ |
| |
| if(objects.length > 3) { |
| throw new IOException("polyfitDerivative function takes a maximum of 3 arguments."); |
| } |
| |
| Object first = objects[0]; |
| |
| double[] x = null; |
| double[] y = null; |
| int degree = 3; |
| |
| if(objects.length == 1) { |
| //Only the y values passed |
| |
| y = ((List) first).stream().mapToDouble(value -> ((Number) value).doubleValue()).toArray(); |
| x = new double[y.length]; |
| for(int i=0; i<y.length; i++) { |
| x[i] = i; |
| } |
| |
| } else if(objects.length == 3) { |
| // x, y and degree passed |
| |
| Object second = objects[1]; |
| x = ((List) first).stream().mapToDouble(value -> ((Number) value).doubleValue()).toArray(); |
| y = ((List) second).stream().mapToDouble(value -> ((Number) value).doubleValue()).toArray(); |
| degree = ((Number)objects[2]).intValue(); |
| } else if(objects.length == 2) { |
| if(objects[1] instanceof List) { |
| // x and y passed |
| Object second = objects[1]; |
| x = ((List) first).stream().mapToDouble(value -> ((Number) value).doubleValue()).toArray(); |
| y = ((List) second).stream().mapToDouble(value -> ((Number) value).doubleValue()).toArray(); |
| } else { |
| // y and degree passed |
| y = ((List) first).stream().mapToDouble(value -> ((Number) value).doubleValue()).toArray(); |
| x = new double[y.length]; |
| for(int i=0; i<y.length; i++) { |
| x[i] = i; |
| } |
| |
| degree = ((Number)objects[1]).intValue(); |
| } |
| } |
| |
| PolynomialCurveFitter curveFitter = PolynomialCurveFitter.create(degree); |
| WeightedObservedPoints points = new WeightedObservedPoints(); |
| for(int i=0; i<x.length; i++) { |
| points.add(x[i], y[i]); |
| } |
| |
| double[] coef = curveFitter.fit(points.toList()); |
| PolynomialFunction pf = new PolynomialFunction(coef); |
| UnivariateFunction univariateFunction = pf.derivative(); |
| |
| @SuppressWarnings({"rawtypes"}) |
| List list = new ArrayList(); |
| for(double xvalue : x) { |
| double yvalue= univariateFunction.value(xvalue); |
| list.add(yvalue); |
| } |
| |
| return list; |
| } |
| } |