| /* |
| * 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.stat.descriptive; |
| |
| import java.io.Serializable; |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| import org.apache.commons.math3.exception.MathIllegalArgumentException; |
| import org.apache.commons.math3.stat.descriptive.UnivariateStatistic; |
| import org.apache.commons.math3.stat.descriptive.DescriptiveStatistics; |
| import org.apache.commons.math3.util.DefaultTransformer; |
| import org.apache.commons.math3.util.FastMath; |
| import org.apache.commons.math3.util.NumberTransformer; |
| |
| /** |
| */ |
| public class ListUnivariateImpl extends DescriptiveStatistics implements Serializable { |
| |
| /** Serializable version identifier */ |
| private static final long serialVersionUID = -8837442489133392138L; |
| |
| /** |
| * Holds a reference to a list - GENERICs are going to make |
| * our lives easier here as we could only accept List<Number> |
| */ |
| protected List<Object> list; |
| |
| /** Number Transformer maps Objects to Number for us. */ |
| protected NumberTransformer transformer; |
| |
| /** |
| * No argument Constructor |
| */ |
| public ListUnivariateImpl(){ |
| this(new ArrayList<Object>()); |
| } |
| |
| /** |
| * Construct a ListUnivariate with a specific List. |
| * @param list The list that will back this DescriptiveStatistics |
| */ |
| public ListUnivariateImpl(List<Object> list) { |
| this(list, new DefaultTransformer()); |
| } |
| |
| /** |
| * Construct a ListUnivariate with a specific List. |
| * @param list The list that will back this DescriptiveStatistics |
| * @param transformer the number transformer used to convert the list items. |
| */ |
| public ListUnivariateImpl(List<Object> list, NumberTransformer transformer) { |
| super(); |
| this.list = list; |
| this.transformer = transformer; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public double[] getValues() { |
| |
| int length = list.size(); |
| |
| // If the window size is not INFINITE_WINDOW AND |
| // the current list is larger that the window size, we need to |
| // take into account only the last n elements of the list |
| // as definied by windowSize |
| |
| final int wSize = getWindowSize(); |
| if (wSize != DescriptiveStatistics.INFINITE_WINDOW && wSize < list.size()) { |
| length = list.size() - FastMath.max(0, list.size() - wSize); |
| } |
| |
| // Create an array to hold all values |
| double[] copiedArray = new double[length]; |
| |
| for (int i = 0; i < copiedArray.length; i++) { |
| copiedArray[i] = getElement(i); |
| } |
| return copiedArray; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public double getElement(int index) { |
| |
| double value = Double.NaN; |
| |
| int calcIndex = index; |
| |
| final int wSize = getWindowSize(); |
| if (wSize != DescriptiveStatistics.INFINITE_WINDOW && wSize < list.size()) { |
| calcIndex = (list.size() - wSize) + index; |
| } |
| |
| |
| try { |
| value = transformer.transform(list.get(calcIndex)); |
| } catch (MathIllegalArgumentException e) { |
| e.printStackTrace(); |
| } |
| |
| return value; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public long getN() { |
| int n = 0; |
| |
| final int wSize = getWindowSize(); |
| if (wSize != DescriptiveStatistics.INFINITE_WINDOW) { |
| if (list.size() > wSize) { |
| n = wSize; |
| } else { |
| n = list.size(); |
| } |
| } else { |
| n = list.size(); |
| } |
| return n; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public void addValue(double v) { |
| list.add(Double.valueOf(v)); |
| } |
| |
| /** |
| * Adds an object to this list. |
| * @param o Object to add to the list |
| */ |
| public void addObject(Object o) { |
| list.add(o); |
| } |
| |
| /** |
| * Clears all statistics. |
| * <p> |
| * <strong>N.B.: </strong> This method has the side effect of clearing the underlying list. |
| */ |
| @Override |
| public void clear() { |
| list.clear(); |
| } |
| |
| /** |
| * Apply the given statistic to this univariate collection. |
| * @param stat the statistic to apply |
| * @return the computed value of the statistic. |
| */ |
| @Override |
| public double apply(UnivariateStatistic stat) { |
| double[] v = this.getValues(); |
| |
| if (v != null) { |
| return stat.evaluate(v, 0, v.length); |
| } |
| return Double.NaN; |
| } |
| |
| /** |
| * Access the number transformer. |
| * @return the number transformer. |
| */ |
| public NumberTransformer getTransformer() { |
| return transformer; |
| } |
| |
| /** |
| * Modify the number transformer. |
| * @param transformer the new number transformer. |
| */ |
| public void setTransformer(NumberTransformer transformer) { |
| this.transformer = transformer; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public void setWindowSize(int windowSize) { |
| super.setWindowSize(windowSize); |
| //Discard elements from the front of the list if the windowSize is less than |
| // the size of the list. |
| int extra = list.size() - windowSize; |
| for (int i = 0; i < extra; i++) { |
| list.remove(0); |
| } |
| } |
| |
| } |