141 lines
4.1 KiB
Java
141 lines
4.1 KiB
Java
//******************************************************************************
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//
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// File: SampledXYSeries.java
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// Package: edu.rit.numeric
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// Unit: Class edu.rit.numeric.SampledXYSeries
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//
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// This Java source file is copyright (C) 2013 by Alan Kaminsky. All rights
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// reserved. For further information, contact the author, Alan Kaminsky, at
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// ark@cs.rit.edu.
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//
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// This Java source file is part of the Parallel Java 2 Library ("PJ2"). PJ2 is
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// free software; you can redistribute it and/or modify it under the terms of
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// the GNU General Public License as published by the Free Software Foundation;
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// either version 3 of the License, or (at your option) any later version.
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//
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// PJ2 is distributed in the hope that it will be useful, but WITHOUT ANY
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// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
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// A PARTICULAR PURPOSE. See the GNU General Public License for more details.
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//
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// A copy of the GNU General Public License is provided in the file gpl.txt. You
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// may also obtain a copy of the GNU General Public License on the World Wide
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// Web at http://www.gnu.org/licenses/gpl.html.
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//
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//******************************************************************************
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package edu.rit.numeric;
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/**
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* Class SampledXYSeries provides a series of (<I>x,y</I>) pairs of real values
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* (type <TT>double</TT>) where the Y values are computed by sampling a
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* {@linkplain Function} for a series of X values.
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* <P>
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* Class SampledXYSeries is implemented to minimize space rather than time. Each
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* time <TT>x()</TT> is called, the <I>x</I> value is computed anew. Each time
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* <TT>y()</TT> is called, the <I>x</I> value is computed anew, then the
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* <I>y</I> value is computed anew by evaluating the function at <I>x</I>.
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*
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* @author Alan Kaminsky
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* @version 06-Jul-2007
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*/
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public class SampledXYSeries
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extends XYSeries
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{
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// Hidden data members.
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private Function myFunction;
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private double myXinit;
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private double myDelta;
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private int myLength;
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// Exported constructors.
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/**
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* Construct a new sampled series sampling values of the given function. The
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* <I>y</I> values at indexes 0, 1, 2, ... <TT>len-1</TT> are computed by
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* evaluating <TT>theFunction</TT> at the <I>x</I> values <TT>xinit</TT>,
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* <TT>xinit+delta</TT>, <TT>xinit+2*delta</TT>, ...
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* <TT>xinit+(len-1)*delta</TT>.
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*
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* @param theFunction Function to sample.
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* @param xinit Initial <I>x</I> value.
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* @param delta Difference between successive <I>x</I> values.
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* @param len Length (number of (<I>x,y</I>) pairs).
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*
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* @exception NullPointerException
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* (unchecked exception) Thrown if <TT>theFunction</TT> is null.
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* @exception IllegalArgumentException
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* (unchecked exception) Thrown if <TT>len</TT> is less than 0.
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*/
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public SampledXYSeries
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(Function theFunction,
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double xinit,
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double delta,
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int len)
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{
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super();
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if (theFunction == null)
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{
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throw new NullPointerException
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("SampledXYSeries(): theFunction is null");
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}
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if (len < 0)
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{
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throw new IllegalArgumentException
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("SampledXYSeries(): len = " + len + " illegal");
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}
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myFunction = theFunction;
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myXinit = xinit;
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myDelta = delta;
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myLength = len;
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}
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// Exported operations.
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/**
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* Returns the number of values in this series.
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*
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* @return Length.
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*/
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public int length()
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{
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return myLength;
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}
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/**
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* Returns the given X value in this series.
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*
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* @param i Index.
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*
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* @return The X value in this series at index <TT>i</TT>.
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*
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* @exception ArrayIndexOutOfBoundsException
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* (unchecked exception) Thrown if <TT>i</TT> is not in the range
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* <TT>0</TT> .. <TT>length()-1</TT>.
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*/
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public double x
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(int i)
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{
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return myXinit + i * myDelta;
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}
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/**
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* Returns the given Y value in this series.
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*
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* @param i Index.
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*
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* @return The Y value in this series at index <TT>i</TT>.
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*
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* @exception ArrayIndexOutOfBoundsException
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* (unchecked exception) Thrown if <TT>i</TT> is not in the range
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* <TT>0</TT> .. <TT>length()-1</TT>.
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*/
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public double y
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(int i)
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{
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return myFunction.f (x (i));
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}
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}
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