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view libs/commons-math-2.1/docs/apidocs/src-html/org/apache/commons/math/linear/FieldLUDecomposition.html @ 13:cbf34dd4d7e6
commons-math-2.1 added
| author | dwinter |
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| date | Tue, 04 Jan 2011 10:02:07 +0100 |
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<HTML> <BODY BGCOLOR="white"> <PRE> <FONT color="green">001</FONT> /*<a name="line.1"></a> <FONT color="green">002</FONT> * Licensed to the Apache Software Foundation (ASF) under one or more<a name="line.2"></a> <FONT color="green">003</FONT> * contributor license agreements. See the NOTICE file distributed with<a name="line.3"></a> <FONT color="green">004</FONT> * this work for additional information regarding copyright ownership.<a name="line.4"></a> <FONT color="green">005</FONT> * The ASF licenses this file to You under the Apache License, Version 2.0<a name="line.5"></a> <FONT color="green">006</FONT> * (the "License"); you may not use this file except in compliance with<a name="line.6"></a> <FONT color="green">007</FONT> * the License. You may obtain a copy of the License at<a name="line.7"></a> <FONT color="green">008</FONT> *<a name="line.8"></a> <FONT color="green">009</FONT> * http://www.apache.org/licenses/LICENSE-2.0<a name="line.9"></a> <FONT color="green">010</FONT> *<a name="line.10"></a> <FONT color="green">011</FONT> * Unless required by applicable law or agreed to in writing, software<a name="line.11"></a> <FONT color="green">012</FONT> * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.12"></a> <FONT color="green">013</FONT> * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.13"></a> <FONT color="green">014</FONT> * See the License for the specific language governing permissions and<a name="line.14"></a> <FONT color="green">015</FONT> * limitations under the License.<a name="line.15"></a> <FONT color="green">016</FONT> */<a name="line.16"></a> <FONT color="green">017</FONT> <a name="line.17"></a> <FONT color="green">018</FONT> package org.apache.commons.math.linear;<a name="line.18"></a> <FONT color="green">019</FONT> <a name="line.19"></a> <FONT color="green">020</FONT> import org.apache.commons.math.FieldElement;<a name="line.20"></a> <FONT color="green">021</FONT> <a name="line.21"></a> <FONT color="green">022</FONT> /**<a name="line.22"></a> <FONT color="green">023</FONT> * An interface to classes that implement an algorithm to calculate the<a name="line.23"></a> <FONT color="green">024</FONT> * LU-decomposition of a real matrix.<a name="line.24"></a> <FONT color="green">025</FONT> * <p>The LU-decomposition of matrix A is a set of three matrices: P, L and U<a name="line.25"></a> <FONT color="green">026</FONT> * such that P&times;A = L&times;U. P is a rows permutation matrix that is used<a name="line.26"></a> <FONT color="green">027</FONT> * to rearrange the rows of A before so that it can be decomposed. L is a lower<a name="line.27"></a> <FONT color="green">028</FONT> * triangular matrix with unit diagonal terms and U is an upper triangular matrix.</p><a name="line.28"></a> <FONT color="green">029</FONT> * <p>This interface is based on the class with similar name from the<a name="line.29"></a> <FONT color="green">030</FONT> * <a href="http://math.nist.gov/javanumerics/jama/">JAMA</a> library.</p><a name="line.30"></a> <FONT color="green">031</FONT> * <ul><a name="line.31"></a> <FONT color="green">032</FONT> * <li>a {@link #getP() getP} method has been added,</li><a name="line.32"></a> <FONT color="green">033</FONT> * <li>the <code>det</code> method has been renamed as {@link #getDeterminant()<a name="line.33"></a> <FONT color="green">034</FONT> * getDeterminant},</li><a name="line.34"></a> <FONT color="green">035</FONT> * <li>the <code>getDoublePivot</code> method has been removed (but the int based<a name="line.35"></a> <FONT color="green">036</FONT> * {@link #getPivot() getPivot} method has been kept),</li><a name="line.36"></a> <FONT color="green">037</FONT> * <li>the <code>solve</code> and <code>isNonSingular</code> methods have been replaced<a name="line.37"></a> <FONT color="green">038</FONT> * by a {@link #getSolver() getSolver} method and the equivalent methods provided by<a name="line.38"></a> <FONT color="green">039</FONT> * the returned {@link DecompositionSolver}.</li><a name="line.39"></a> <FONT color="green">040</FONT> * </ul><a name="line.40"></a> <FONT color="green">041</FONT> *<a name="line.41"></a> <FONT color="green">042</FONT> * @param <T> the type of the field elements<a name="line.42"></a> <FONT color="green">043</FONT> * @see <a href="http://mathworld.wolfram.com/LUDecomposition.html">MathWorld</a><a name="line.43"></a> <FONT color="green">044</FONT> * @see <a href="http://en.wikipedia.org/wiki/LU_decomposition">Wikipedia</a><a name="line.44"></a> <FONT color="green">045</FONT> * @version $Revision: 826627 $ $Date: 2009-10-19 06:27:47 -0400 (Mon, 19 Oct 2009) $<a name="line.45"></a> <FONT color="green">046</FONT> * @since 2.0<a name="line.46"></a> <FONT color="green">047</FONT> */<a name="line.47"></a> <FONT color="green">048</FONT> public interface FieldLUDecomposition<T extends FieldElement<T>> {<a name="line.48"></a> <FONT color="green">049</FONT> <a name="line.49"></a> <FONT color="green">050</FONT> /**<a name="line.50"></a> <FONT color="green">051</FONT> * Returns the matrix L of the decomposition.<a name="line.51"></a> <FONT color="green">052</FONT> * <p>L is an lower-triangular matrix</p><a name="line.52"></a> <FONT color="green">053</FONT> * @return the L matrix (or null if decomposed matrix is singular)<a name="line.53"></a> <FONT color="green">054</FONT> */<a name="line.54"></a> <FONT color="green">055</FONT> FieldMatrix<T> getL();<a name="line.55"></a> <FONT color="green">056</FONT> <a name="line.56"></a> <FONT color="green">057</FONT> /**<a name="line.57"></a> <FONT color="green">058</FONT> * Returns the matrix U of the decomposition.<a name="line.58"></a> <FONT color="green">059</FONT> * <p>U is an upper-triangular matrix</p><a name="line.59"></a> <FONT color="green">060</FONT> * @return the U matrix (or null if decomposed matrix is singular)<a name="line.60"></a> <FONT color="green">061</FONT> */<a name="line.61"></a> <FONT color="green">062</FONT> FieldMatrix<T> getU();<a name="line.62"></a> <FONT color="green">063</FONT> <a name="line.63"></a> <FONT color="green">064</FONT> /**<a name="line.64"></a> <FONT color="green">065</FONT> * Returns the P rows permutation matrix.<a name="line.65"></a> <FONT color="green">066</FONT> * <p>P is a sparse matrix with exactly one element set to 1.0 in<a name="line.66"></a> <FONT color="green">067</FONT> * each row and each column, all other elements being set to 0.0.</p><a name="line.67"></a> <FONT color="green">068</FONT> * <p>The positions of the 1 elements are given by the {@link #getPivot()<a name="line.68"></a> <FONT color="green">069</FONT> * pivot permutation vector}.</p><a name="line.69"></a> <FONT color="green">070</FONT> * @return the P rows permutation matrix (or null if decomposed matrix is singular)<a name="line.70"></a> <FONT color="green">071</FONT> * @see #getPivot()<a name="line.71"></a> <FONT color="green">072</FONT> */<a name="line.72"></a> <FONT color="green">073</FONT> FieldMatrix<T> getP();<a name="line.73"></a> <FONT color="green">074</FONT> <a name="line.74"></a> <FONT color="green">075</FONT> /**<a name="line.75"></a> <FONT color="green">076</FONT> * Returns the pivot permutation vector.<a name="line.76"></a> <FONT color="green">077</FONT> * @return the pivot permutation vector<a name="line.77"></a> <FONT color="green">078</FONT> * @see #getP()<a name="line.78"></a> <FONT color="green">079</FONT> */<a name="line.79"></a> <FONT color="green">080</FONT> int[] getPivot();<a name="line.80"></a> <FONT color="green">081</FONT> <a name="line.81"></a> <FONT color="green">082</FONT> /**<a name="line.82"></a> <FONT color="green">083</FONT> * Return the determinant of the matrix<a name="line.83"></a> <FONT color="green">084</FONT> * @return determinant of the matrix<a name="line.84"></a> <FONT color="green">085</FONT> */<a name="line.85"></a> <FONT color="green">086</FONT> T getDeterminant();<a name="line.86"></a> <FONT color="green">087</FONT> <a name="line.87"></a> <FONT color="green">088</FONT> /**<a name="line.88"></a> <FONT color="green">089</FONT> * Get a solver for finding the A &times; X = B solution in exact linear sense.<a name="line.89"></a> <FONT color="green">090</FONT> * @return a solver<a name="line.90"></a> <FONT color="green">091</FONT> */<a name="line.91"></a> <FONT color="green">092</FONT> FieldDecompositionSolver<T> getSolver();<a name="line.92"></a> <FONT color="green">093</FONT> <a name="line.93"></a> <FONT color="green">094</FONT> }<a name="line.94"></a> </PRE> </BODY> </HTML>