JSci.maths.matrices.DoubleSparseSquareMatrix Maven / Gradle / Ivy
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JSci is a set of open source Java packages. The aim is to encapsulate scientific methods/principles in the most natural way possible. As such they should greatly aid the development of scientific based software.
It offers: abstract math interfaces, linear algebra (support for various matrix and vector types), statistics (including probability distributions), wavelets, newtonian mechanics, chart/graph components (AWT and Swing), MathML DOM implementation, ...
Note: some packages, like javax.comm, for the astro and instruments package aren't listed as dependencies (not available).
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package JSci.maths.matrices; import JSci.GlobalSettings; import JSci.maths.Mapping; import JSci.maths.DimensionException; import JSci.maths.vectors.AbstractDoubleVector; import JSci.maths.vectors.DoubleVector; import JSci.maths.vectors.DoubleSparseVector; /** * The DoubleSparseSquareMatrix class provides an object for encapsulating sparse square matrices. * Uses compressed row storage (Yale sparse matrix format). * @version 1.4 * @author Mark Hale */ public final class DoubleSparseSquareMatrix extends AbstractDoubleSquareMatrix { /** * Matrix elements. */ private double elements[]; /** * Sparse indexing data. * Contains the column positions of each element, * e.g.
* to hold the pivot information (null if not interested) * @return an array with [0] containing the L-matrix * and [1] containing the U-matrix. */ public AbstractDoubleSquareMatrix[] luDecompose(int pivot[]) { AbstractDoubleSquareMatrix[] LU = luDecompose_cache(pivot); if(LU != null) return LU; final double arrayL[][]=new double[numRows][numCols]; final double arrayU[][]=new double[numRows][numCols]; if(pivot==null) pivot=new int[numRows+1]; for(int i=0;icolPos[n]
is the column position * of then
th element. */ private int colPos[]; /** * Sparse indexing data. * Contains the indices of the start of each row, * e.g.rows[i]
is the index * where thei
th row starts. */ private int rows[]; /** * Amount by which to increase the capacity. */ private int capacityIncrement = 1; /** * Constructs an empty matrix. * @param size the number of rows/columns */ public DoubleSparseSquareMatrix(final int size) { super(size); elements=new double[0]; colPos=new int[0]; rows=new int[numRows+1]; } public DoubleSparseSquareMatrix(final int size, int capacityIncrement) { this(size); this.capacityIncrement = capacityIncrement; } /** * Constructs a matrix from an array. * @param array an assigned value * @exception MatrixDimensionException If the array is not square. */ public DoubleSparseSquareMatrix(final double array[][]) { super(array.length); rows=new int[numRows+1]; int n=0; for(int i=0;iGlobalSettings.ZERO_TOL) n++; } } elements=new double[n]; colPos=new int[n]; n=0; for(int i=0;i GlobalSettings.ZERO_TOL) { elements[n]=array[i][j]; colPos[n]=j; n++; } } } rows[numRows]=n; } /** * Compares two double sparse square matrices for equality. * @param m a double matrix */ public boolean equals(AbstractDoubleSquareMatrix m, double tol) { if(numRows==m.numRows && numCols==m.numCols) { if(m instanceof DoubleSparseSquareMatrix) { return this.equals((DoubleSparseSquareMatrix)m); } else { double sumSqr = 0; for(int i=0;i =0 && i =0 && j =0 && i =0 && j GlobalSettings.ZERO_TOL) { // expand if(rows[numRows] == elements.length) { // increase capacity final double oldMatrix[]=elements; final int oldColPos[]=colPos; elements=new double[oldMatrix.length+capacityIncrement]; colPos=new int[oldColPos.length+capacityIncrement]; System.arraycopy(oldMatrix,0,elements,0,p); System.arraycopy(oldColPos,0,colPos,0,p); System.arraycopy(oldMatrix,p,elements,p+1,oldMatrix.length-p); System.arraycopy(oldColPos,p,colPos,p+1,oldColPos.length-p); } else { System.arraycopy(elements,p,elements,p+1,rows[numRows]-p); System.arraycopy(colPos,p,colPos,p+1,rows[numRows]-p); } elements[p]=x; colPos[p]=j; for(int k=i+1;k -norm. */ public double infNorm() { double result=0.0,tmpResult; for(int j,i=0;i result) result=tmpResult; } return result; } /** * Returns the Frobenius (l2) norm. */ public double frobeniusNorm() { double result=0.0; for(int i=0;i rows()+1 max) { max=tmp; pivotrow=i; } } // swap row j with pivotrow if(pivotrow!=j) { double[] tmprow = arrayU[j]; arrayU[j] = arrayU[pivotrow]; arrayU[pivotrow] = tmprow; int k=pivot[j]; pivot[j]=pivot[pivotrow]; pivot[pivotrow]=k; // update parity pivot[numRows]=-pivot[numRows]; } // divide by pivot for(int i=j+1;i