samer@0: /*
samer@0:  *	Copyright (c) 2000, Samer Abdallah, King's College London.
samer@0:  *	All rights reserved.
samer@0:  *
samer@0:  *	This software is provided AS iS and WITHOUT ANY WARRANTY; 
samer@0:  *	without even the implied warranty of MERCHANTABILITY or 
samer@0:  *	FITNESS FOR A PARTICULAR PURPOSE.
samer@0:  */
samer@0: 
samer@0: package samer.maths;
samer@0: import  samer.tools.*;
samer@0: 
samer@0: public class MatrixTimesVector extends VectorFunctionOfVector implements SafeTask
samer@0: {
samer@0: 	int m, n;
samer@0: 	double [][] a;
samer@0: 	double [] x, y, arow;
samer@0: 
samer@0: 	public MatrixTimesVector( Vec out, Matrix matrix, Vec in) {
samer@0: 		this(out.array(),matrix,in.array());
samer@0: 	}
samer@0: 
samer@0: 	public MatrixTimesVector(Matrix matrix)
samer@0: 	{
samer@0: 		n = matrix.getRowDimension();
samer@0: 		m = matrix.getColumnDimension();
samer@0: 		a = matrix.getArray();
samer@0: 	}
samer@0: 	
samer@0: 	public MatrixTimesVector( double [] out, Matrix matrix)
samer@0: 	{
samer@0: 		n = matrix.getRowDimension();
samer@0: 		m = matrix.getColumnDimension();
samer@0: 		a = matrix.getArray();
samer@0: 		y = out;
samer@0: 	}
samer@0: 
samer@0: 	public MatrixTimesVector( double [] out, Matrix matrix, double [] in)
samer@0: 	{
samer@0: 		n = matrix.getRowDimension();
samer@0: 		m = matrix.getColumnDimension();
samer@0: 		a = matrix.getArray();
samer@0: 		x = in;
samer@0: 		y = out;
samer@0: 	}
samer@0: 
samer@0: 	public void dispose() {}
samer@0: 	public void starting() {}
samer@0: 	public void stopping() {}
samer@0: 	public void run() {
samer@0: 		for (int i=0; i<n; i++) {
samer@0: 			double t=0;
samer@0: 			arow=a[i];
samer@0: 			for (int j=0; j<m; j++) t+=arow[j]*x[j];
samer@0: 			y[i]=t;
samer@0: 		}
samer@0: 	}
samer@0: 
samer@0: 	public void apply(double [] x, double [] y) {
samer@0: 		for (int i=0; i<n; i++) {
samer@0: 			double t=0;
samer@0: 			arow=a[i];
samer@0: 			for (int j=0; j<m; j++) t+=arow[j]*x[j];
samer@0: 			y[i]=t;
samer@0: 		}
samer@0: 	}
samer@0: }