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.core.*;
samer@0: import	samer.tools.*;
samer@0: import	java.util.*;
samer@0: 
samer@0: 
samer@0: /**
samer@0: 	An agent which allows the creation of vectors and
samer@0: 	matrices, and can also arrange for them to be
samer@0: 	multiplied as part of the current task list
samer@0:  */
samer@0: 
samer@0: public class Ops
samer@0: {
samer@0: 	public static Task update(final Viewable v) {
samer@0: 		return new AnonymousTask() { public void run() { v.changed(); } };
samer@0: 	}
samer@0: 
samer@0: 	public static Task times(VVector out, Matrix A, VVector x) {
samer@0: 		return new MatrixTimesVector(out,A,x);
samer@0: 	}
samer@0: 
samer@0: 	// copy as much as possible from one vector to another
samer@0: 	public static Task transfer(final Vec in, final Vec out) {
samer@0: 		final int len=Math.min(in.size(),out.size());
samer@0: 		double src[]=in.array();
samer@0: 
samer@0: 		if (src!=null) 	return new ArrayCopy(src,0,out.array(),0,len);
samer@0: 		else 				return new IteratorCopy(in,out,len);
samer@0: 	}
samer@0: 
samer@0: 	// copy a given range from one vector to another
samer@0: 	public static Task transfer(
samer@0: 		final Vec in, int inpos, final Vec out, int outpos, int len)
samer@0: 	{
samer@0: 		return new ArrayCopy(in.array(),inpos,out.array(),outpos,len);
samer@0: 	}
samer@0: 
samer@0: 	// copy a listed elements to another vector
samer@0: 	public static Task transfer(final Vec in, final Vec out, final int[] elements) {
samer@0: 		return new AnonymousTask() {
samer@0: 			double [] dst=out.array();
samer@0: 			double [] src=in.array();
samer@0: 			int N=elements.length;
samer@0: 			public void run() {
samer@0: 				for (int i=0; i<N; i++) dst[i]=src[elements[i]];
samer@0: 			}
samer@0: 		};
samer@0: 	}
samer@0: 
samer@0: 	public static Task apply(Vec vout, final Function f, Vec vin) {
samer@0: 		final double [] in = vin.array();
samer@0: 		final double [] out = vout.array();
samer@0: 		return new AnonymousTask() {
samer@0: 			Function fn=f;
samer@0: 			public void run() { fn.apply(in,out); }
samer@0: 			public void setFunction(Function fn) { this.fn=fn; }
samer@0: 		};
samer@0: 	}
samer@0: 
samer@0: 	public static Task apply(final Function fn, Vec vin) {
samer@0: 		final double [] in = vin.array();
samer@0: 		return new AnonymousTask() {
samer@0: 			public void run() { fn.apply(in); }
samer@0: 		};
samer@0: 	}
samer@0: 
samer@0: 	public static Task apply(final VVector vout, final VectorFunctionOfVector fn, VVector vin) {
samer@0: 		final double [] in = vin.array();
samer@0: 		final double [] out= vout.array();
samer@0: 		return new AnonymousTask() {
samer@0: 			public void run() { fn.apply(in,out); vout.changed(); }
samer@0: 		};
samer@0: 	}
samer@0: 
samer@0: 	public static void apply( Function fn, Matrix A) {
samer@0: 		double _A[][]=A.getArray();
samer@0: 		int N=A.getRowDimension();
samer@0: 		for (int i=0; i<N; i++) fn.apply(_A[i]); 
samer@0: 		A.changed();
samer@0: 	}
samer@0: 
samer@0: 	public static void apply( Function fn, Matrix B, Matrix A) {
samer@0: 		double _A[][]=A.getArray(),_B[][]=B.getArray();
samer@0: 		int N=A.getRowDimension();
samer@0: 		for (int i=0; i<N; i++) fn.apply(_B[i],_A[i]); 
samer@0: 		A.changed();
samer@0: 	}
samer@0: 
samer@0: 
samer@0: 	
samer@0: 	public static Task plusEquals(final VVector x, final VVector y) {
samer@0: 		final double [] _x=x.array(), _y=y.array();
samer@0: 		return new AnonymousTask() {
samer@0: 			public void run() { Mathx.add(_x,_y); x.changed(); }
samer@0: 		};
samer@0: 	}
samer@0: 	
samer@0: 	public static Task timesEquals(final VVector x, final VVector y) {
samer@0: 		final double [] _x=x.array(), _y=y.array();
samer@0: 		return new AnonymousTask() {
samer@0: 			public void run() { Mathx.mul(_x,_y); x.changed(); }
samer@0: 		};
samer@0: 	}
samer@0: 
samer@0: 	public static Task apply(final VectorFunctionOfVector fn, final VVector vinout) {
samer@0: 		final double [] in = vinout.array();
samer@0: 		return new AnonymousTask() {
samer@0: 			public void run() { fn.apply(in); vinout.changed(); }
samer@0: 		};
samer@0: 	}
samer@0: 
samer@0: 	/**
samer@0: 		causes a task to run whenever an observable changes
samer@0: 	 */
samer@0: 	public static void triggerTask( final Task task, Observable obs)
samer@0: 	{
samer@0: 		obs.addObserver( new Observer() {
samer@0: 			public void update(Observable o, Object a) { 
samer@0: 				if (a==Viewable.DISPOSING) {
samer@0: 					o.deleteObserver(this);
samer@0: 					task.dispose();
samer@0: 					return;
samer@0: 				}
samer@0: 				try { task.run(); }
samer@0: 				catch (Exception ex) {}
samer@0: 			}
samer@0: 		} );
samer@0: 	}
samer@0: 
samer@0: 	public static class ArrayCopy extends NullTask {
samer@0: 		Object src, dst;
samer@0: 		int		i, j, n;
samer@0: 		public ArrayCopy(Object s, int spos, Object d, int dpos, int len) {
samer@0: 			src=s; dst=d; i=spos; j=dpos; n=len;
samer@0: 		}
samer@0: 		public void run() { System.arraycopy(src,i,dst,j,n);	}
samer@0: 	}
samer@0: 
samer@0: 	public static class IteratorCopy extends NullTask {
samer@0: 		Vec	src, dst;
samer@0: 		int 	N;
samer@0: 		
samer@0: 		public IteratorCopy(Vec src, Vec dst, int N) {
samer@0: 			this.src=src; this.dst=dst; this.N=N;
samer@0: 		}
samer@0: 		
samer@0: 		public void run() {
samer@0: 			Vec.Iterator it=src.iterator();
samer@0: 			double	[] a=dst.array();
samer@0: 			for (int i=0; i<N; i++) a[i]=it.next();
samer@0: 		}
samer@0: 	}
samer@0: }