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.units;
samer@0: import  samer.core.*;
samer@0: import  samer.maths.*;
samer@0: import  samer.tools.*;
samer@0: 
samer@0: /*
samer@0:  *		Takes successive input vectors and stacks them into
samer@0:  *		one big output vector. Requires a task which it will
samer@0:  *		run to obtain each input vector.
samer@0:  */
samer@0: 
samer@0: public class Stacker implements Task
samer@0: {
samer@0: 	Node	node;
samer@0: 	Task	nextvec;
samer@0: 	Vec	srcvec;
samer@0: 	int	size, step;
samer@0: 	VVector	target;
samer@0: 	double []	a, b;
samer@0: 	int	k0, k1, k2;
samer@0: 
samer@0: 	public Stacker(Vec v, Task t, int size, int step) { this(v,t,size,step,v.size()); }
samer@0: 	public Stacker(Vec v, Task t, int size, int step, int height)
samer@0: 	{
samer@0: 		node = new Node("stacker");
samer@0: 
samer@0: 		Shell.push(node);
samer@0: 		srcvec=v; nextvec=t;
samer@0: 		this.size = size;
samer@0: 		this.step = step;
samer@0: 
samer@0: 		k0=height;
samer@0: 		k1=step*k0;
samer@0: 		k2=(size-step)*k0;
samer@0: 
samer@0: 		target = new VVector("output",k0*size);
samer@0: 		a = target.array();
samer@0: 		b = srcvec.array();
samer@0: 		Mathx.zero(a);
samer@0: 
samer@0: 		Shell.pop();
samer@0: 	}
samer@0: 
samer@0: 	public void dispose() {
samer@0: 		nextvec.dispose();
samer@0: 		target.dispose();
samer@0: 		a=b=null;
samer@0: 	}
samer@0: 
samer@0: 	public VVector output() { return target; }
samer@0: 
samer@0: 	public void starting() { nextvec.starting(); }
samer@0: 	public void stopping() { nextvec.stopping(); }
samer@0: 	public void run() throws Exception
samer@0: 	{
samer@0: 		// make some room in packed matrix
samer@0: 		System.arraycopy(a,k1,a,0,k2);
samer@0: 
samer@0: 		for (int i=0, j=k2; i<step; i++) {
samer@0: 			nextvec.run();
samer@0: 			// copy vec into packed matrix
samer@0: 			System.arraycopy(b,0,a,j,k0);
samer@0: 			j+=k0;
samer@0: 		}
samer@0: 		target.changed();
samer@0: 	}
samer@0: }