view src/samer/units/Latch.java @ 8:5e3cbbf173aa tip

Reorganise some more

/*
 *	Copyright (c) 2000, Samer Abdallah, King's College London.
 *	All rights reserved.
 *
 *	This software is provided AS iS and WITHOUT ANY WARRANTY; 
 *	without even the implied warranty of MERCHANTABILITY or 
 *	FITNESS FOR A PARTICULAR PURPOSE.
 */

package samer.units;
import samer.core.*;
import samer.core.types.*;
import samer.tools.*;
import samer.maths.*;
import java.util.*;

/**
	Temporally smoothed thresholding latch
  */

public class Latch extends NamedTask
{
	VDouble	thresh;
	VInteger	countThresh;
	boolean	[] states;
	int		[] counts;
	VVector	output;
	double[]	in,out;
	int		n;
		
	public Latch(VVector input) 
	{
		super("latch");
		n = input.size();
		states = new boolean[n];
		counts = new int[n];
		Shell.push(node);
		thresh = new VDouble("thresh",0.5);
		countThresh = new VInteger("count_thresh",3);
		output = new VVector("output", n);
		Shell.pop();

		in=input.array();
		out=output.array();
	}

	public VVector output() { return output; }

	public void run()
	{
		for (int i=0; i<n; i++) {

			if (!states[i]) {

				// unit is off - check to see if it should be on
				if (in[i]>thresh.value) {
					if (++counts[i] >= countThresh.value) {
						out[i]=in[i];
						states[i]=true;
						counts[i]=0;
					}
				} else counts[i]=0;

			} else {

				// note is on - see about switching it off
				if (in[i]<=0.8*thresh.value) {
					if (++counts[i] >= countThresh.value) {
						out[i]=-1;
						states[i]=false;
						counts[i]=0;
					} else out[i]=in[i];
				} else {
					counts[i]=0;
					out[i]=in[i];
				}
			}
		}
		output.changed();
	}
}