/* -*- tab-width: 4 -*-
*
* Electric(tm) VLSI Design System
*
* File: ChromosomeMutationPadding.java
* Written by Team 3: Christian Wittner, Ivan Dimitrov
*
* This code has been developed at the Karlsruhe Institute of Technology (KIT), Germany,
* as part of the course "Multicore Programming in Practice: Tools, Models, and Languages".
* Contact instructor: Dr. Victor Pankratius (pankratius@ipd.uka.de)
*
* Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
*
* Electric(tm) is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* Electric(tm) is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Electric(tm); see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, Mass 02111-1307, USA.
*/
package com.sun.electric.tool.placement.genetic1.g1;
import com.sun.electric.tool.placement.genetic1.Chromosome;
import com.sun.electric.tool.placement.genetic1.ChromosomeMutation;
import java.util.Random;
public class ChromosomeMutationPadding implements ChromosomeMutation {
static int nbrOfPlaceHoldersToMutate = -1;
static short maxChangePerStep;
public ChromosomeMutationPadding(short maxChangePerStep) {
ChromosomeMutationPadding.maxChangePerStep = maxChangePerStep;
}
public void mutate(Chromosome c, Random r) {
assert (nbrOfPlaceHoldersToMutate > -1) : "set nbr of placeholders before using mutation";
int indexOfPlaceholder;
for (int i = 0; i < nbrOfPlaceHoldersToMutate; i++) {
// resize placeholder
indexOfPlaceholder = r.nextInt(c.GeneXPadding.length);
// change x
if (r.nextBoolean()) {
c.GeneXPadding[indexOfPlaceholder] += r
.nextInt(maxChangePerStep);
if (c.GeneXPadding[indexOfPlaceholder] < 0)
c.GeneXPadding[indexOfPlaceholder] = 0;
}
// or change y
else {
c.GeneYPadding[indexOfPlaceholder] += r
.nextInt(maxChangePerStep);
if (c.GeneYPadding[indexOfPlaceholder] < 0)
c.GeneYPadding[indexOfPlaceholder] = 0;
}
}
}
public void setMutationRate(double mutationRate) {
nbrOfPlaceHoldersToMutate = (int) (GeneticPlacement.nodeProxies.length * mutationRate);
if (nbrOfPlaceHoldersToMutate < 1)
nbrOfPlaceHoldersToMutate = 1;
}
}