// $Id: FlipMap.java,v 1.2 2002-05-29 20:32:39 steve Exp $
/*
* Copyright 1997-2000 Unidata Program Center/University Corporation for
* Atmospheric Research, P.O. Box 3000, Boulder, CO 80307,
* support@unidata.ucar.edu.
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or (at
* your option) any later version.
*
* This library 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 Lesser
* General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package ucar.multiarray;
import java.lang.reflect.Array;
/**
* Use with MultiArrayProxy to flip (invert) the
* indexing along a particular dimension.
* Maps {0, 1, ..., N-1} to {N-1, N-2, ..., 0} where
* N is the length of the dimension.
*
* @see IndexMap
* @see MultiArrayProxy
*
* @author $Author: steve $
* @version $Revision: 1.2 $ $Date: 2002-05-29 20:32:39 $
*/
public class
FlipMap
extends ConcreteIndexMap
{
/**
* Create an IndexMap which flips the indexing
* for a particular dimension.
*
* @param position the dimension number where the index
* is to be flipped.
*/
public
FlipMap(int position)
{
init(new IMap());
position_ = position;
}
/**
* Create an IndexMap which flips the indexing
* for a particular dimension and is functionally composed
* with another IndexMap.
*
* @param prev ConcreteIndexMap to be composed with this.
* @param position the dimension number where the index
* is to be flipped.
*/
public
FlipMap(ConcreteIndexMap prev, int position)
{
link(prev, new IMap());
position_ = position;
}
private class
IMap extends ZZMap
{
public synchronized int
get(int key)
{
final int value = super.get(key);
if(key == position_)
return (lengthsMap_.get(key) -1 - value);
// else
return value;
}
}
/* WORKAROUND: Inner class & blank final initialize compiler bug */
private /* final */ int position_;
/* Begin Test */
public static void
main(String[] args)
{
final int [] shape = {48, 64};
MultiArrayImpl delegate =
new MultiArrayImpl(Integer.TYPE, shape);
{
final int size = MultiArrayImpl.numberOfElements(shape);
for(int ii = 0; ii < size; ii++)
java.lang.reflect.Array.setInt(delegate.storage,
ii, ii);
}
IndexMap im = new FlipMap(1);
MultiArray ma = new MultiArrayProxy(delegate, im);
try {
System.out.println("Rank " + ma.getRank());
int [] lengths = ma.getLengths();
System.out.println("Shape { " + lengths[0]
+ " " + lengths[1] + " }");
System.out.println(ma.getInt(new int[] {0, 0}));
}
catch (java.io.IOException ee) {}
}
/* Test output java ucar.multiarray.FlipMap
Rank 2
Shape { 48 64 }
63
*/
/* End Test */
}