// $Id: FlattenMap.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 reduce apparent rank by
* merging adjacent dimensions. The total number of elements
* remains constant.
* <p>
* This framework doesn't really support this operation
* very well. See caveats in <code>get()</code>
*
* @see IndexMap
* @see MultiArrayProxy
*
* @author $Author: steve $
* @version $Revision: 1.2 $ $Date: 2002-05-29 20:32:39 $
*/
public class
FlattenMap
extends ConcreteIndexMap
{
/**
* Create an ConcreteIndexMap which merges two adjacent dimensions.
* Using this in an MultiArrayProxy will result in the
* a MultiArray of one less rank.
* @param position this dimension and
* dimension <code>(position +1)</code>
* will appear as a single dimension.
*/
public
FlattenMap(int position)
{
init(new IMap(),
new LengthsMap());
position_ = position;
}
/**
* Create an ConcreteIndexMap which merges two adjacent dimensions.
* Using this in an MultiArrayProxy will result in the
* a MultiArray of one less rank.
* @param prev ConcreteIndexMap to be composed with this.
* @param position this dimension and
* dimension <code>(position +1)</code>
*/
public
FlattenMap(ConcreteIndexMap prev, int position)
{
link(prev, new IMap(),
new LengthsMap());
position_ = position;
}
private class
IMap extends ZZMap
{
public synchronized int
get(int key)
{
if(key < position_)
return super.get(key);
if(key == position_)
{
length_ = ((LengthsMap)lengthsMap_)
.superGet(key + 1);
final int got = super.get(key);
value_ = got % length_;
return got / length_;
}
if(key == position_ +1)
return value_;
// else
return super.get(key - 1);
}
public synchronized int
size()
{
return super.size() +1;
}
private int length_;
private int value_;
}
private class
LengthsMap extends ZZMap
{
public synchronized int
get(int key)
{
if(key < position_)
return super.get(key);
// else
if(key == position_)
return super.get(key) *
super.get(key + 1);
// else
return super.get(key +1);
}
public synchronized int
size()
{
return super.size() -1;
}
int
superGet(int key)
{
return super.get(key);
}
}
/**/
/* WORKAROUND: Inner class & blank final initialize compiler bug */
private /* final */ int position_;
/* Begin Test */
public static void
main(String[] args)
{
final int [] shape = {32, 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);
}
ConcreteIndexMap im = new FlattenMap(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}));
System.out.println(ma.getInt(new int[] {0, 1}));
System.out.println(ma.getInt(new int[] {0, 63}));
System.out.println(ma.getInt(new int[] {0, 64}));
System.out.println(ma.getInt(new int[] {0, 3071}));
System.out.println(ma.getInt(new int[] {1, 0}));
}
catch (java.io.IOException ee) {}
}
/* Test output java ucar.multiarray.FlattenMap
Rank 2
Shape { 32, 3072 }
0
1
63
64
3071
3072
*/
/* End Test */
}