ucar.nc2.iosp.hdf5.Tiling Maven / Gradle / Ivy
Show all versions of netcdf Show documentation
/*
* Copyright 1998-2009 University Corporation for Atmospheric Research/Unidata
*
* Portions of this software were developed by the Unidata Program at the
* University Corporation for Atmospheric Research.
*
* Access and use of this software shall impose the following obligations
* and understandings on the user. The user is granted the right, without
* any fee or cost, to use, copy, modify, alter, enhance and distribute
* this software, and any derivative works thereof, and its supporting
* documentation for any purpose whatsoever, provided that this entire
* notice appears in all copies of the software, derivative works and
* supporting documentation. Further, UCAR requests that the user credit
* UCAR/Unidata in any publications that result from the use of this
* software or in any product that includes this software. The names UCAR
* and/or Unidata, however, may not be used in any advertising or publicity
* to endorse or promote any products or commercial entity unless specific
* written permission is obtained from UCAR/Unidata. The user also
* understands that UCAR/Unidata is not obligated to provide the user with
* any support, consulting, training or assistance of any kind with regard
* to the use, operation and performance of this software nor to provide
* the user with any updates, revisions, new versions or "bug fixes."
*
* THIS SOFTWARE IS PROVIDED BY UCAR/UNIDATA "AS IS" AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL UCAR/UNIDATA BE LIABLE FOR ANY SPECIAL,
* INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
* FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
* WITH THE ACCESS, USE OR PERFORMANCE OF THIS SOFTWARE.
*/
package ucar.nc2.iosp.hdf5;
/**
* A Tiling divides a multidimensional index into tiles.
* Abstraction of HDF5 chunking.
*
* Index are points in the original multidimensional index.
* Tiles are points in the tiled space.
*
* Each tile has the same size, given by tileSize.
*
* @author caron
* @since Jul 20, 2007
*/
public class Tiling {
private int rank;
private int[] shape, tileSize, tile, stride;
/**
* Create a Tiling
* @param shape overall shape of the dataset's index space
* @param tileSize tile size. may be larger than the shape.
*/
public Tiling(int[] shape, int[] tileSize) {
assert shape.length <= tileSize.length; // convenient to allow tileSize to have (an) extra dimension at the end
// to accomodate hdf5 storage, which has the element size
this.rank = shape.length;
this.tileSize = tileSize;
this.shape = new int[rank];
for (int i=0; i= 0; k--) {
stride[k] = strider;
strider *= tile[k];
}
}
/**
* Compute the tile
* @param pt index point
* @return corresponding tile
*/
public int[] tile(int[] pt) {
// assert pt.length == rank;
int[] tile = new int[rank];
for (int i = 0; i < rank; i++) {
if (shape[i] < pt[i])
System.out.println("HEY shape[i] < pt[i]");
assert shape[i] >= pt[i];
tile[i] = pt[i] / tileSize[i];
}
return tile;
}
/**
* Get order based on which tile the pt belongs to
* @param pt index point
* @return order number based on which tile the pt belongs to
*/
public int order(int[] pt) {
int[] tile = tile(pt);
int order = 0;
for (int i = 0; i < rank; i++)
order += stride[i] * tile[i];
return order;
}
/**
* Create an ordering of index points based on which tile the point is in.
* @param p1 index point 1
* @param p2 index point 2
* @return order(p1) - order(p2) : negetive if p1 < p2, positive if p1 > p2 , 0 if equal
*/
public int compare(int[] p1, int[] p2) {
return order(p1) - order(p2);
}
}