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/*
* ******************************************************************************
* *
* *
* * This program and the accompanying materials are made available under the
* * terms of the Apache License, Version 2.0 which is available at
* * https://www.apache.org/licenses/LICENSE-2.0.
* *
* * See the NOTICE file distributed with this work for additional
* * information regarding copyright ownership.
* * Unless required by applicable law or agreed to in writing, software
* * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* * License for the specific language governing permissions and limitations
* * under the License.
* *
* * SPDX-License-Identifier: Apache-2.0
* *****************************************************************************
*/
package org.nd4j.linalg.indexing;
import lombok.Data;
import lombok.extern.slf4j.Slf4j;
import net.ericaro.neoitertools.Generator;
import net.ericaro.neoitertools.Itertools;
import org.nd4j.linalg.api.ndarray.INDArray;
import org.nd4j.linalg.util.LongUtils;
import java.util.Arrays;
import java.util.List;
import java.util.NoSuchElementException;
/**
*
* A SpecifiedIndex refers to a concrete set of points
* to be selectively pulled from a given dimension.
*
* Note that using this index will always trigger a copy.
*
* Pulling random indices from an array wil not allow a view to be computed.
* Negative indices can also be specified allowing for dynamic
* resolution of dimensions/coordinates at runtime.
*
* @author Adam Gibson
*/
@Data
@Slf4j
public class SpecifiedIndex implements INDArrayIndex {
private long[] indexes;
private boolean initialized = false;
public SpecifiedIndex(int... indexes) {
this.indexes = LongUtils.toLongs(indexes);
}
public SpecifiedIndex(long... indexes) {
this.indexes = indexes;
}
@Override
public long end() {
return indexes[indexes.length - 1];
}
@Override
public long offset() {
return indexes[0];
}
@Override
public long length() {
return indexes.length;
}
@Override
public long stride() {
return 1;
}
@Override
public void reverse() {
}
@Override
public boolean isInterval() {
return false;
}
@Override
public void init(INDArray arr, long begin, int dimension) {
}
@Override
public void init(INDArray arr, int dimension) {
if(indexes != null) {
for(int i = 0; i < indexes.length; i++) {
if(indexes[i] < 0) {
indexes[i] += arr.size(dimension);
}
}
initialized = true;
}
}
@Override
public void init(long begin, long end, long max) {
}
@Override
public void init(long begin, long end) {
}
@Override
public boolean initialized() {
boolean initialized = indexes != null;
if(indexes != null)
for(int i = 0; i < indexes.length; i++) {
if(indexes[i] < 0) {
return false;
}
}
return this.initialized && initialized;
}
@Override
public INDArrayIndex dup() {
SpecifiedIndex specifiedIndex = new SpecifiedIndex();
specifiedIndex.initialized = initialized;
specifiedIndex.indexes = Arrays.copyOf(indexes,indexes.length);
return this;
}
/**
* Iterate over a cross product of the
* coordinates
* @param indexes the coordinates to iterate over.
* Each element of the array should be of opType {@link SpecifiedIndex}
* otherwise it will end up throwing an exception
* @return the generator for iterating over all the combinations of the specified indexes.
*/
public static Generator>> iterate(INDArrayIndex... indexes) {
Generator>> gen = Itertools.product(new SpecifiedIndexesGenerator(indexes));
return gen;
}
/**
* Iterate over a cross product of the
* coordinates
* @param indexes the coordinates to iterate over.
* Each element of the array should be of opType {@link SpecifiedIndex}
* otherwise it will end up throwing an exception
* @return the generator for iterating over all the combinations of the specified indexes.
*/
public static Generator>> iterateOverSparse(INDArrayIndex... indexes) {
Generator>> gen = Itertools.product(new SparseSpecifiedIndexesGenerator(indexes));
return gen;
}
/**
* A generator for {@link SpecifiedIndex} for
* {@link Itertools#product(Generator)}
* to iterate
over an array given a set of iterators
*/
public static class SpecifiedIndexesGenerator implements Generator>> {
private int index = 0;
private INDArrayIndex[] indexes;
/**
* The indexes to generate from
* @param indexes the indexes to generate from
*/
public SpecifiedIndexesGenerator(INDArrayIndex[] indexes) {
this.indexes = indexes;
for(int i=0; i> next() throws NoSuchElementException {
if (index >= indexes.length) {
throw new NoSuchElementException("Done");
}
SpecifiedIndex specifiedIndex = (SpecifiedIndex) indexes[index++];
Generator> ret = specifiedIndex.generator();
return ret;
}
}
/**
* A generator for {@link SpecifiedIndex} for
* {@link Itertools#product(Generator)}
* to iterate
over an array given a set of iterators
*/
public static class SparseSpecifiedIndexesGenerator implements Generator>> {
private int index = 0;
private INDArrayIndex[] indexes;
/**
* The indexes to generate from
* @param indexes the indexes to generate from
*/
public SparseSpecifiedIndexesGenerator(INDArrayIndex[] indexes) {
this.indexes = indexes;
}
@Override
public Generator> next() throws NoSuchElementException {
if (index >= indexes.length) {
throw new NoSuchElementException("Done");
}
SpecifiedIndex specifiedIndex = (SpecifiedIndex) indexes[index++];
Generator> ret = specifiedIndex.sparseGenerator();
return ret;
}
}
public class SingleGenerator implements Generator> {
/**
* @return the next item in the sequence.
* @throws NoSuchElementException when sequence is exhausted.
*/
@Override
public List next() throws NoSuchElementException {
// if (!SpecifiedIndex.this.hasNext())
// throw new NoSuchElementException();
//
// return Longs.asList(SpecifiedIndex.this.next());
throw new RuntimeException();
}
}
public class SparseSingleGenerator implements Generator> {
/**
* @return the next item in the sequence.
* @throws NoSuchElementException when sequence is exhausted.
*/
@Override
public List next() throws NoSuchElementException {
// if (!SpecifiedIndex.this.hasNext())
// throw new NoSuchElementException();
// long[] pair = SpecifiedIndex.this.nextSparse();
// return Arrays.asList(pair[0], pair[1]);
throw new RuntimeException();
}
}
public Generator> generator() {
return new SingleGenerator();
}
public Generator> sparseGenerator() {
return new SparseSingleGenerator();
}
}