org.nd4j.linalg.indexing.IntervalIndex Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2015-2018 Skymind, Inc.
*
* 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.
*
* 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 com.google.common.primitives.Longs;
import org.nd4j.linalg.api.ndarray.INDArray;
/**
* And indexing representing
* an interval
*
* @author Adam Gibson
*/
public class IntervalIndex implements INDArrayIndex {
protected long begin, end;
protected boolean inclusive;
protected long stride = 1;
protected long index = 0;
protected long length = 0;
/**
*
* @param inclusive whether to include the last number
* @param stride the stride for the interval
*/
public IntervalIndex(boolean inclusive, long stride) {
this.inclusive = inclusive;
this.stride = stride;
this.length = (int) Math.abs((end - begin)) / stride;
}
@Override
public long end() {
return end;
}
@Override
public long offset() {
return begin;
}
@Override
public long length() {
return length;
}
@Override
public long stride() {
return stride;
}
@Override
public long current() {
return index;
}
@Override
public boolean hasNext() {
return index < end();
}
@Override
public long next() {
long ret = index;
index += stride;
return ret;
}
@Override
public void reverse() {
long oldEnd = end;
long oldBegin = begin;
this.end = oldBegin;
this.begin = oldEnd;
}
@Override
public boolean isInterval() {
return true;
}
@Override
public void setInterval(boolean isInterval) {
//no-op
}
@Override
public void init(INDArray arr, long begin, int dimension) {
if(begin < 0) {
begin += arr.size(dimension);
}
this.begin = begin;
this.index = begin;
this.end = inclusive ? arr.size(dimension) + 1 : arr.size(dimension);
for (long i = begin; i < end; i += stride) {
length++;
}
}
@Override
public void init(INDArray arr, int dimension) {
init(arr, 0, dimension);
}
@Override
public void init(long begin, long end, long max) {
if(begin < 0) {
begin += max;
}
if(end < 0) {
end += max;
}
this.begin = begin;
this.index = begin;
this.end = inclusive ? end + 1 : end;
for (long i = begin; i < this.end; i += stride) {
length++;
}
}
@Override
public void init(long begin, long end) {
if(begin < 0 || end < 0)
throw new IllegalArgumentException("Please pass in an array for negative indices. Unable to determine size for dimension otherwise");
this.begin = begin;
this.index = begin;
this.end = inclusive ? end + 1 : end;
for (long i = begin; i < this.end; i += stride) {
length++;
}
}
@Override
public void reset() {
}
@Override
public boolean equals(Object o) {
if (this == o)
return true;
if (!(o instanceof IntervalIndex))
return false;
IntervalIndex that = (IntervalIndex) o;
if (begin != that.begin)
return false;
if (end != that.end)
return false;
if (inclusive != that.inclusive)
return false;
if (stride != that.stride)
return false;
return index == that.index;
}
@Override
public int hashCode() {
int result = Longs.hashCode(begin);
result = 31 * result + Longs.hashCode(end);
result = 31 * result + (inclusive ? 1 : 0);
result = 31 * result + Longs.hashCode(stride);
result = 31 * result + Longs.hashCode(index);
return result;
}
}