/*
* Encog(tm) Core v3.4 - Java Version
* http://www.heatonresearch.com/encog/
* https://github.com/encog/encog-java-core
* Copyright 2008-2016 Heaton Research, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://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.
*
* For more information on Heaton Research copyrights, licenses
* and trademarks visit:
* http://www.heatonresearch.com/copyright
*/
package org.encog.util.arrayutil;
import java.util.ArrayList;
import java.util.List;
import org.encog.EncogError;
import org.encog.util.EngineArray;
/**
* Create a sliding window of double arrays. New vectors can be added to the
* window. Once the required number of vectors have been added then the entire
* window can be copied to an output vector large enough to hold it.
*/
public class VectorWindow {
/**
* The window.
*/
private final List<double[]> window = new ArrayList<double[]>();
/**
* The number of slices in a window.
*/
private final int sliceCount;
/**
* Construct a sliding window.
* @param theSliceCount The number of slices in a window.
*/
public VectorWindow(int theSliceCount) {
this.sliceCount = theSliceCount;
}
/**
* Add a single vector to the window.
* @param vec The vector to add to the window.
*/
public void add(double[] vec) {
this.window.add(vec.clone());
while (this.window.size() > this.sliceCount) {
this.window.remove(0);
}
}
/**
* @return True, if we've added enough slices for a complete window.
*/
public boolean isReady() {
return this.window.size() >= this.sliceCount;
}
/**
* Copy the entire window to a complete vector.
* @param output The vector to copy to.
* @param startPos The starting position to write to.
*/
public void copyWindow(double[] output, int startPos) {
if (!isReady()) {
throw new EncogError("Can't produce a timeslice of size "
+ this.sliceCount + ", there are only "
+ this.window.size() + " vectors loaded.");
}
int currentIndex = startPos;
for (int i = 0; i < this.window.size(); i++) {
double[] source = this.window.get(i);
EngineArray.arrayCopy(source, 0, output, currentIndex,
source.length);
currentIndex += source.length;
}
}
}