/*******************************************************************************
* Copyright 2015 Analog Devices, 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.
********************************************************************************/
package com.analog.lyric.dimple.data;
/**
* Specifies density of representation for {@link DataLayer} classes.
* <p>
* Used in constructors of {@link DataLayer} and {@link FactorGraphData} classes.
* <p>
* @since 0.08
* @author Christopher Barber
*/
public enum DataDensity
{
/**
* Specifies a sparse hash-table based representation.
* <p>
* This holds all data values in a hash table for each factor graph. Getting/setting is constant time
* but slower than the DENSE representation. It requires O(V) memory where V are the number of data
* values actually stored in the layer.
*/
SPARSE,
/**
* Specifies a dense array-based representation.
* <p>
* This holds all data values in an array for each factor graph, so getting/setting only costs
* a couple of array accesses. It requires O(K) memory where K is the number of keys.
*/
DENSE;
}