/**
* Copyright (C) 2001-2017 by RapidMiner and the contributors
*
* Complete list of developers available at our web site:
*
* http://rapidminer.com
*
* This program is free software: you can redistribute it and/or modify it under the terms of the
* GNU Affero General Public License as published by the Free Software Foundation, either version 3
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
* even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License along with this program.
* If not, see http://www.gnu.org/licenses/.
*/
package com.rapidminer.tools.math.function.aggregation;
/**
* Calculates the standard deviation.
*
* @author Tobias Malbrecht
*
*/
public class StandardDeviationFunction extends VarianceFunction {
public StandardDeviationFunction() {
this(DEFAULT_IGNORE_MISSINGS);
}
public StandardDeviationFunction(Boolean ignoreMissings) {
super(ignoreMissings);
}
@Override
public String getName() {
return "standard_deviation";
}
@Override
public double getValue() {
// return the square root of the variance
double value = super.getValue();
if (value > 0) {
return Math.sqrt(value);
}
return 0d;
}
}