/**
* diqube: Distributed Query Base.
*
* Copyright (C) 2015 Bastian Gloeckle
*
* This file is part of diqube.
*
* diqube 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 org.diqube.function.projection;
import org.apache.commons.math3.util.FastMath;
import org.diqube.data.column.ColumnType;
import org.diqube.function.Function;
/**
* Calculate logarithm to base e of a double.
*
* @author Bastian Gloeckle
*/
@Function(name = LogDoubleFunction.NAME)
public class LogDoubleFunction extends AbstractSingleParamProjectionFunction<Double, Double> {
public static final String NAME = "log";
public LogDoubleFunction() {
super(NAME, ColumnType.DOUBLE, ColumnType.DOUBLE, LogDoubleFunction::log);
}
public static double log(Double l) {
return FastMath.log(l);
}
}