/**
* 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.gui.plotter;
import java.text.DecimalFormat;
/**
* Transforms the given value by applying a log function.
*
* @author Ingo Mierswa
*/
public class AxisTransformationLog implements AxisTransformation {
private DecimalFormat format = new DecimalFormat("0.00E0");
/** Transforms the given value by applying a log function. */
@Override
public double transform(double value) {
if (value <= 0.0d) {
throw new IllegalArgumentException("Cannot apply log scaling to a value less than or equal to zero.");
}
return Math.log10(value);
}
/** Transforms the given value by applying an exponential function. */
@Override
public double inverseTransform(double value) {
return Math.pow(10, value);
}
/** Returns the formatted value. Returns null if the value does not start with 1. */
@Override
public String format(double value, int formatNumber) {
if (formatNumber % 2 == 0) {
return format.format(value);
} else {
return null;
}
}
/** Adapts the minimum corresponding to the given tic size. */
@Override
public double adaptTicsMin(double min, double ticSize) {
return min;
}
/** Adapts the maximum corresponding to the given tic size. */
@Override
public double adaptTicsMax(double max, double ticSize) {
return max;
}
}