com.vividsolutions.jts.math.MathUtil Maven / Gradle / Ivy
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/*
* The JTS Topology Suite is a collection of Java classes that
* implement the fundamental operations required to validate a given
* geo-spatial data set to a known topological specification.
*
* Copyright (C) 2001 Vivid Solutions
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* For more information, contact:
*
* Vivid Solutions
* Suite #1A
* 2328 Government Street
* Victoria BC V8T 5G5
* Canada
*
* (250)385-6040
* www.vividsolutions.com
*/
package com.vividsolutions.jts.math;
/**
* Various utility functions for mathematical and numerical operations.
*
* @author mbdavis
*
*/
public class MathUtil
{
/**
* Clamps a double value to a given range.
* @param x the value to clamp
* @param min the minimum value of the range
* @param max the maximum value of the range
* @return the clamped value
*/
public static double clamp(double x, double min, double max)
{
if (x < min) return min;
if (x > max) return max;
return x;
}
/**
* Clamps an int value to a given range.
* @param x the value to clamp
* @param min the minimum value of the range
* @param max the maximum value of the range
* @return the clamped value
*/
public static int clamp(int x, int min, int max)
{
if (x < min) return min;
if (x > max) return max;
return x;
}
private static final double LOG_10 = Math.log(10);
/**
* Computes the base-10 logarithm of a double value.
*
* - If the argument is NaN or less than zero, then the result is NaN.
*
- If the argument is positive infinity, then the result is positive infinity.
*
- If the argument is positive zero or negative zero, then the result is negative infinity.
*
*
* @param x a positive number
* @return the value log a, the base-10 logarithm of the input value
*/
public static double log10(double x)
{
double ln = Math.log(x);
if (Double.isInfinite(ln)) return ln;
if (Double.isNaN(ln)) return ln;
return ln / LOG_10;
}
/**
* Computes an index which wraps around a given maximum value.
* For values >= 0, this is equals to val % max.
* For values < 0, this is equal to max - (-val) % max
*
* @param index the value to wrap
* @param max the maximum value (or modulus)
* @return the wrapped index
*/
public static int wrap(int index, int max)
{
if (index < 0) {
return max - ((-index) % max);
}
return index % max;
}
/**
* Computes the average of two numbers.
*
* @param x1 a number
* @param x2 a number
* @return the average of the inputs
*/
public static double average(double x1, double x2)
{
return (x1 + x2) / 2.0;
}
public static double max(double v1, double v2, double v3)
{
double max = v1;
if (v2 > max) max = v2;
if (v3 > max) max = v3;
return max;
}
public static double max(double v1, double v2, double v3, double v4)
{
double max = v1;
if (v2 > max) max = v2;
if (v3 > max) max = v3;
if (v4 > max) max = v4;
return max;
}
public static double min(double v1, double v2, double v3, double v4)
{
double min = v1;
if (v2 < min) min = v2;
if (v3 < min) min = v3;
if (v4 < min) min = v4;
return min;
}
}