math.MathConsts Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of finwhale Show documentation
Statistical distributions library (in statu nascendi)
The newest version!
/*
 * Copyright 2013 SPZ
 *
 * 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 math;

/**
 * Some numerical constants from the Cephes library.
 */
public final class MathConsts {

    /** The IEEE 754 machine epsilon from Cephes: {@code (2^-53)} */
    public static final double MACH_EPS = 1.11022302462515654042e-16;

    /** 7.09782712893383996732e2 */
    public static final double MAX_LOG = 7.09782712893383996732e2;

    /** -7.451332191019412076235e2 */
    public static final double MIN_LOG = -7.451332191019412076235e2;

    /** 171.624376956302725 */
    public static final double MAX_GAMMA = 171.624376956302725;

    /** The value of {@code sqrt(2)} */
    public static final double SQRT_TWO = 1.41421356237309504880e0;

    /** The value of {@code sqrt(2*PI)} */
    public static final double SQRT_TWO_PI = 2.50662827463100050242e0;

    /** The value of {@code sqrt(PI/2)} */
    public static final double SQRT_PI_HALF = 1.2533141373155001e0;

    /** The value of {@code sqrt(2)/2} */
    public static final double SQRT_TWO_HALF = 7.07106781186547524401e-1;

    /** The value of {@code Math.PI * Math.PI} (9.869604401089358) */
    public static final double PI_SQUARED = Math.PI * Math.PI;

    /** The value of {@code ln(PI)} */
    public static final double LN_PI = 1.14472988584940017414; /* ln(PI) */

    /** The value of {@code ln2} */
    public static final double LN_2 = 0.69314718055994530941; /* ln(2) */

    /** The value of {@code ln(10)} */
    public static final double LN_10 = 2.302585092994046; /* ln(10) */

    /** 4.503599627370496e15 */
    public static final double BIG = 4.503599627370496e15;

    /** 2.22044604925031308085e-16 */
    public static final double BIG_INV = 2.22044604925031308085e-16;

    /** 4.450147717014403e-308 (equals 2 x {@link Double#MIN_NORMAL}) */
    public static final double MIN_VAL = 2.0 * Double.MIN_NORMAL;

    /** Natural logarithm of {@link Double#MIN_NORMAL} (-708.3964185322641) */
    public static final double LN_MIN_NORMAL = -708.3964185322641;

    /**
     * 5.218048215738236e-15 (equals (45 x {@link #MACH_EPS}) +
     * {@link #BIG_INV})
     */
    public static final double MIN_TOL = (45.0 * MACH_EPS) + BIG_INV;

    /**
     * Largest int x such that 10^x is representable (approximately) as double
     */
    public static final int MAX_X_FOR_10_EXP_X_AS_DOUBLE = 308;

    private MathConsts() {
    }
}