FM / geometry-library

/home/desid573/phewl.desidrivers.com.au/geometry-library/

/home/desid573/phewl.desidrivers.com.au/geometry-library

Name	Size	Mode	Actions
composer.json	882	0644	edit dl rm
LICENSE	1086	0644	edit dl rm
MathUtil.php	3325	0644	edit dl rm
PolyUtil.php	15103	0644	edit dl rm
README.md	15261	0644	edit dl rm
SphericalUtil.php	10225	0644	edit dl rm

Edit: /home/desid573/phewl.desidrivers.com.au/geometry-library/MathUtil.php (3325B)

<?php namespace GeometryLibrary;

/*
 * Copyright 2013 Google Inc.
 * https://github.com/googlemaps/android-maps-utils/blob/master/library/src/com/google/maps/android/MathUtil.java
 * 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.
 */

class MathUtil {
  /**
     * The earth's radius, in meters.
     * Mean radius as defined by IUGG.
     */
    const EARTH_RADIUS = 6371009;

/**
     * Restrict x to the range [low, high].
     */
    public static function clamp( $x, $low, $high) {
        return $x < $low ? $low : ($x > $high ? $high : $x);
    }
    
    /**
     * Wraps the given value into the inclusive-exclusive interval between min and max.
     * @param n   The value to wrap.
     * @param min The minimum.
     * @param max The maximum.
     */
    public static function wrap($n, $min, $max) {
        return ($n >= $min && $n < $max) ? $n : (self::mod($n - $min, $max - $min) + $min);
    }

/**
     * Returns the non-negative remainder of x / m.
     * @param x The operand.
     * @param m The modulus.
     */
    public static function mod($x, $m) {
        return (($x % $m) + $m) % $m;
    }

/**
     * Returns mercator Y corresponding to latitude.
     * See http://en.wikipedia.org/wiki/Mercator_projection .
     */
    public static function mercator($lat) {
        return log(tan($lat * 0.5 + M_PI/4));
    }

/**
     * Returns latitude from mercator Y.
     */
    public static function inverseMercator($y) {
        return 2 * atan(exp($y)) - M_PI / 2;
    }
    
    /**
     * Returns haversine(angle-in-radians).
     * hav(x) == (1 - cos(x)) / 2 == sin(x / 2)^2.
     */
    public static function hav($x) {
        $sinHalf = sin($x * 0.5);
        return $sinHalf * $sinHalf;
    }

/**
     * Computes inverse haversine. Has good numerical stability around 0.
     * arcHav(x) == acos(1 - 2 * x) == 2 * asin(sqrt(x)).
     * The argument must be in [0, 1], and the result is positive.
     */
    public static function arcHav($x) {
        return 2 * asin(sqrt($x));
    }
    
    // Given h==hav(x), returns sin(abs(x)).
    public static function sinFromHav($h) {
        return 2 * sqrt($h * (1 - $h));
    }

// Returns hav(asin(x)).
    public static function havFromSin($x) {
        $x2 = $x * $x;
        return $x2 / (1 + sqrt(1 - $x2)) * .5;
    }

// Returns sin(arcHav(x) + arcHav(y)).
    public static function sinSumFromHav($x, $y) {
        $a = sqrt($x * (1 - $x));
        $b = sqrt($y * (1 - $y));
        return 2 * ($a + $b - 2 * ($a * $y + $b * $x));
    }

/**
     * Returns hav() of distance from (lat1, lng1) to (lat2, lng2) on the unit sphere.
     */
    public static function havDistance($lat1, $lat2, $dLng) {
        return self::hav($lat1 - $lat2) + self::hav($dLng) * cos($lat1) * cos($lat2);
    }
}

$high ? $high : $x); } /** * Wraps the given value into the inclusive-exclusive interval between min and max. * @param n The value to wrap. * @param min The minimum. * @param max The maximum. */ public static function wrap($n, $min, $max) { return ($n >= $min && $n < $max) ? $n : (self::mod($n - $min, $max - $min) + $min); } /** * Returns the non-negative remainder of x / m. * @param x The operand. * @param m The modulus. */ public static function mod($x, $m) { return (($x % $m) + $m) % $m; } /** * Returns mercator Y corresponding to latitude. * See http://en.wikipedia.org/wiki/Mercator_projection . */ public static function mercator($lat) { return log(tan($lat * 0.5 + M_PI/4)); } /** * Returns latitude from mercator Y. */ public static function inverseMercator($y) { return 2 * atan(exp($y)) - M_PI / 2; } /** * Returns haversine(angle-in-radians). * hav(x) == (1 - cos(x)) / 2 == sin(x / 2)^2. */ public static function hav($x) { $sinHalf = sin($x * 0.5); return $sinHalf * $sinHalf; } /** * Computes inverse haversine. Has good numerical stability around 0. * arcHav(x) == acos(1 - 2 * x) == 2 * asin(sqrt(x)). * The argument must be in [0, 1], and the result is positive. */ public static function arcHav($x) { return 2 * asin(sqrt($x)); } // Given h==hav(x), returns sin(abs(x)). public static function sinFromHav($h) { return 2 * sqrt($h * (1 - $h)); } // Returns hav(asin(x)). public static function havFromSin($x) { $x2 = $x * $x; return $x2 / (1 + sqrt(1 - $x2)) * .5; } // Returns sin(arcHav(x) + arcHav(y)). public static function sinSumFromHav($x, $y) { $a = sqrt($x * (1 - $x)); $b = sqrt($y * (1 - $y)); return 2 * ($a + $b - 2 * ($a * $y + $b * $x)); } /** * Returns hav() of distance from (lat1, lng1) to (lat2, lng2) on the unit sphere. */ public static function havDistance($lat1, $lat2, $dLng) { return self::hav($lat1 - $lat2) + self::hav($dLng) * cos($lat1) * cos($lat2); } } ?>