php Programming Glossary: sqrt
Measuring the distance between two coordinates in PHP http://stackoverflow.com/questions/10053358/measuring-the-distance-between-two-coordinates-in-php this lat_b sin deg2rad beta sin deg2rad beta c asin min 1 sqrt a distance 2 earth_radius c distance round distance 4 this.. latDelta latTo latFrom lonDelta lonTo lonFrom angle 2 asin sqrt pow sin latDelta 2 2 cos latFrom cos latTo pow sin lonDelta..
How to evaluate formula passed as string in PHP? http://stackoverflow.com/questions/1015242/how-to-evaluate-formula-passed-as-string-in-php negation built in functions result m evaluate ' 8 5 2 ^2 1 sqrt 4 8' create your own variables m evaluate 'a e^ ln pi ' or functions.. 'acosh' 'tan' 'tanh' 'arctan' 'atan' 'arctanh' 'atanh' 'sqrt' 'abs' 'ln' 'log' function EvalMath make the variables a little..
How do I check if a longitude/latitude point is within a range of coordinates? http://stackoverflow.com/questions/11510326/how-do-i-check-if-a-longitude-latitude-point-is-within-a-range-of-coordinates tan lat y x tan long z x the Vector has magnitude 1 so sqrt x^2 y^2 z^2 1 rearrange some symbols solving for x first..... some symbols solving for x first... ret.x 1.0 math.sqrt tan c.lattitude ^2 tan c.longitude ^2 1 then for y and z ret.y.. other.y this.z other.z double Vector Magnitude return math.sqrt this.x^2 this.y^2 this.z^2 for any two vectors `a` and `b` a.DotProduct..
Formulas to Calculate Geo Proximity http://stackoverflow.com/questions/2096385/formulas-to-calculate-geo-proximity are law of cosines 5 trig. calls haversine involves sqrt Vicenty have to solve this iteratively in a for loop Which one.. in longitude y ky difference in latitude. Then distance sqrt dx dx dy dy . If your problem domain is such that it can be.. solved with distance squared then you won't have to take sqrt and this formula will be as fast as you get possibly get. It..
php mysql compare long and lat, return ones under 10 miles http://stackoverflow.com/questions/2296824/php-mysql-compare-long-and-lat-return-ones-under-10-miles dlat 2 cos lat1 cos lat2 sin dlng 2 sin dlng 2 c 2 atan2 sqrt a sqrt 1 a km r c return floor km 0.621371192 This one returns.. 2 cos lat1 cos lat2 sin dlng 2 sin dlng 2 c 2 atan2 sqrt a sqrt 1 a km r c return floor km 0.621371192 This one returns a bool..
Generate Random Numbers with Probabilistic Distribution http://stackoverflow.com/questions/3109670/generate-random-numbers-with-probabilistic-distribution I had was to square the random number between 0 and sqrt 70 . But that would favor both less than 1 and larger numbers...
PHP MySql and geolocation http://stackoverflow.com/questions/3606139/php-mysql-and-geolocation computationally expensive Approximate distance in miles sqrt x x y y where x 69.1 lat2 lat1 and y 53.0 lon2 lon1 You can.. math function Improved approximate distance in miles sqrt x x y y where x 69.1 lat2 lat1 and y 69.1 lon2 lon1 cos lat1..
How to efficiently find the closest locations nearby a given location http://stackoverflow.com/questions/3922404/how-to-efficiently-find-the-closest-locations-nearby-a-given-location Number of degrees radian for conversion distance radius pi sqrt point1 'lat' point2 'lat' point1 'lat' point2 'lat' cos point1..
Face detection in PHP http://stackoverflow.com/questions/4159924/face-detection-in-php y w iiw x ii2 y iiw x w inv_area mean mean vnorm vnorm 1 sqrt vnorm 1 passed true for i_stage 0 i_stage count this detection_data..
Geo-Search (Distance) in PHP/MySQL (Performance) http://stackoverflow.com/questions/5236921/geo-search-distance-in-php-mysql-performance 0 sinLambda sin lambda cosLambda cos lambda sinSigma sqrt cosU2 sinLambda cosU2 sinLambda cosU1 sinU2 sinU1 cosU2 cosLambda..
z-Scores(standard deviation and mean) in PHP http://stackoverflow.com/questions/5434648/z-scoresstandard-deviation-and-mean-in-php array square root of sum of squares devided by N 1 return sqrt array_sum array_map sd_square array array_fill 0 count array..
Cosine similarity vs Hamming distance http://stackoverflow.com/questions/945724/cosine-similarity-vs-hamming-distance isset uniqueTokensB token 1 0 a x y b x c y return b c 0 a sqrt b c 0 It is fast isset instead of in_array is a killer on large..
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