Here is a simple number digit counter function, I used it to check if a number is a palindrome or not, Plus a Distance function, slope formula, sum from one to an integer, sum of odd numbers from one to specified number, and last but not least the sum of the squares of the values of the sine of x, and the cosine of y.
<?php
function digit_count($num){
for($i=0;pow(10,$i)<=$num;$i++){
if(pow(10,$i+1)>$num){
$num_digits = $i+1;
}
}
return $num_digits;
}
function distance($x_1,$y_1,$x_2,$y_2){
return sqrt(pow($x_1-$x_2,2)+pow($y_1-$y_2,2));
}
function slope($x_1,$y_1,$x_2,$y_2){
return ($y_2-$y_1)/($x_2-$x_1);
}
// example sum(20)=210=1+2+3+...+20
function sum($x){
return ($x)($x+1)/2;
}
// example odd(15)=225=1+3+5+7+9+...+15
function odd($x){
if(($x%2) == 0){
$x-=1;
}
$y=($x+1)/2;
return pow($y,2); //Same as $y*$y;
}
function ($x,$y){
if($x=90-$y){
echo "(Sine of $x)^2 + (Cosine of $y)^2=1";
$value = 1;
}else{
$value = pow(sin($x),2)+pow(cos($y),2);
}
return $value;
}
?>
Математические функции
- Введение
- Установка и настройка
- Предопределенные константы
-
Математические функции
- abs — Модуль числа
- acos — Arc cosine
- acosh — Inverse hyperbolic cosine
- asin — Arc sine
- asinh — Inverse hyperbolic sine
- atan2 — Arc tangent of two variables
- atan — Arc tangent
- atanh — Inverse hyperbolic tangent
- base_convert — Convert a number between arbitrary bases
- bindec — Binary to decimal
- ceil — Округляет дробь в большую сторону
- cos — Cosine
- cosh — Hyperbolic cosine
- decbin — Decimal to binary
- dechex — Decimal to hexadecimal
- decoct — Decimal to octal
- deg2rad — Converts the number in degrees to the radian equivalent
- exp — Calculates the exponent of e
- expm1 — Returns exp(number) - 1, computed in a way that is accurate even when the value of number is close to zero
- floor — Округляет дробь в меньшую сторону
- fmod — Возвращает дробный остаток от деления
- getrandmax — Вовзращает максимально возможное случайное число
- hexdec — Hexadecimal to decimal
- hypot — Calculate the length of the hypotenuse of a right-angle triangle
- is_finite — Finds whether a value is a legal finite number
- is_infinite — Finds whether a value is infinite
- is_nan — Finds whether a value is not a number
- lcg_value — Combined linear congruential generator
- log10 — Base-10 logarithm
- log1p — Returns log(1 + number), computed in a way that is accurate even when the value of number is close to zero
- log — Natural logarithm
- max — Находит наибольшее значение
- min — Находит наименьшее значение
- mt_getrandmax — Show largest possible random value
- mt_rand — Generate a better random value
- mt_srand — Seed the better random number generator
- octdec — Octal to decimal
- pi — Возвращает число Пи
- pow — Exponential expression
- rad2deg — Converts the radian number to the equivalent number in degrees
- rand — Генерирует случайное число
- round — Округляет число типа float
- sin — Sine
- sinh — Hyperbolic sine
- sqrt — Square root
- srand — Изменяет начальное число генератора псевдослучайных чисел
- tan — Tangent
- tanh — Hyperbolic tangent
User Contributed Notes
Math
Math
Anonymous:
23-Dec-2008 07:20
23-Dec-2008 07:20
Sanjay Ichalkaranje
11-Oct-2008 08:34
11-Oct-2008 08:34
This is the only function I searched that I did not find anywhere on the Internet. This function calculates standard normal cumulative distribution for a particular value. This is NORMSDIST(x) in MS-Excel or OpenOffice.org Calc program.
<?
function normalDist($zScore) {
$p = floatval(0.2316419);
$b1 = floatval(0.319381530);
$b2 = floatval(-0.356563782);
$b3 = floatval(1.781477937);
$b4 = floatval(-1.821255978);
$b5 = floatval(1.330274429);
$t = 1/(1 + ($p * floatval($zScore)));
$zx = (1/(sqrt(2 * pi())) * (exp(0 - pow($zScore, 2)/2)));
$px = 1 - floatval($zx) * (($b1 * $t) + ($b2 * pow($t, 2)) + ($b3 * pow($t, 3)) + ($b4 * pow($t, 4)) + ($b5 * pow($t,5)));
return $px;
}
?>