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Mathematical Functions

簡介

These math functions will only handle values within the range of the integer and float types on your computer (this corresponds currently to the C types long resp. double). If you need to handle bigger numbers, take a look at the arbitrary precision math functions.

See also the manual page on arithmetic operators.

需求

要編譯本擴充功能無需外部函式庫。

安裝

本擴充功能作為 PHP 核心的一部分,無需安裝即可使用。

執行時期設定

本擴充功能在 php.ini 中未定義任何設定選項。

資源類型

本擴充功能未定義任何資源類型。

預設常數

以下常數作為 PHP 核心的一部分且一直有效。

Math constants
Constant Value Description
M_PI 3.14159265358979323846 Pi
M_E 2.7182818284590452354 e
M_LOG2E 1.4426950408889634074 log_2 e
M_LOG10E 0.43429448190325182765 log_10 e
M_LN2 0.69314718055994530942 log_e 2
M_LN10 2.30258509299404568402 log_e 10
M_PI_2 1.57079632679489661923 pi/2
M_PI_4 0.78539816339744830962 pi/4
M_1_PI 0.31830988618379067154 1/pi
M_2_PI 0.63661977236758134308 2/pi
M_SQRTPI 1.77245385090551602729 sqrt(pi) [5.2.0]
M_2_SQRTPI 1.12837916709551257390 2/sqrt(pi)
M_SQRT2 1.41421356237309504880 sqrt(2)
M_SQRT3 1.73205080756887729352 sqrt(3) [5.2.0]
M_SQRT1_2 0.70710678118654752440 1/sqrt(2)
M_LNPI 1.14472988584940017414 log_e(pi) [5.2.0]
M_EULER 0.57721566490153286061 Euler constant [5.2.0]
Only M_PI is available in PHP versions up to and including PHP 4.0.0. All other constants are available starting with PHP 4.0.0. Constants labeled [5.2.0] were added in PHP 5.2.0.

Table of Contents

  • abs — Absolute value
  • 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 — Round fractions up
  • 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 — Round fractions down
  • fmod — Returns the floating point remainder (modulo) of the division of the arguments
  • getrandmax — Show largest possible random value
  • 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 — Find highest value
  • min — Find lowest value
  • 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 — Get value of pi
  • pow — Exponential expression
  • rad2deg — Converts the radian number to the equivalent number in degrees
  • rand — Generate a random integer
  • round — Rounds a float
  • sin — Sine
  • sinh — Hyperbolic sine
  • sqrt — Square root
  • srand — Seed the random number generator
  • tan — Tangent
  • tanh — Hyperbolic tangent