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Mathematical Functions

介紹

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

建立這個延伸不需要任何外部程式庫。

安裝

這些函數是PHP核心的一部分,不需要安裝就可使用。

執行時期組態

php.ini中沒有定義此延伸的組態指令。

資源類型

這個延伸沒有定義任何資源。

預先定義常數

以下經常有效常數為PHP核心的一部分。

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