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XL. Mathematical Functions

Introduction

These math functions will only handle values within the range of the long and double types on your computer. If you need to handle bigger numbers, take a look at the arbitrary precision math functions.

Math constants

The following values are defined as constants in PHP by the math extension:

Table 1. Math constants

ConstantValueDescription
M_PI3.14159265358979323846Pi
M_E2.7182818284590452354e
M_LOG2E1.4426950408889634074log_2 e
M_LOG10E0.43429448190325182765log_10 e
M_LN20.69314718055994530942log_e 2
M_LN102.30258509299404568402log_e 10
M_PI_21.57079632679489661923pi/2
M_PI_40.78539816339744830962pi/4
M_1_PI0.318309886183790671541/pi
M_2_PI0.636619772367581343082/pi
M_SQRTPI1.77245385090551602729sqrt(pi) [4.0.2]
M_2_SQRTPI1.128379167095512573902/sqrt(pi)
M_SQRT21.41421356237309504880sqrt(2)
M_SQRT31.73205080756887729352sqrt(3) [4.0.2]
M_SQRT1_20.707106781186547524401/sqrt(2)
M_LNPI1.14472988584940017414log_e(pi) [4.0.2]
M_EULER0.57721566490153286061Euler constant [4.0.2]
Only M_PI is available in PHP versions up to and including PHP4RC1. All other constants are available starting with PHP 4.0. Constants labelled [4.0.2] were added in PHP 4.0.2.

Table of Contents
abs — Absolute value
acos — Arc cosine
asin — Arc sine
atan — Arc tangent
atan2 — arc tangent of two variables
base_convert — Convert a number between arbitrary bases
bindec — Binary to decimal
ceil — Round fractions up
cos — Cosine
decbin — Decimal to binary
dechex — Decimal to hexadecimal
decoct — Decimal to octal
deg2rad — Converts the number in degrees to the radian equivalent
exp — e to the power of ...
floor — Round fractions down
getrandmax — Show largest possible random value
hexdec — Hexadecimal to decimal
lcg_value — Combined linear congruential generator
log — Natural logarithm
log10 — Base-10 logarithm
max — Find highest value
min — Find lowest value
mt_rand — Generate a better random value
mt_srand — Seed the better random number generator
mt_getrandmax — Show largest possible random value
number_format — Format a number with grouped thousands
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 value
round — Rounds a float
sin — Sine
sqrt — Square root
srand — Seed the random number generator
tan — Tangent
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