Requirements
No external libraries are needed to build this extension.
Installation
There is no installation needed to use these
functions; they are part of the PHP core.
Runtime Configuration
This extension has no configuration directives defined in php.ini.
Resource Types
This extension has no resource types defined.
Predefined Constants
The constants below are always available as part of the PHP core.
Table 1. 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) [4.0.2] |
M_2_SQRTPI | 1.12837916709551257390 | 2/sqrt(pi) |
M_SQRT2 | 1.41421356237309504880 | sqrt(2) |
M_SQRT3 | 1.73205080756887729352 | sqrt(3) [4.0.2] |
M_SQRT1_2 | 0.70710678118654752440 | 1/sqrt(2) |
M_LNPI | 1.14472988584940017414 | log_e(pi) [4.0.2] |
M_EULER | 0.57721566490153286061 | Euler constant [4.0.2] |
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 [4.0.2] were added in PHP 4.0.2.