Exponential and Logarithmic Functions in PHP
| Function Name | Function Description |
|---|---|
| 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 |
| 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 |
| pow() | Exponential expression |
| sqrt() | Square root |
PHP exp() Function
PHP exp() Usage
The PHP exp()e raised to the power of arg.
PHP exp() Syntax
exp ( float $arg ) : floatPHP exp() Parameters
arg— The argument to process
PHP exp() Return Value
The PHP exp() function returns ‘e’ raised to the power of arg
PHP exp() Working Examples
1. exp() example
<?php
echo exp(12) . "\n";
echo exp(5.7);
?>Output of the above code:
1.6275E+005
298.87Important Points about PHP exp() Function
‘
e‘ is the base of the natural system of logarithms, or approximately 2.718282.
PHP expm1() Function
PHP expm1() Usage
The PHP expm1()
PHP expm1() Syntax
expm1 ( float $arg ) : floatPHP expm1() Parameters
arg— The argument to process
PHP expm1() Return Value
The PHP expm1() function returns ‘e’ to the power of arg minus one
Changelog for PHP expm1() Function
5.3.0 — This function is now available on all platforms
PHP log10() Function
PHP log10() Usage
The PHP log10()arg.
PHP log10() Syntax
log10 ( float $arg ) : floatPHP log10() Parameters
arg— The argument to process
PHP log10() Return Value
The PHP log10() function returns the base-10 logarithm of arg
PHP log1p() Function
PHP log1p() Usage
The PHP log1p()
PHP log1p() Syntax
log1p ( float $number ) : floatPHP log1p() Parameters
number— The argument to process
PHP log1p() Return Value
The PHP log1p() function returns log(1 + number)
Changelog for PHP log1p() Function
5.3.0 — This function is now available on all platforms
PHP log() Function
PHP log() Usage
The PHP log()arg, otherwise log() return the natural logarithm of arg.
PHP log() Syntax
log ( float $arg [, float $base = M_E ] ) : floatPHP log() Parameters
arg— The value to calculate the logarithm forbase— The optional logarithmic base to use (defaults to ‘e’ and so to the natural logarithm).
PHP log() Return Value
The PHP log() function returns the logarithm of arg to base, if given, or the natural logarithm.
PHP pow() Function
PHP pow() Usage
The PHP pow()base raised to the power of exp.
PHP pow() Syntax
pow ( number $base , number $exp ) : numberPHP pow() Parameters
base— The base to useexp— The exponent
PHP pow() Return Value
The PHP pow() function returns d with integer type, otherwise it will be returned as a float.
PHP pow() Working Examples
1. Some examples of pow()
<?php
var_dump(pow(2, 8)); // int(256)
echo pow(-1, 20); // 1
echo pow(0, 0); // 1
echo pow(10, -1); // 0.1
echo pow(-1, 5.5); // PHP >=5.2.2: NAN
echo pow(-1, 5.5); // PHP <5.2.2: -NAN
?>Important Points about PHP pow() Function
In PHP 5.6 onwards, you may prefer to use the ** operator.
This function will convert all input to a number, even non-scalar values, which could lead to weird results.
Additional Tips from Fellow Developers
Contributed By: chris
Many notations use "^" as a power operator, but in PHP (and other C-based languages) that is actually the XOR operator. You need to use this 'pow' function, there is no power operator.
i.e. 3^2 means "3 XOR 2" not "3 squared".
It is particular confusing as when doing Pythagoras theorem in a 'closet points' algorithm using "^" you get results that look vaguely correct but with an error.Contributed By: gilthans
Note that pow(0, 0) equals to 1 although mathematically this is undefined.PHP sqrt() Function
PHP sqrt() Usage
The PHP sqrt()arg.
PHP sqrt() Syntax
sqrt ( float $arg ) : floatPHP sqrt() Parameters
arg— The argument to process
PHP sqrt() Return Value
The PHP sqrt() function returns the square root of arg or the special value NAN for negative numbers.
PHP sqrt() Working Examples
1. sqrt() example
<?php
// Precision depends on your precision directive
echo sqrt(9); // 3
echo sqrt(10); // 3.16227766 ...
?>Rate this post —
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