Fungsi Numerik Dasar Dan Mudah di PHP

<?php

$number1=28.12;
$number2=-1.2;
//Ceiling and Floor.
//According to Wikipedia, Floor  is the largest integer not greater than x and Ceiling is the smallest integer not less than x. Source: http://en.wikipedia.org/wiki/Floor_and_ceiling_functions
echo "<p>The ceil of $number1 is ". ceil($number1) ."</p>";
echo "<p>The floor of $number1 is ". floor($number1) ."</p>";

//absolute: |number|
//Explanation from Wikipedia here: http://en.wikipedia.org/wiki/Absolute_value
echo "<p>The absolute of $number1 is ". abs($number1) ."</p>";
echo "<p>The absolute of $number2 is ". abs($number2) ."</p>";

//power of: raise one number to the power of another
//e.g.: 2^3=8
echo "<p>5<sup>3</sup> is ". pow(5,3) ."</p>";

//exponent
//Exponent here is almost the same like the functions pow above. 
//The exp() function returns e raised to the power of x (e^x).
//'e' is the base of the natural system of logarithms (approximately 2.718282) and x is the number passed to it.
echo "<p>The exponent of 10 = ". exp(10) ."</p>";

//logarithm e.g.:log2(8)
echo "<p>log<sub>2</sub>(8) = ". log(8,2) ."</p>";
echo "<p>log<sub>10</sub>(100) = ". log(100,10) ."</p>";

?>