create various repeating patterns of TRUE / FALSE in a loop

gistfile1.aw

<?php

// patterns

$patterns = array( );

for ($i = 0; $i < 20; ++$i) {

	// the generic alternating patterns

	// 1, 0, 1, 0, ...
	$patterns[0][] = (0 === ($i % 2));

	// 0, 1, 0, 1, ...
	$patterns[1][] = (0 !== ($i % 2));


	// by increasing the value we modulo by, and dividing
	// by half that amount, we can double up the pattern
	// NOTE: the (int) _is_ important here

	// 1, 1, 0, 0, 1, 1, 0, 0, ...
	$patterns[2][] = (0 === (int) floor(($i % 4) / 2));

	// 0, 0, 1, 1, 0, 0, 1, 1, ...
	$patterns[3][] = (0 !== (int) floor(($i % 4) / 2));


	// this process can be continued to higher values

	// 1, 1, 1, 0, 0, 0, 1, 1, 1, 0, 0, 0, ...
	$patterns[4][] = (0 === (int) floor(($i % 6) / 3));

	// 0, 0, 0, 1, 1, 1, 0, 0, 0, 1, 1, 1, ...
	$patterns[5][] = (0 !== (int) floor(($i % 6) / 3));


	// the values do not have to be 2:1 related, or even

	// 1, 1, 0, 0, 0, 1, 1, 0, 0, 0, ...
	$patterns[6][] = (0 === (int) floor(($i % 5) / 2));


	// by adding a value to $i before the modulus, the
	// pattern can be shifted forward or backward

	// 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, ...
	$patterns[7][] = (0 === (int) floor((($i + 1) % 5) / 2));

	/*
	all these patterns can be generalized to:

	( 0 === (int) floor( ( ( $i + $shift ) % $length_of_pattern ) / $num_leading_values ) )

	where $length_of_pattern is the total length of the pattern before repeating (wavelength)
	and $num_leading_values is the number of TRUE values at the start of
	the pattern before it switches to FALSE.
	$shift shifts the pattern by the given amount (+ = forward; - = backward)

	$num_leading_values must be less than $length_of_pattern
	$shift can be any integer, positive or negative, but the pattern will repeat
	so -$length_of_pattern < $shift < $length_of_pattern

	the whole pattern can be reversed by setting === to !==
	leading TRUE becomes FALSE, and vice versa
	*/

}

g($patterns);


if ( ! function_exists('g')) {
	function g($var = null) {
		var_dump($var);
	}
}