Returns a hue value between green and red for an int between 0–100

heatmap-hue.php

<?php

/**
 * heatmap
 *
 * Returns a hue value for HSL colors when given a level between 0–100
 * Will accept higher/lower values, but will be outside of heatmap range
 * Converts a percentage to a number between 0—120 in reverse
 *
 * @param int $level Integer between 0–100
 * @return inst Integer between 0—120
 */

function heatmap($level) { return 120 - ( ( 120 / 100 ) * $level ); }