Calculate width based on max height

php

	function rbk_calculate_image_width_based_on_max_height( $filename, $max_height ) {
			if( !empty($filename) ){

				$attributes = getimagesize( $filename );
				$image_width = $attributes[0];
				$image_height = $attributes[1];	

				if( $image_width > $image_height ){
					return $image_width / $image_height * $max_height; 
				} else {
					return $image_height / $image_width * $max_height; 
				}
			}
	}
	$width = rbk_calculate_image_width_based_on_max_height( $logo, 46 );