PHP ~ calculating thumbnail dimensions

gistfile1.php

<?php

function calculateThumbnailDimensions( $dim, $max )
{
    $more = max( $dim );
    $more_max = $max[ end( array_keys($dim, $more) ) ];

    $scale = $more_max / $more;

    return ($more_max == $max[0]) ? array($max[0], (int)($dim[1] * $scale)) : array((int)($dim[0] * $scale), $max[1]);
}

function calculateThumbnailDimensions2( $dim, $max )
{
    if( $dim[0] > $dim[1] )
    {
        $ratio = $max[0] / $dim[0];
    }
    else
    {
        $ratio = $max[1] / $dim[1];
    }

    return array( (int)($dim[0] * $ratio), (int)($dim[1] * $ratio) );
}

echo implode('x', calculateThumbnailDimensions2( array(100, 53), array( 155, 155 ) ) ) . PHP_EOL;