WordPress different file extensions

For whatever reason I had a difficult time find this solution. It seemed like most of the articles were out of date. Please let me know if you need any help. Just add this to your functions.php in your theme directory.

Upload .eps

add_filter('upload_mimes', 'custom_upload_mimes');
function custom_upload_mimes ( $existing_mimes=array() ) {
$existing_mimes['eps'] = 'application/postscript, application/eps, application/x-eps, image/eps, image/x-eps';
return $existing_mimes;

I found this solution from Plugin API/Filter Reference/upload mimes & Wolfram .eps