Change number of products that are displayed per page

This code sets the number of products displayed on each page of the category view.

		/**
 * Change number of products that are displayed per page
 */

add_filter('loop_shop_per_page', 'cc_new_loop_shop_per_page', 20);

function cc_new_loop_shop_per_page( $cols ) {

  $cols = 20; // insert the number to be shown per page
  return $cols;

}