template/html/jquery-tablesorter.js
function( table ) {
         table = $( table )[ 0 ];
         var overallWidth, percent, $tbodies, len, index,
          c = table.config,
          $colgroup = c.$table.children( 'colgroup' );
         // remove plugin-added colgroup, in case we need to refresh the widths
         if ( $colgroup.length && $colgroup.hasClass( ts.css.colgroup ) ) {
            $colgroup.remove();
         }
         if ( c.widthFixed && c.$table.children( 'colgroup' ).length === 0 ) {
            $colgroup = $( '<colgroup class="' + ts.css.colgroup + '">' );
            overallWidth = c.$table.width();
            // only add col for visible columns - fixes #371
            $tbodies = c.$tbodies.find( 'tr:first' ).children( ':visible' );
            len = $tbodies.length;
            for ( index = 0; index < len; index++ ) {
               percent = parseInt( ( $tbodies.eq( index ).width() / overallWidth ) * 1000, 10 ) / 10 + '%';
               $colgroup.append( $( '<col>' ).css( 'width', percent ) );
            }
            c.$table.prepend( $colgroup );
         }
      }
function( table ) {
         table = $( table )[ 0 ];
         var overallWidth, percent, $tbodies, len, index,
          c = table.config,
          $colgroup = c.$table.children( 'colgroup' );
         // remove plugin-added colgroup, in case we need to refresh the widths
         if ( $colgroup.length && $colgroup.hasClass( ts.css.colgroup ) ) {
            $colgroup.remove();
         }
         if ( c.widthFixed && c.$table.children( 'colgroup' ).length === 0 ) {
            $colgroup = $( '<colgroup class="' + ts.css.colgroup + '">' );
            overallWidth = c.$table.width();
            // only add col for visible columns - fixes #371
            $tbodies = c.$tbodies.find( 'tr:first' ).children( ':visible' );
            len = $tbodies.length;
            for ( index = 0; index < len; index++ ) {
               percent = parseInt( ( $tbodies.eq( index ).width() / overallWidth ) * 1000, 10 ) / 10 + '%';
               $colgroup.append( $( '<col>' ).css( 'width', percent ) );
            }
            c.$table.prepend( $colgroup );
         }
      }
automatically add a colgroup with col elements set to a percentage width