function vis(selection, animate) {
    var width  = 960,
        height = 401;

    var x = d3.scale.ordinal().domain([0, 1])
        .rangeBands([0, width], 0.1);
    var y = d3.scale.ordinal().domain([0, 1, 2, 3, 4, 5])
        .rangeBands([height, 0], 0.2);

    // The initial and final value of animated elements
    var bar_y = {
        'initial' : height,
        'final' : function(d) { return y(d[1]); }
    };

    var canvas = d3.select(selection)
      .append('svg:svg')
      .attr('width', width)
      .attr('height', height);

    var bars = canvas.selectAll('cols')
        .data([[0, 1, 2], [0, 1, 2, 3, 4, 5]])
      .enter().append('svg:g').selectAll('bars')
        .data(function(d, i) { 
            return d.map(function(e) { return [i, e]; });
        })
      .enter().append('svg:rect')
        .attr('class', 'bar')
        .attr('width', x.rangeBand())
        .attr('height', y.rangeBand())
        .attr('x', function(d) { return x(d[0]); })
        .attr('y', bar_y[animate ? 'initial' : 'final'])

    if (animate) {
        bars.transition()
          .duration(1000)
          .attr('y', bar_y['final'])
    }
}