code: function() {
      this.bar_padding = this.options.bar_padding || 5;
      this.bar_width = this.options.bar_size || this.calculateBarWidth();
  
      if (this.options.bar_size && !this.options.bar_padding) {
        this.bar_padding = this.graph_width / this.data_size;
      }
  
      this.options.plot_padding = (this.bar_width / 2) - (this.bar_padding / 2);
      this.step = this.calculateStep();
      this.grid_start_offset = this.bar_padding - 1;
      this.start_y = this.options.height - this.y_padding_bottom;
    }
docs: Options specific to BarGraph.