code: public static PlotCanvas plot(String id, double[]... data) {
          if (data[0].length != 2) {
              throw new IllegalArgumentException("Dataset is not 2-dimensional.");
          }
  
          double[] lowerBound = Math.colMin(data);
          double[] upperBound = Math.colMax(data);
          PlotCanvas canvas = new PlotCanvas(lowerBound, upperBound);
          canvas.getAxis(0).setGridVisible(false);
          BarPlot plot = new BarPlot(data);
          plot.setID(id);
          canvas.add(plot);
  
          return canvas;
      }
docs: Create a plot canvas with the bar plot of given data.
  @param id the id of the plot.
  @param data a n x 2 matrix of which data[][0] determine the location of
  bars and data[][1] determine the heights of bars. data[][0] will also be
  used as the labels. For best view, data[][0] should be monotonic.