code: public static PlotCanvas plot(String id, double[] data, double[] breaks) {
          return plot(id, data, breaks, true);
      }
docs: Create a plot canvas with the histogram plot of given data.
  @param id the id of the plot.
  @param data a sample set.
  @param breaks an array of size k+1 giving the breakpoints between
  histogram cells. Must be in ascending order.