Given two vectors of x-y data, bar produces a bar graph.

If only one argument is given, it is taken as a vector of y-values and the x coordinates are taken to be the indices of the elements.

If two output arguments are specified, the data are generated but not plotted. For example,

          bar (x, y);

and

          [xb, yb] = bar (x, y);
          plot (xb, yb);

are equivalent.