Plot graph with error bars.

  ERRORBAR(X,Y,E) plots the graph of vector X vs. vector Y with

  error bars specified by the vector E.  The vectors X,Y and E must

  be the same length.  If X,Y, and E are matrices then each column

  produces a separate line.  The error bars are each drawn a distance

  of E(i) above and below the points in (X,Y) so that each bar 

  is 2*E(i) long.



  ERRORBAR(Y,E) plots Y with error bars E.



  For example,



     x = 1:10;

     y = sin(x);

     e = std(y)*ones(size(x));




  draws error bars of unit standard deviation.