2.8 Modified errorbar which Cycles Through Line Styles

Problem

If X and Y are MxN arrays, errorbar generates a plot using the same line style. On a monochrome monitor, it's hard to distinguish between the lines. Is it possible to force errorbar to cycle through the line styles?

Solution

The reason that errorbar generates the plots using solid lines is because errorbar defaults to a solid line when fewer than five inputs are used. Below is a modified version of errorbar which cycles through the lines defined in the axes LineStyleOrder property on monochrome monitors.

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function errorbar(x, y, l,u,symbol)
%ERRORBAR Plot graph with error bars.
%  ERRORBAR(X,Y,L,U,SYMBOL) plots the graph of vector X 
%  vs. vector Y with error bars specified by the vectors 
%  L and U.  The vectors X,Y,L and U must be the same 
%  length.  If X,Y, L and U are matrices then each column
%  produces a separate line.  The error bars are each drawn
%  a distance of U(i) above and L(i) below the points in
%  (X,Y) so that each bar is L(i) + U(i) long. SYMBOL is 
%  a string that controls the line type, plotting symbols
%  and color for the X-Y plot.  
%
%  ERRORBAR(X,Y,L) plots X versus Y with an error bar that
%  is symmetric about Y and is 2*L(i) long.
%
%  ERRORBAR(Y,L) plots Y with error bars [Y-L Y+L].
%
%  For example,
%
%   x = 1:10;
%   y = sin(x);
%   e = std(y)*ones(size(x));
%   errorbar(x,y,e)
%
%  draws symmetric error bars of unit standard deviation.
%  L. Shure 5-17-88, 10-1-91 B.A. Jones 4-5-93
%  Copyright (c) 1984-93 by The MathWorks, Inc.
if min(size(x))==1,
  npt = length(x);
  x = x(:);
  y = y(:);
  if nargin == 3,  
    l = l(:);
  elseif nargin == 4 | nargin == 5
    l = l(:);
    u = u(:);
  end
else
  [npt,n] = size(x);
end
if nargin == 3,  
  u = l;
end
if nargin == 2
  l = y;
  u = y;
  y = x;
  [m,n] = size(y);
  x(:) = [1:npt]'*ones(1,n);;
end
if isstr(x) | isstr(y) | isstr(l) | isstr(u)
  error('Arguments must be numeric.')
end
if any(size(x)~=size(y)) | any(size(x)~=size(l)) |
any(size(x)~=size(u)),
  error('The sizes of X, Y, L and U must be the same.');
end
tee = (max(x(:))-min(x(:)))/100;  % make tee .02 
                                  % x-distance for 
                                  % error bars
xl = x - tee;
xr = x + tee;
n = size(y,2);
% Plot graph and bars
cax = newplot;
next = lower(get(cax,'NextPlot'));
% build up nan-separated vector for bars
xb = [];
yb = [];
nnan = nan*ones(1,n);
for i = 1:npt
  ytop = y(i,:) + u(i,:);
  ybot = y(i,:) - l(i,:);
  xb = [xb; x(i,:); x(i,:) ; nnan;  
        xl(i,:);xr(i,:);nnan;xl(i,:);xr(i,:);nnan];
  yb = [yb; ytop;ybot;nnan;ytop;ytop;nnan;ybot;ybot;nnan];
end
% MODIFIED 04/01/94 BY JOHN L. GALENSKI III
% IF X AND Y ARE MxN ARRAYS, MATLAB WILL CYCLE
% THROUGHT COLORS ON A COLOR MONITOR IF 'SYMBOL'
% IS NOT GIVEN.  ON A MONOCHROME MONITOR, MATLAB
% WILL CYCLE THROUGH THE LINE STYLES DEFINED IN
% THE AXES 'LineStyleOrder' PROPERTY.
if nargin ~= 5 & min(size(x)) == 1 & min(size(y)) == 1
  symbol = '-';
  plot(xb,yb,x,y,symbol)
else
  plot(xb,yb,x,y)
end