ErrorBarFunction question.
- To: mathgroup at smc.vnet.net
- Subject: [mg12709] ErrorBarFunction question.
- From: Rob Smith <rob at groucho.med.jhmi.edu>
- Date: Wed, 3 Jun 1998 02:21:00 -0400
- Sender: owner-wri-mathgroup at wolfram.com
MathUsers:
I am having trouble defining my own function for error bars in
MultipleListPlot that I think is probably a pattern matching problem.
Basically, I just want error bars without the horizontal lines (serifs)
at each end of the bar. Without using ErrorBarFunction the plot comes
out as expected. I have unsymmetrical error and, thus, have a list of
the following form:
{{0.28, 0.13}, ErrorBar[{-0.19, 0.32}]} ...
^ ^ ^ ^
x y negerr poserr
So the corresponding error bar can be represented by a line from
(x,y+negerr) to (x, y+poserr); note that negerr is negative, hence
y+negerr. So I defined an error bar function as follows:
barfunc[{x_, y_}, ErrorBar[{negerr_, poserr_}] :=
Line[{{x, y+negerr}, {x, y+poserr}}]
And then included in the MultipleListPlot statement:
ErrorBarFunction -> barfunc
Obviously this doesn't work or you wouldn't be reading this! I've
played the usual brace games and still can't get this to work. The
error I get is:
Unknown Graphics primitive barfunc[{0.28,0.13}, <<1>>] encountered.
Does anybody know what I am doing wrong? Any help would be greatly
appreciated.
Thanks,
Rob Smith
Department of Biophysics & Biophysical Chemistry Johns Hopkins
University School of Medicine 725 N. Wolfe St.
Baltimore, MD 21205-2185