Re: Checking existance of global variable in function?

[Etienne Grossmann]

  Btw, this is more a address@hidden mail, iigic.

On Sun, Jul 16, 2006 at 10:16:24AM -0400, Etienne Grossmann wrote:
# 
#   Hi Volker,
# 
# what about testing whether graphdir is a string, as in:
# 
# function [out] = plotinit (eps, file, gnuplotfile)
# global graphdir
# if (exist('graphdir') ~= 0)
#   if ~ischar(graphdir), graphdir = ''; end
#   graphdir=[graphdir '']
# 
# Hth,
# 
#   Etienne
# 
# PS: You are appending an empty string to graphdir?
# 
# On Sun, Jul 16, 2006 at 08:10:21PM +1200, Volker Kuhlmann wrote:
# # I'm trying to check a global variable inside a function file. This
# # construction:
# # 
# # function [out] = plotinit (eps, file, gnuplotfile)
# # global graphdir
# # if (exist('graphdir') ~= 0)
# #     graphdir=[graphdir '']
# # 
# # produces
# # warning: implicit conversion from matrix to string
# # on the first access to graphdir. exist() always returns 1, caused by the
# # global declaration in the function file. Obviously this global
# # declaration can't be removed, but I don't see a way to test inside a
# # function whether a global variable has been set, without causing a
# # warning.
# # 
# # Is this a bug, meant to be impossible, or am I thick?
# # 
# # GNU Octave, version 2.1.72 (x86_64-suse-linux).
# # 
# # Thanks,
# # 
# # Volker
# # 
# # -- 
# # Volker Kuhlmann                     is list0570 with the domain in header
# # http://volker.dnsalias.net/ Please do not CC list postings to me.
# 
# -- 
# Etienne Grossmann ------ http://www.cs.uky.edu/~etienne

-- 
Etienne Grossmann ------ http://www.cs.uky.edu/~etienne