plplot-devel

[Plplot-devel] tcl binding now works on AT branch

[Alan W. I. <ir...@be...>]

Actually the AT tcl binding was fine last night, but I just didn't know it.

I had a tough time finding what the problem was because somebody stripped
the error messages out of tclAPI.c so it just failed silently when the
extended search failed.  That is not a good situation since the extended
search is still unreliable.  This silent failure may be the reason why
nobody seems to be seriously trying the fundamentally important tclsh (or
wish) methods of running plplot commands.

Turns out the extended search does not work for tclsh if you use any install
locations other than /usr and /usr/local/plplot.  For AT tests, I happened
to be using an install location of /usr/local/plplot_at.  I haven't actually
tested the new code on /usr/local/plplot because I have my comparison tree
there from MAIN HEAD, but setting PL_LIBRARY to
/usr/local/plplot_at/lib/plplot5.1.0/tcl fixed the search problem, and after
that change several tcl examples looked good on AT for the both the pltcl
and tclsh methods.

Alan

email: ir...@be...
phone: 250-727-2902	FAX: 250-721-7715
snail-mail:
Dr. Alan W. Irwin
Department of Physics and Astronomy,
University of Victoria, P.O. Box 3055,
Victoria, British Columbia, Canada, V8W 3P6
__________________________

Linux-powered astrophysics
__________________________

Re: [Plplot-devel] tcl binding now works on AT branch

[Maurice L. <mj...@ga...>]

Alan W. Irwin writes:
 > Actually the AT tcl binding was fine last night, but I just didn't know it.
 > 
 > I had a tough time finding what the problem was because somebody stripped
 > the error messages out of tclAPI.c so it just failed silently when the
 > extended search failed.  That is not a good situation since the extended
 > search is still unreliable.  This silent failure may be the reason why
 > nobody seems to be seriously trying the fundamentally important tclsh (or
 > wish) methods of running plplot commands.

If the extended search fails PlbasicInit() returns TCL_ERROR, which: (a) is
all the info you really need since you have a stack trace to find where the
error occured, and (b) there's no other info to give really -- at the point
of failure "libdir" is NULL after several tries to give it a value.  I suppose
one nice enhancement would be for PlbasicInit() to set its internal debug
variable using a Tcl global variable of the same name so you could get
immediate feedback w/o recompilation.

But anyway for now to get more info on the search process recompile with
debug=1 in PlbasicInit() and see what it tells you, that should help.

-- 
Maurice LeBrun    mj...@ga...
Research Organization for Information Science and Technology of Japan (RIST)

Re: [Plplot-devel] tcl binding now works on AT branch

[Alan W. I. <ir...@be...>]

On Sat, 30 Nov 2002, Maurice LeBrun wrote:

> If the extended search fails PlbasicInit() returns TCL_ERROR, which: (a) is
> all the info you really need since you have a stack trace to find where the
> error occured

I have seen the stack trace put out by plframe for other errors, and that
was most useful, but in the tcl-only situation with no tk driver or plframe
is there another way to get at it?  I was floundering around yesterday
because I didn't know how to get a stack trace for the tcl-only situation.

Anyhow, I am now using the PL_LIBRARY workaround, but the code has access to
DATA_DIR and therefore the exact install location (DATA_DIR "../tcl) for
plplot.tcl so eventually (post-merge) I believe we should put that install
location in the code as a possibility for the unix extended search.

Alan

Re: [Plplot-devel] tcl binding now works on AT branch

[Maurice L. <mj...@ga...>]

Alan W. Irwin writes:
 > On Sat, 30 Nov 2002, Maurice LeBrun wrote:
 > 
 > > If the extended search fails PlbasicInit() returns TCL_ERROR, which: (a) is
 > > all the info you really need since you have a stack trace to find where the
 > > error occured
 > 
 > I have seen the stack trace put out by plframe for other errors, and that
 > was most useful, but in the tcl-only situation with no tk driver or plframe
 > is there another way to get at it?  I was floundering around yesterday
 > because I didn't know how to get a stack trace for the tcl-only situation.

Sorry I never got back to you on this one.  Sheesh, have I ever been busy
since you posed it three weeks ago.  Anyway, the simple answer is: "puts
$errorInfo".  See "man n error" for more info.

We could probably improve the Tcl error handling (not to mention many other
areas of Tcl support) in plplot.  I didn't get to do as much with this over
the last year as I wanted but am still hoping..

-- 
Maurice LeBrun    mj...@ga...
Research Organization for Information Science and Technology of Japan (RIST)