Hi!
Consider this:
> collect((1-t^2)/(1+t),t);
(t+1)^(-1)
This is clearly wrong...
Bye,
Christian
--
/ Coding on PowerPC and proud of it
\/ http://www.uni-mainz.de/~bauec002/
Hello all,
Apologies if you got this mail twice, but the set of people on ginac-list
and ginac-devel is neither disjoint nor is one a subset of the other...
This is to notify you that we've uploaded version 0.4.1 of GiNaC
yesterday. The updated documentation is sitting on <http://www.ginac.de/>
as well. Please read the News if you are curious on what has changed (it
ain't anything dramatic). Check it out, test it, submit bug-reports and
(if possible) fixes!
Just to keep people informed about current development, let me mention
that the next release will probably feature an interface to the CINT C++
interpreter <http://root.cern.ch/root/Cint.html> by Masaharu Goto. This
will allow people to write C++ scripts interactively and to compile them
later. We'll get another interactive interface to GiNaC besides ginsh
this way---one with all loop constructs, conditionals and containers known
from C++. Currently there are still some weirdnesses concerning automatic
promotion of types which are hopefully fixed soon but we are already quite
excited about the new possibilities.
happy hacking
-rbk.
--
Richard Kreckel
<Richard.Kreckel(a)Uni-Mainz.DE>
<http://wwwthep.physik.uni-mainz.de/~kreckel/>
Aha, I just found this line in the FTP logs:
Mon Nov 29 22:38:38 1999 11 ns.maplesoft.on.ca 337437 /pub/GiNaC/GiNaC-0.4.0.tar.bz2 b _ o a mozilla@ ftp 0 *
Cheers
-richy.
--
Richard B. Kreckel
<Richard.Kreckel(a)Uni-Mainz.DE>
<http://wwwthep.physik.uni-mainz.de/~kreckel/>
Hi!
Just to let you know: I'm away in the time 9.Dec-16.Dec.
Bye,
Christian
--
/ Coding on PowerPC and proud of it
\/ http://www.uni-mainz.de/~bauec002/
As everybody knows we don't have inert differentiation like Maple has for
instance (lprint(diff(f(x),x)); returns diff(f(x),x) there), we are always
applying the full chain rule, end of story. :-/ If a function does not
know how to be differentiated it may throw an exception instead, this is
acceptable. However, when trying to implement differentiation for the
polygamma functions psi(n,x) I ran into a problem with that policy since
differentiating wrt the first argument doesn't make much sense there (it's
normally just an integer parameter). But when one differentiates wrt x,
what happens is this (function::pdiff is the partial differentiation):
psi(n,x).diff(x) -> pdiff(psi,0)*n.diff(x) + pdiff(psi,1)*x.diff(x)
so differentiation wrt n comes in again through the back door. I have
worked around this problem by changing function::diff(). In the above
case it would see that n.diff(x).is_zero() and then refrain from trying
to compute pdiff(psi,0). It seems to work so far. In ginsh, this allows
me to write:
> diff(psi(1,x),x);
psi(2,x)
> diff(psi(n,x),x);
psi(n+1,x)
> diff(psi(n,x),n);
cannot diff psi(n,x) with respect to n
Any objections? (It's in CVS, for those of you who have access to it.)
So, once more we can live without inert differentiation, let's see how
long...
On another note: who has implemented atan2::diff() and why didn't it
return something slightly simpler (i.e. x/(x^2+y^2) instead of
1/x/(1+y^2/x^2))? Is there some reason for this?? Did I break
anything???
Cheers
-rbk.
--
Richard Kreckel
<Richard.Kreckel(a)Uni-Mainz.DE>
<http://wwwthep.physik.uni-mainz.de/~kreckel/>
Hi!
Here is an article that explains some of the issues involved in binary
compatibility for C++ libraries:
http://www-classic.be.com/aboutbe/benewsletter/Issue79.html#Insight
I don't propose that we adopt their solution to the problem because as
GiNaC is an open source project, it's easier for users to upgrade to a
current GiNaC version. But it's nice to know which chanegs to GiNaC will
break binary compatibility (and will require resetting the INTERFACE_AGE
and BINARY_AGE variables in configure.in).
Bye,
Christian
--
/ Coding on PowerPC and proud of it
\/ http://www.uni-mainz.de/~bauec002/
Hi!
After changing 'configure.in', 'acconfig.h' or 'acinclude.m4' you should
run
$ aclocal; autoheader; autoconf; automake
I suggest that you do this on squark because it has newer versions of
autoconf and automake.
After changing one of the 'Makefile.am' files you should run
$ automake; ./config.status
at the top level (i.e. the directory where 'configure.in' lies).
'automake' will generate the 'Makefile.in's and 'config.status' will
recreate the Makefiles according to your last configuration (this
assumes that you didn't change 'configure.in' or did a 'make distclean'
in which case you must re-run 'configure').
These should be the only configuration-related files which you can edit.
Bye,
Christian
--
/ Coding on PowerPC and proud of it
\/ http://www.uni-mainz.de/~bauec002/
Hi!
GiNaC and libxloops are now put into their own namespaces ("GiNaC" and
"xloops", respectively). If you're using GiNaC/libxloops in your own
programs, it should be enough to add
using namespace GiNaC;
using namespace xloops;
after the #include <ginac/ginac.h> or #include <lib/xloops.h> to make
things compile again.
Bye,
Christian
--
/ Coding on PowerPC and proud of it
\/ http://www.uni-mainz.de/~bauec002/
I think we just stop giving away GiNaC for free and sell it like
others do with their symbolic software (vaporware?)...
--
Alexander Frink E-Mail: Alexander.Frink(a)Uni-Mainz.DE
Institut fuer Physik Phone: +49-6131-393391
Johannes-Gutenberg-Universitaet
D-55099 Mainz, Germany
---------- Forwarded message ----------
Date: Fri, 19 Nov 1999 10:15:07 +0200
From: "Nazir S. Baaklini" <nsbaaklini(a)intracom.net.lb>
To: Alexander.Frink(a)Uni-Mainz.DE
Subject: Your opinion
Dear Alexander Frink,
I would appreciate your opinion regarding whether academic
and research scholars such as professors and students shouldn't
be interested in an advanced symbolic computational package for
theoretical physics at the level described and demonstrated on my
web sites addressed below.
In particular, I would like to benefit from your suggestion regarding
the pricing of such a package, especially that I am about to
announce several new applications of this package for the new year...
Gratefully yours,
Professor Nazir S. Baaklini
http://www.nsbaaklini.homepage.com/pacs.htmlhttp://webs.intracom.net.lb/nsbaaklini/pacs.html