Gottfried Barthel on Fri, 22 Nov 2002 19:01:48 +0100 (MET)


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Problem with Pari for the Mac : Help with "polrootspadic" needed


Hello Pari experts, 

could someone of you provide me with a script for "polrootspadic" ? 

The question might surprise you since "polrootspadic" is a built-in
function, so here is the reason why I am asking: When trying to run a
certain Pari/GP script on my Mac (a PowerBook with the "old" Mac OS 8.6),
I was stopped by the following strange error message:

  "***   root does not exist in rootpadic". 

Fortunately, the script that I was trying to run is short and nicely
documented, so I could spot the point where the error occurs, and isolate
the problem: It occurs, e.g., when running the command:

=== begin Pari/GP ===
? n=29; k=3; d=3; polrootspadic(x^k-n,2,d+1)
  ***   root does not exist in rootpadic
=== end Pari/GP ===

The problem does not occur when running the command in Pari/GP 2.1.4 on a
SUN. 

Upon the help command "? rootpadic", Pari tells me: 

=== begin Pari/GP ===
? ? rootpadic
  ***   obsolete function: rootpadic
                           ^--------
For full compatibility with GP 1.39, type "default(compatible,3)"
(you can also set "compatible = 3" in your GPRC file)

New syntax: rootpadic(x,p,r) ===> polrootspadic(x,p,r)

polrootspadic(x,p,r): p-adic roots of the polynomial x to precision r.
=== end Pari/GP ===

The point is that in the script as in the example above, the command 
actually _is_  polrootspadic(poly, p, r) . Now "\d" says 
   compatible = 0 (no backward compatibility)
so obsolete commands from Pari 1.39 should not be executed. 

The version of Pari that I am using identifies itself as follows:

                                  2.0.12 alpha
                                PowerPC version
                (readline disabled, extended help not available)

This seems to be the only version (executable dated Febr. 10, 1998 in 
the Mac's "Show info") that is available for the "classical" Mac OS (i.e.,
before the switch to the BSD-based OS X), though it is referrred to as
"gp-2.0.14.sit.bin (2.0.14)" in the "Download/ Precompiled executables: /
...for Macintosh" section on the web page 
http://www.gn-50uma.de/ftp/pari/00index.html

I know that more recent versions are available for Mac OS X, but I am 
afraid that OS X would not run with reasonable speed on my Mac (PowerBook
G3 "Wallstreet"). So in spite of several -- actually rather annoying --
shortcomings of the Mac implementation (not diminishing Dominique 
Bernardi's merits with the port, since without his efforts, there would be
no Mac implementation at all!), I have to stick with this version!

Thanks in advance for your help! Best regards,

Gottfried Barthel 

Fachbereich Mathematik und Statistik, Universitaet Konstanz