On 11/1/07, Ursula Whitcher <[EMAIL PROTECTED]> wrote:
>
> (I tried to post about my problem once before, so my apologies if this
> comes through twice.)
>
> I'm receiving a segmentation error when I try to run a procedure in
> the Singular console in Sage. I've previously tested this procedure
> in Singular (run by itself) and it worked as designed, so I think that
> something may be going wrong in the Sage interface.
>
> Here's my procedure:
>
> proc reducePoleOrder (poly pPoly, ideal Jacob, ideal xVariables) {
> list divL = division(pPoly, Jacob);
> print("division complete");
> matrix divM = divL[1];
> ideal divI = ideal(divM);
> matrix redM = diff(xVariables, divI);
> print("reduction complete");
> poly redPoly = trace(redM);
> print("trace complete");
> return(redPoly);
> }
>
> If I type:
>
> ring R = (0,t), (a,b,c), dp;
> poly Q = 1/3*(a^3+b^3+c^3)-t*a*b*c;
> ideal QIdeal = Q;
> ideal abcVars = a,b,c;
> ideal Jac = diff(abcVars, QIdeal);
> ideal JacG = groebner(Jac);
> short = 0;
>
> and then try
>
> reducePoleOrder(a^2*b^2*c^2, Jac, abcVars);
>
> the correct result is displayed:
>
> (-2*t^2)/(t^3-1)*a*b*c+(-t)/(t^3-1)*c^3
>
> However, the command
>
> poly testPoly = reducePoleOrder(a^2*b^2*c^2, Jac, abcVars);
> testPoly;
>
> returns the error message:
>
> Singular : signal 11 (v: 3032/2007102509):
> Segment fault/Bus error occurred at 3f because of 10202 (r:1193943964)
> please inform the authors
> trying to restart...
I cannot reproduce this using an intel mac:
david-joyners-computer:~/sagefiles/sage-2.8.2 wdj$ ./sage
----------------------------------------------------------------------
| SAGE Version 2.8.8.1, Release Date: 2007-10-21 |
| Type notebook() for the GUI, and license() for information. |
----------------------------------------------------------------------
sage: singular_console()
SINGULAR / Development
A Computer Algebra System for Polynomial Computations / version 3-0-3
0<
by: G.-M. Greuel, G. Pfister, H. Schoenemann \ May 2007
FB Mathematik der Universitaet, D-67653 Kaiserslautern \
> proc reducePoleOrder (poly pPoly, ideal Jacob, ideal xVariables) {
. list divL = division(pPoly, Jacob);
. print("division complete");
. matrix divM = divL[1];
. ideal divI = ideal(divM);
. matrix redM = diff(xVariables, divI);
. print("reduction complete");
. poly redPoly = trace(redM);
. print("trace complete");
. return(redPoly);
. }
>
. ;
> ring R = (0,t), (a,b,c), dp;
> poly Q = 1/3*(a^3+b^3+c^3)-t*a*b*c;
> ideal QIdeal = Q;
> ideal abcVars = a,b,c;
> ideal Jac = diff(abcVars, QIdeal);
> ideal JacG = groebner(Jac);
> short = 0;
> poly testPoly = reducePoleOrder(a^2*b^2*c^2, Jac, abcVars);
division complete
reduction complete
trace complete
> testPoly;
(-2*t^2)/(t^3-1)*a*b*c+(-t)/(t^3-1)*c^3
> reducePoleOrder(a^2*b^2*c^2, Jac, abcVars);
division complete
reduction complete
trace complete
(-2*t^2)/(t^3-1)*a*b*c+(-t)/(t^3-1)*c^3
> poly testPoly = reducePoleOrder(a^2*b^2*c^2, Jac, abcVars);
// ** redefining testPoly **
division complete
reduction complete
trace complete
> testPoly;
(-2*t^2)/(t^3-1)*a*b*c+(-t)/(t^3-1)*c^3
>
> I used the Singular monitor("testfile.txt","io"); command to record
> the input & output for this series of commands, and it has:
>
> ***
>
> poly testPoly = reducePoleOrder(a^2*b^2*c^2, Jac, abcVars);
> (null)
> print("division complete");
> matrix divM = divL[1];
> ideal divI = ideal(divM);
> matrix redM = diff(xVariables, divI);
> print("reduction complete");
> poly redPoly = trace(redM);
> print("trace complete");
> return(redPoly);
>
>
> ;return();
>
>
> (null)
> print("reduction complete");
> poly redPoly = trace(redM);
> print("trace complete");
> return(redPoly);
>
>
> ;return();
>
>
> (null)
> print("trace complete");
> return(redPoly);
>
>
> ;return();
>
> ***
>
> It looks to me like extra null values and an empty return statement
> are being inserted in my procedure, so that a meaningless value is
> assigned to testPoly and the program crashes when I try to analyze
> testPoly.
>
> UAW
>
>
> >
>
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