Re: [Maxima-discuss] ratsimp not working as expected

[Thomas D. D. <to...@wa...>]

On 03/08/14 00:51, andre maute wrote:

 > No, it is not. The first ratsimp line has to be commented.
 > But for GCL this code will even segfault for the invert() in (%i5).

(%i1) showtime:true;
Evaluation took 0.0000 seconds (0.0000 elapsed)
(%o1) true
(%i2) display2d : false;
Evaluation took 0.0000 seconds (0.0000 elapsed)
(%o2) false
(%i3) d : 4$
Evaluation took 0.0000 seconds (0.0000 elapsed)
(%i4) A : genmatrix(lambda([k,l],v[[k,l]]-v[[0,l]]),d,d)$
Evaluation took 0.0000 seconds (0.0000 elapsed)
(%i5) detA : factor(determinant(A))$
Evaluation took 0.0100 seconds (0.0100 elapsed)
(%i6) AinvT : transpose(invert(A))$
Evaluation took 0.4200 seconds (0.4300 elapsed)
(%i7) if dosimp then AinvT : ratsimp(AinvT)$ /* error trigger */
Evaluation took 0.0000 seconds (0.0000 elapsed)
(%i8) zz : [0,-1,0,0]$
Evaluation took 0.0000 seconds (0.0000 elapsed)
(%i9) h1 : transpose(matrix(zz))$
Evaluation took 0.0000 seconds (0.0000 elapsed)
(%i10) h2 : AinvT.h1$
Evaluation took 0.0000 seconds (0.0000 elapsed)
(%i11) h3 : sum(h2[m,1]^2,m,1,d)*detA^2$
Evaluation took 0.0100 seconds (0.0000 elapsed)
(%i12) res : ratsimp(h3)$ /* chokes if trigger is commented */
Evaluation took 8.1200 seconds (8.1300 elapsed)
(%i13) res:ratsimp(h3)$
Evaluation took 8.1900 seconds (8.2100 elapsed)

Tom Dean