ErikP

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7 years, 71 days

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These are replies submitted by ErikP

Hello,

as this issue is a severe obstacle to my calculations (I can not factor reliably over extensions of Q) I was wondering if there is at least some work-around available?

Unfortunately I can not resort to previous or newer versions of Maple.

So in short, is there any (correctly working) way in Maple 16 to factor polynomials over algebraic extensions of the rationals?

Thanks,

Erik

Hello,

as this issue is a severe obstacle to my calculations (I can not factor reliably over extensions of Q) I was wondering if there is at least some work-around available?

Unfortunately I can not resort to previous or newer versions of Maple.

So in short, is there any (correctly working) way in Maple 16 to factor polynomials over algebraic extensions of the rationals?

Thanks,

Erik

Hello,

could anyone else reproduce this error? Otherwise I have to search the problem in my Maple installation.

Thanks,

Erik

Hello,

could anyone else reproduce this error? Otherwise I have to search the problem in my Maple installation.

Thanks,

Erik

Hello,

at last I can reproduce the error reliably. On all four machines I could test it, the following commands result in the error mentioned above upon the very last factors()-call:

L := [t+x[1],t+x[2],t+x[3],x[3]*t+x[2]*x[1],t+x[1]+x[2]+x[3],x[3]*(t+x[1]),x[1]*x[3]+x[2]*t,x[2]+t+x[3],x[2]+x[3],t+x[1]+x[2],x[1]+x[2],x[1]*x[2]+x[3]+t,x[1]*(x[2]+x[3]),x[1]+x[2]+x[3]*t,x[1]*x[3]+(t+x[2])^2]:

K := {I,sqrt(2),sqrt(3),sqrt(5)}:
#K := {sqrt(2),sqrt(3),sqrt(5)}:

for p in L do
  print(p):
  factors(p, K):
end do:

The error disappears when I remove any of the four roots in K (e.g. replacing K by the commented line). Most distractlingly, the error also vanishes upon renaming any of the variables x[1], x[2], x[3] by s (or u or v or ...)!

I have no idea how this is possible and would very much appreciate any help.

 

Thank you and best wishes,

Erik

Note: Removing any of the polynomials in L also makes the error go away.

Hello,

at last I can reproduce the error reliably. On all four machines I could test it, the following commands result in the error mentioned above upon the very last factors()-call:

L := [t+x[1],t+x[2],t+x[3],x[3]*t+x[2]*x[1],t+x[1]+x[2]+x[3],x[3]*(t+x[1]),x[1]*x[3]+x[2]*t,x[2]+t+x[3],x[2]+x[3],t+x[1]+x[2],x[1]+x[2],x[1]*x[2]+x[3]+t,x[1]*(x[2]+x[3]),x[1]+x[2]+x[3]*t,x[1]*x[3]+(t+x[2])^2]:

K := {I,sqrt(2),sqrt(3),sqrt(5)}:
#K := {sqrt(2),sqrt(3),sqrt(5)}:

for p in L do
  print(p):
  factors(p, K):
end do:

The error disappears when I remove any of the four roots in K (e.g. replacing K by the commented line). Most distractlingly, the error also vanishes upon renaming any of the variables x[1], x[2], x[3] by s (or u or v or ...)!

I have no idea how this is possible and would very much appreciate any help.

 

Thank you and best wishes,

Erik

Note: Removing any of the polynomials in L also makes the error go away.

Dear methodology,

thank you very much for pointing this out! I intended to avoid the copying of the table caused by evaluation, as I am considered with particularly huge tables.

I guess the solution would be to pass the variable that shall hold the resulting table as a parameter and avoid using return for the table alltogether?

Best wishes,

ErikP

Dear methodology,

thank you very much for pointing this out! I intended to avoid the copying of the table caused by evaluation, as I am considered with particularly huge tables.

I guess the solution would be to pass the variable that shall hold the resulting table as a parameter and avoid using return for the table alltogether?

Best wishes,

ErikP

Hello again,

I am sure this problem is specific to version 16 of Maple, as clearly such a severe bug would have long been recognised and fixed in earlier versions. In particular note

The PolynomialIdeals[IsRadical], PolynomialIdeals[Radical] and PolynomialIdeals[RadicalMembership] commands were updated in Maple 16.

from the help page ?PolynomialIdeals/IsRadical.

Cheers,

Erik

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