Hello,

some months ago I started using sympy for finding roots of polynomials.
It works really well and it enables me to solve more and more complicated 
problems.

Recently, I observed a case where the function sympy.intervals(...) throws 
an "OverflowError" exception.
It happens when executing the following commands:

import sympy

a = "(x**45 - 45*x**44 + 990*x**43 - 1)"

b = "(x**46 - 15180*x**43 + 9366819*x**40 - 53524680*x**39 + 
260932815*x**38 - 1101716330*x**37 + 4076350421*x**36 - 13340783196*x**35 + 
38910617655*x**34 - 101766230790*x**33 + 239877544005*x**32 - 
511738760544*x**31 + 991493848554*x**30 - 1749695026860*x**29 + 
2818953098830*x**28 - 4154246671960*x**27 + 5608233007146*x**26 - 
6943526580276*x**25 + 7890371113950*x**24 - 8233430727600*x**23 + 
7890371113950*x**22 - 6943526580276*x**21 + 5608233007146*x**20 - 
4154246671960*x**19 + 2818953098830*x**18 - 1749695026860*x**17 + 
991493848554*x**16 - 511738760544*x**15 + 239877544005*x**14 - 
101766230790*x**13 + 38910617655*x**12 - 13340783196*x**11 + 
4076350421*x**10 - 1101716330*x**9 + 260932815*x**8 - 53524680*x**7 + 
9366819*x**6 - 1370754*x**5 + 163185*x**4 - 15180*x**3 + 1035*x**2 - 47*x + 
1)"

sympy.intervals( a + "*" + b )


Of course, in this particular case, the exception could be avoided if 
sympy.intervals() is called for a and b separately.
However, since I run a very large number of similar computations, I am not 
so much interested in how to solve this particular problem.
Instead, I am interested in why this exception is raised at all. Is it due 
to a limitation of sympy.intervals()? Or maybe a bug? Or do I use it 
incorrectly?
What I observed so far is that the above code raises an "OverflowError" 
exception when function dup_root_upper_bound() tries to compute 2.0**1041, 
which obviously must fail.

Any help is appreciated.

Best regards,
Heiner







-- 
You received this message because you are subscribed to the Google Groups 
"sympy" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/sympy.
For more options, visit https://groups.google.com/groups/opt_out.

Reply via email to