[Numpy-discussion] NaN (Not a Number) occurs in calculation of complex number for Bessel functions

Happyman bahtiyor_zohidov@mail...
Fri Dec 21 13:44:10 CST 2012


 Thanks

But I could find for Win64 bit windows????
Second question: Did you mean that I have to put lens limits of those number???  


Пятница, 21 декабря 2012, 15:45 UTC от Pauli Virtanen <pav@iki.fi>:
>Hi,
>
>Your code tries to to evaluate
>
>    z = 1263309.3633394379 + 101064.74910119522j
>    jv(536, z)
>    # -> (inf+inf*j)
>
>In reality, this number is not infinite, but
>
>    jv(536, z) == -2.3955170861527422e+43888 + 9.6910119847300024e+43887
>
>These numbers (~ 10^43888) are too large for the floating point
>numbers that computers use (maximum ~ 10^308). This is why you get
>infinities and NaNs in the result. The same is true for the spherical
>Bessel functions.
>
>You will not be able to do this calculation using any software
>that uses only floating point numbers (Scipy, Matlab, ...).
>
>You need to use analytical properties of your problem to
>get rid of such large numbers. Alternatively, you can use arbitrary
>precision numbers. Python has libraries for that:
>
>http://code.google.com/p/mpmath/
>
>
>By the way, the proper place for this discussion is the following
>mailing list:
>
>http://mail.scipy.org/mailman/listinfo/scipy-user
>
>-- 
>Pauli Virtanen
>
>
>_______________________________________________
>NumPy-Discussion mailing list
>NumPy-Discussion@scipy.org
>http://mail.scipy.org/mailman/listinfo/numpy-discussion

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mail.scipy.org/pipermail/numpy-discussion/attachments/20121221/0d878051/attachment.html 


More information about the NumPy-Discussion mailing list