# [SciPy-user] Can SciPy compute ln(640320**3 + 744)/163**.5 to 30 places?

Frank Palazzolo palazzol at comcast.net
Mon Jan 15 08:45:20 CST 2007

```Hi,

You should really ask the clnum guy, but I think you need to use exp()
and log() instead of pow().  Also, you have to use only integers.

pow(x,y) = exp(log(x)*y)

from clnum import *
set_default_precision(50)
exp(log(2)*39/10)

which gives:

mpf('14.92852786458891865570149225839907467243567942962390462241',55)

-Frank

Dick Moores wrote:
> I hope I may ask another question. I'd like to know how use clnum to
> calculate 2**3.9 to a precision of 40. I looked carefully at
> http://calcrpnpy.sourceforge.net/clnumManual.html and tried various
> things, but to no avail.
>
> Despite these words in the manual:
>
> "Most of the functions in the clnum module are arbitrary precision
> floating point versions of Python builtins. See the Python
> documentation in the math, cmath, and builtins sections for the
> following functions: acos, acosh, asin, asinh, atan, atan2, atanh,
> ceil, cos, cosh, degrees, exp, floor, hypot, log, log10, radians,
> round, sin, sinh, sqrt, tan, and tanh."
>
> it seems there is no clnum.pow(). Help, please.
>
> Thanks,
>
> Dick Moores
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>

```