[zakad]

python 2.5.2
ubuntu 8.04 LTS

(1) I find that python/gmpy is about 3 times slower than c++/gmp.
Is this the general experience, or am I doing something wrong?

(2) I am unable to understand the following error in conversion from float() to gmpy.mpf() or how to avoid it:

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1. import gmpy
2. gmpy.set_minprec(100)
3. t= gmpy.mpf(7.99)
4. print t
5. print t/3
6.  

prints:
7.990000000000000213162820728030055761337
2.663333333333333404387606909343351920446

I am new to both linux and python and would appreciate any expert help.

zakad

[casevh]

Hi,

Can you provide an example for performance question?

Python will have more overhead for each function call, so it will be slower when making multiple calls. The amount of slowdown should decrease as the size of the numbers increases.

Regarding your conversion question, you are converting the floating point approximation to 7.99 which is only accurate to about 18 decimal digits. If you convert the string "7.99" to an mpf, you'll get the value that I think you are expecting.

casevh