[SciPy-dev] Exact calculation
Pearu Peterson
pearu at cens.ioc.ee
Fri Nov 1 09:25:51 CST 2002
On 31 Oct 2002, Travis Oliphant wrote:
>
> What is the feeling of this group about adding some kind of
> exact real number calculation module to scipy.
I am positive about it, really.
> I know there is a wrapping of the gnu multiprecision library that is
> GPL.
>
> But, there is an excellent self-contained module called real.py that is
> completely free (no expressed copyright) By Jurjen N.E. Bos
> (jurjen at q2c.nl).
real.py looks very nice (shows errors, has various elementary
functions, has docs but no unittests:( etc.) but it is dead slow compared
to GMPY. I would hope that in scipy we could have more efficient and
longer lasting tools for exact calculation than real.py.
For example,
peterson at utmws130:~/tmp > python bench_exact.py
real.py:101: DeprecationWarning: the regex module is deprecated; please
use the re module
import math, regex, marshal, string, sys
gmpy float multiplication took 3600.00 secs
real float multiplication took 107000.00 secs
where
# file bench_real.py
from scipy_test.testing import jiffies
import gmpy
import real
gmpy.set_minprec(80)
real.floatPrecision=80
n=100000
a1 = 1/gmpy.mpf('3')
a2 = 1/real.r(3)
i = n
st=jiffies()
while i:
i -= 1
a1*a1
et=jiffies()
print 'gmpy float multiplication took %.2f secs' % (100*(et-st))
i = n
st=jiffies()
while i:
i -= 1
a2*a2
et=jiffies()
print 'real float multiplication took %.2f secs' % (100*(et-st))
# eof
More information about the Scipy-dev
mailing list