In <[EMAIL PROTECTED]>, Michael M. wrote:
> * The C is very fast, Python not.
> * Target: Do optimization, that Python runs nearly like C.
As someone else already asked: Why? You can't beat a compiled to machine
code language with an interpreted one when doing integer arithmetic.
> counter=c
> while 0<=counter+4000:
> f.append(2000) # f.append( int(a/5) )
> counter=counter-1
> # b=b+1
Why do you count so complicated here? It's hard to see that this creates
a list with 2801 elements.
> d = int(d/g) ## needs cast to int
Instead of converting the numbers to float by "real" division and then
converting back the result you should do integer division:
d = d // g
or
d //= g
> pi = pi + str("%04d" % int(e + d/a))
The `str()` call is unnecessary. And again: try to stick to integer
arithmetic with ``//``.
Here is my attempt to convert the C code, not written with speed in mind
and I was too lazy too time it. :-)
from itertools import izip
def pi():
result = list()
d = 0
e = 0
f = [2000] * 2801
for c in xrange(2800, 0, -14):
for b, g in izip(xrange(c, 1, -1), xrange((c * 2) - 1, 0, -2)):
d += f[b] * 10000
h, f[b] = divmod(d, g)
d = h * b
h, i = divmod(d, 10000)
result.append('%.4d' % (e + h))
e = i
return ''.join(result)
Ciao,
Marc 'BlackJack' Rintsch
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