Compute pi to base 12 using Python?

[Dick Moores]

I need to figure out how to compute pi to base 12, to as many digits as
possible. I found this reference,
<http://mathworld.wolfram.com/Base.html>, but I really don't understand
it well enough. Could someone show me how to do what I need?

Thanks,

Dick Moores
rd*@rcblue.com

[M.E.Farmer]

>>PS. Redirecting with > from a script whose interpreter was started by

windows extension association
doesn't work on some version of windows. To be safe, invoke the
interpreter explicitly, e.g.,
python myscript.py [whatever args here] > pi3003.txt

Thanks very much for this.
What kind of args could I use here?

Any that your script allows or understands.
an example:
python c:/Python22/Lib/PySourceColor.py -i- -s -l < c:/MyFile.py >
c:/tmp/myfile.html

A few things that might help you write a well behaved script:
if sys.stdin.isatty():
"direct"
else:
"redirected"
This snippet can determine if you have redirected IO.

I just found this and it looks informative.
http://www.jpsdomain.org/windows/redirection.html

hth,
M.E.Farmer

[Nick Craig-Wood]

me********@aol.com <me********@aol.com> wrote:

Nick Craig-Wood wrote:

me********@aol.com <me********@aol.com> wrote:

I'm using GMPY (see code).

[snip]

If you are using gmpy you might as well do it like this.....

gmpy.pi() uses the Brent-Salamin Arithmetic-Geometric Mean formula
for
pi IIRC. This converges quadratically, and it will calculate you a
million places without breaking a sweat.

It would be nice if that were documented. What do I have to do, go get
the documentation for the original GMP to find out what else is in GMPY
that they didn't include in the doc file?

"pydoc gmpy" works for me. Not sure how you use pydoc on windows, but
you can do this...

import gmpy
help(gmpy)

Help on module gmpy:

NAME
gmpy

FILE
/usr/lib/python2.3/site-packages/gmpy.so
[snip]
Help on built-in function pi:

pi(...)
pi(n): returns pi with n bits of precision in an mpf object
[snip]

The original gmp documentation is sensible also, since gmpy is really
just a thin wrapper to it. There is also the gmp source code too.

--
Nick Craig-Wood <ni**@craig-wood.com> -- http://www.craig-wood.com/nick

[mensanator]

Nick Craig-Wood wrote:

me********@aol.com <me********@aol.com> wrote:

Nick Craig-Wood wrote:

me********@aol.com <me********@aol.com> wrote:
> I'm using GMPY (see code).
[snip]

If you are using gmpy you might as well do it like this.....

gmpy.pi() uses the Brent-Salamin Arithmetic-Geometric Mean formula for
pi IIRC. This converges quadratically, and it will calculate you a million places without breaking a sweat.
It would be nice if that were documented. What do I have to do, go get

the documentation for the original GMP to find out what else is in GMPY that they didn't include in the doc file?

"pydoc gmpy" works for me. Not sure how you use pydoc on windows,

but you can do this...
import gmpy
help(gmpy) Help on module gmpy:

NAME
gmpy

FILE
/usr/lib/python2.3/site-packages/gmpy.so
[snip]
Help on built-in function pi:

pi(...)
pi(n): returns pi with n bits of precision in an mpf object
[snip]
Thanks, didn't know you could do that. And I'm glad you didn't reply
until today, because I learned how to do it the hard way:

import gmpy
f = dir(gmpy)
def print_docs(f): for q in f:
if q[:2]=='__':
pass
else:
d = 'gmpy.' + q + '.__doc__'
e = eval(compile(d,'<string>','eval')
print e
print print_docs(f)

That's 3 new functions I learned, dir(), compile() and eval().
And now that I know help(), I'll probably never need them, but
hopefully will remember them.

Even better, I realize the inadequecy of the doc strings of a
program I wrote. Now that I know how to use them interactively,
I can make them more useful.

The original gmp documentation is sensible also, since gmpy is really
just a thin wrapper to it.
I already looked. Utterly useless.
There is also the gmp source code too.
That helped, as there's a list of the function names in the source
code, but help() makes it unnecessary.

You still have to wonder, though, with as easy as this is, how the
gmpy documention ended up incomplete. I'm always reminded of something
I read in the National Lampoon:

"You know what a fuck-up you are at work, how would anything get
done if everyone was like you? Well, the sad fact is everyone _is_
just like you...including the air traffic controller who's supposed
to be tracking your flight but has just looked away because he
dropped a cigarette ash and burned a hole in his trousers..."

So I suppose I shouldn't complain, after all, I got something
positive out of it.

--
Nick Craig-Wood <ni**@craig-wood.com> --

http://www.craig-wood.com/nick