On Oct 8, 2007, at 9:34 AM, cwitty wrote:
>
> On Oct 8, 7:36 am, "William Stein" <[EMAIL PROTECTED]> wrote:
>> I do encourage David to open a trac ticket about this. He's right
>> that
>> seeding the random number generator should be possible via a command
>> line argument at startup.
>
> But which random number generator? libc, Python, libpari, NTL,
> libgmp... not counting the many subprocesses that have their own
> random number generator.
>
> I have a rough proposal to try to bring some order to this mess.
> Randomness in SAGE should be centered in a "randgen" object. There is
> a global default randgen, but others can be created. All algorithms
> that use random numbers should take an optional randgen parameter, and
> use the numbers from there. The numbers from a randgen would be
> portable across architectures.
On the face of it, I think it's a good idea. It's worth pursuing, at
least until we have an idea of what the impact is likely to be.
+1
On Oct 8, 2007, at 10:10 AM, William Stein wrote:
> True. However, a few days ago I realized there is a much better
> solution to this problem. Use ... in the output. E.g., instead
> of something like
>
> sage: sin(1.0) # random low-order bits
> 0.841470984807897
>
> we do
>
> sage: sin(1.0)
> 0.8414709848078...
This sounds good, but what about "piping" issues (take the print
output of one function and give it as input to another)? Currently,
we get
sage: xxx= 0.8414709848078...
------------------------------------------------------------
File "<ipython console>", line 1
xxx= RealNumber('0.8414709848078E')llipsis
^
<type 'exceptions.SyntaxError'>: invalid syntax
I often copy/paste between windows running different SAGEs, or even
print to files and read back, so this isn't entirely bogus.
Justin
--
Justin C. Walker, Curmudgeon-At-Large
Institute for the Absorption of Federal Funds
--------
If you're not confused,
You're not paying attention
--------
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to sage-devel@googlegroups.com
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at http://groups.google.com/group/sage-devel
URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/
-~----------~----~----~----~------~----~------~--~---
