random number including 1 - i.e. [0,1]
mensanator at aol.com
Wed Jun 10 01:54:21 EDT 2009
On Jun 9, 11:28�pm, Steven D'Aprano
<ste... at REMOVE.THIS.cybersource.com.au> wrote:
> On Tue, 09 Jun 2009 21:04:49 -0700, Mensanator wrote:
> > On Jun 9, 8:28 pm, John Yeung <gallium.arsen... at gmail.com> wrote:
> >> On Jun 9, 8:45 pm, Mensanator <mensana... at aol.com> wrote:
> >> > On Jun 9, 6:05 pm, "Gabriel Genellina" <gagsl-... at yahoo.com.ar>
> >> > wrote:
> >> > > py> a+(b-a)*z < b # the expression used for uniform(a,b) False
> >> > > py> a+(b-a)*z
> >> > > 11.0
> >> > What you do with the number after it's created is not random's
> >> > concern.
> >> Mensanator, you missed Gabriel's point. What he's saying is that,
> >> effectively, random.uniform(a, b) returns a + (b - a) * random.random
> >> (). So z may not be random()'s concern, but it very much is uniform
> >> ()'s concern.
> >> > > The docs are already updated to reflect
> >> > > this:http://svn.python.org/view/python/trunk/Doc/library/
> >> > The docs are now wrong. Why would they do that?
> >> The docs are now... sort of correct.
> > I'm not actually disputing that.
> Funny, saying "The docs are now wrong" sure sounds like you're disputing
> that they're correct to me!
Those statements were made over two hours apart.
Things can change in two hours.
> > I'm simply puzzled why this issue was
> > swept under the rug by pretending it's supposed to work that way.
> I'm completely confused. What is "this issue",
[0,1) vs. [0,1]
> and why are we
> "pretending" that it's supposed to work "that way"?
By changing the documentation without explaining why.
If the intention was [0,1), as implied by the 2.6.1 docs,
but wasn't actually doing that, it should be so stated.
This isn't simply fixing a typo.
> Yes, I've read the thread. I still have no idea what you are complaining
According to your reply to John Young, you know exactly
what the problem is.
> > We're
> > not children here, you can explain that what is supposed to work in
> > theory sometimes has problems in practice. We're not all going to
> > abandon Python and run out and buy Mathematica.
> > Look at how the change of random to the Mersenne Twister was handled.
> > That's what we, the users, want to see.
> Speak for yourself. What about the change that you think "we, the users",
> want to see?
Things like this: "Python uses the Mersenne Twister
as the core generator. It produces 53-bit precision
floats and has a period of 2**19937-1. The underlying
implementation in C is both fast and threadsafe.
The Mersenne Twister is one of the most extensively
tested random number generators in existence."
Is that strictly necessary in the random documentation
that defines what the random module does? _I_ appreciate
it being there and am glad someone made the effort to
put it there. If there is a change from a<=N<b to
a<=N<=b I would like to see that pointed out also,
even if it isn't strictly part of the definition of
what the function does.
> > Otherwise, it creates endless confusion.
> Not as confused as this discussion.
I thought you said you read the thread?
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