Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.python > #41162

Re: How can i create a random array of floats from 0 to 5 in python

Show key headers only | View raw

On Tuesday, March 12, 2013 2:59:29 PM UTC-7, Oscar Benjamin wrote:
> On 12 March 2013 20:21, llanitedave <llanitedave@veawb.coop> wrote:
> 
> > On Tuesday, March 12, 2013 10:47:25 AM UTC-7, Maarten wrote:
> 
> >> On Tuesday, March 12, 2013 6:11:10 PM UTC+1, Norah Jones wrote:
> 
> >>
> 
> >> > I want to create a random float array of size 100, with the values in the array ranging from 0 to 5. I have tried random.sample(range(5),100) but that does not work. How can i get what i want to achieve?
> 
> >>
> 
> >> Use numpy
> 
> [SNIP]
> 
> >
> 
> > While numpy would work, I fail to see how encouraging the op to download and install a separate library and learn a whole new set of tools would be beneficial by default, without knowing the purpose of the need.  This is like recommending an RPG to fix a sticky door hinge.
> 
> 
> 
> This suggestion comes after others that show how to use the stdlib's
> 
> random module. I don't think it's unreasonable to recommend numpy for
> 
> this. If you want to create *arrays* of random numbers then why not
> 
> use a library that provides an API specifically for that? You can test
> 
> yourself to see that numpy is 10x faster for large arrays:
> 
> 
> 
> Python 2.7 on Linux:
> 
> $ python -m timeit -s 'import random' -- '[random.uniform(0, 5) for x
> 
> in range(1000)]'
> 
> 1000 loops, best of 3: 729 usec per loop
> 
> $ python -m timeit -s 'import random' -- '[random.random() * 5 for x
> 
> in range(1000)]'
> 
> 1000 loops, best of 3: 296 usec per loop
> 
> $ python -m timeit -s 'import numpy' -- 'numpy.random.uniform(0, 5, 1000)'
> 
> 10000 loops, best of 3: 32.2 usec per loop
> 
> 
> 
> I would use numpy for this mainly because if I'm creating arrays of
> 
> random numbers I probably want to use them in ways that are easier
> 
> with numpy arrays. There's also a chance the OP might benefit more
> 
> generally from using numpy depending on what they're working on.
> 
> 
> 
> 
> 
> Oscar

I don't think numpy is unreasonable for you or me.  I just started learning it recently, and I'm pretty jazzed about its possibilities.  I obtained an app for work that uses it, and now it's up to me to maintain it, so learning it is a good idea for me regardless.  Now I'm starting to fantasize about other things I could do with it.

But the OP appears like a pretty basic beginner, and I really think that for such a entry-level knowledge scale, we should stick to the standard library until they're ready to take on more sophisticated tasks.  "Premature Optimization" is the analogy that comes to mind.

Back to comp.lang.python | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

How can i create a random array of floats from 0 to 5 in python Norah Jones <nh.jones01@gmail.com> - 2013-03-12 17:11 +0000
  Re: How can i create a random array of floats from 0 to 5 in python Maarten <maarten.sneep@knmi.nl> - 2013-03-12 10:47 -0700
    Re: How can i create a random array of floats from 0 to 5 in python llanitedave <llanitedave@veawb.coop> - 2013-03-12 13:21 -0700
      Re: How can i create a random array of floats from 0 to 5 in python Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-03-12 21:59 +0000
        Re: How can i create a random array of floats from 0 to 5 in python llanitedave <llanitedave@veawb.coop> - 2013-03-12 22:35 -0700
        Re: How can i create a random array of floats from 0 to 5 in python llanitedave <llanitedave@veawb.coop> - 2013-03-12 22:35 -0700
    Re: How can i create a random array of floats from 0 to 5 in python llanitedave <llanitedave@veawb.coop> - 2013-03-12 13:21 -0700
  Re: How can i create a random array of floats from 0 to 5 in python Maarten <maarten.sneep@knmi.nl> - 2013-03-12 10:47 -0700

csiph-web