possibly trivial newbie list/array question

[Emile van Sebille]

Look into NumPy.

--

Emile van Sebille
emile at fenx.com

---------
"Michael Williams" <michael.williams at st-annes.ox.ac.uk> wrote in message
news:f3ccacbf.0108211646.28793074 at posting.google.com...
> Hi,
>
> Sorry if this question has been done to death but my friend Mr Google
> Groups wasn't able to point me in the direction of the answer.
>
> I'm an undergraduate doing a relatively simple bit of functional
> programming, looking at the behaviour of Lorenz attractors. My
> department recommends (or uses as standard) Pascal. I'd rather avoid
> this, and Python is something I've been looking into.
>
> (Amongst other things!) what I want to do is multiply an array of
> floating points numbers with a float elementwise, i.e.
>
> >>> [1.0, 2.0, 3.0] * 4.0
> [4.0, 8.0, 12.0]
>
> Of course this is not the usual behaviour of lists, which is to repeat
> the list making a 12 object list in that example. The obvious way that
> struck me to do this was simply to step through the list by index,
> multiplying each element "manually", to wit:
>
> array1 = [1.0, 2.0, 3.0]
> for i in len(array1):
>     array1[i] = array1[i] * 4.0
>
> The program will do this operation a lot so I'm concerned that this
> should be the most efficient way of doing this. Is it? My arrays are
> relatively small (~10^2 elements). I looked at NumPy's array() object
> and the array module that comes with a standard installation as
> solutions and they both seem to fit the bill too. Is using either of
> these an unecessariy complex/slow way of doing this (and only this)?
>
> Thanks for any advice,
>
> --
> Michael Williams