Re: [Numpy-discussion] Manipulate neighboring points in 2D array

2012-12-27 Thread Zachary Pincus
> I have 2D array, let's say: `np.random.random((100,100))` and I want to do > simple manipulation on each point neighbors, like divide their values by 3. > > So for each array value, x, and it neighbors n: > > n n nn/3 n/3 n/3 > n x n -> n/3 x n/3 > n n nn/3 n/3 n/3 > > I searched a

Re: [Numpy-discussion] numpy.testing.asserts and masked array

2012-12-27 Thread Chao YUE
Thanks. I tried again, it works. On Thu, Dec 27, 2012 at 10:35 PM, Ralf Gommers wrote: > from numpy.ma import testutils > -- *** Chao YUE Laboratoire des Sciences du Climat et de l'Environnement (LSCE-IPSL) UMR 15

Re: [Numpy-discussion] numpy.testing.asserts and masked array

2012-12-27 Thread Ralf Gommers
On Thu, Dec 27, 2012 at 12:23 AM, Chao YUE wrote: > Dear all, > > I found here > http://mail.scipy.org/pipermail/numpy-discussion/2009-January/039681.html > that to use* numpy.ma.testutils.assert_almost_equal* for masked array > assertion, but I cannot find the np.ma.testutils module? > Am I gett

[Numpy-discussion] Manipulate neighboring points in 2D array

2012-12-27 Thread deb
Hi, I have 2D array, let's say: `np.random.random((100,100))` and I want to do simple manipulation on each point neighbors, like divide their values by 3. So for each array value, x, and it neighbors n: n n nn/3 n/3 n/3 n x n -> n/3 x n/3 n n nn/3 n/3 n/3 I searched a bit, and found a

Re: [Numpy-discussion] Pre-allocate array

2012-12-27 Thread Chris Barker - NOAA Federal
On Thu, Dec 27, 2012 at 8:44 AM, Nikolaus Rath wrote: > I have an array that I know will need to grow to X elements. However, I > will need to work with it before it's completely filled. what sort of "work with it" do you mean? -- resize() is dangerous if there are any other views on the data bl

[Numpy-discussion] Pre-allocate array

2012-12-27 Thread Nikolaus Rath
Hello, I have an array that I know will need to grow to X elements. However, I will need to work with it before it's completely filled. I see two ways of doing this: bigarray = np.empty(X) current_size = 0 for i in something: buf = produce_data(i) bigarray[current_size:current_size+len(bu

Re: [Numpy-discussion] dtype "reduction"

2012-12-27 Thread Nicolas Rougier
Yep, I'm trying to construct dtype2 programmaticaly and was hoping for some function giving me a "canonical" expression of the dtype. I've started playing with fields but it's just a bit harder than I though (lot of different cases and recursion). Thanks for the answer. Nicolas On Dec 27, 2