Re: [Numpy-discussion] sparse array data

2012-05-02 Thread Travis Oliphant
On May 2, 2012, at 10:03 PM, Stéfan van der Walt wrote: > On Wed, May 2, 2012 at 6:25 PM, Travis Oliphant wrote: >> The only new principle (which is not strictly new --- but new to NumPy's >> world-view) is using one (or more) fields of a structured array as >> "synthetic dimensions" which rep

Re: [Numpy-discussion] sparse array data

2012-05-02 Thread Charles R Harris
On Wed, May 2, 2012 at 3:20 PM, Nathaniel Smith wrote: > On Wed, May 2, 2012 at 9:53 PM, Francesc Alted > wrote: > > On 5/2/12 11:16 AM, Wolfgang Kerzendorf wrote: > >> Hi all, > >> > >> I'm currently writing a code that needs three dimensional data (for the > physicists it's dimensions are atom

Re: [Numpy-discussion] sparse array data

2012-05-02 Thread Stéfan van der Walt
On Wed, May 2, 2012 at 6:25 PM, Travis Oliphant wrote: > The only new principle (which is not strictly new --- but new to NumPy's > world-view) is using one (or more) fields of a structured array as "synthetic > dimensions" which replace 1 or more of the raw table dimensions. Ah, thanks--that's

Re: [Numpy-discussion] record arrays initialization

2012-05-02 Thread Aronne Merrelli
On Wed, May 2, 2012 at 6:46 PM, Kevin Jacobs wrote: > On Wed, May 2, 2012 at 7:25 PM, Aronne Merrelli > wrote: >> >> In general this is a good suggestion - I was going to mention it >> earlier - but I think for this particular problem it is not better >> than the "brute force" and argmin() NumPy

Re: [Numpy-discussion] record arrays initialization

2012-05-02 Thread Benjamin Root
On Wednesday, May 2, 2012, Stéfan van der Walt wrote: > On Wed, May 2, 2012 at 4:46 PM, Kevin Jacobs > > > > > wrote: > > A FLANN implementation should be even faster--perhaps by as much as > another > > factor of two. > > I guess it depends on whether you care about the "Approximate" in > "Fast

Re: [Numpy-discussion] record arrays initialization

2012-05-02 Thread Stéfan van der Walt
On Wed, May 2, 2012 at 4:46 PM, Kevin Jacobs wrote: > A FLANN implementation should be even faster--perhaps by as much as another > factor of two. I guess it depends on whether you care about the "Approximate" in "Fast Library for Approximate Nearest Neighbors". Stéfan _

Re: [Numpy-discussion] record arrays initialization

2012-05-02 Thread Stéfan van der Walt
On Wed, May 2, 2012 at 4:26 PM, Moroney, Catherine M (388D) wrote: > Using structured arrays is making my code complex when I try to call the > vectorized function.  If I stick to the original record arrays, what's the > best way of initializing b from a without doing an row-by-row copy? What doe

Re: [Numpy-discussion] sparse array data

2012-05-02 Thread Travis Oliphant
On May 2, 2012, at 5:28 PM, Stéfan van der Walt wrote: > On Wed, May 2, 2012 at 3:20 PM, Francesc Alted wrote: >> On 5/2/12 4:07 PM, Stéfan van der Walt wrote: >> Well, as the OP said, coo_matrix does not support dimensions larger than >> 2, right? > > That's just an implementation detail, I wo

Re: [Numpy-discussion] record arrays initialization

2012-05-02 Thread Kevin Jacobs
On Wed, May 2, 2012 at 7:25 PM, Aronne Merrelli wrote: > In general this is a good suggestion - I was going to mention it > earlier - but I think for this particular problem it is not better > than the "brute force" and argmin() NumPy approach. On my laptop, the > KDTree query is about a factor of

[Numpy-discussion] record arrays initialization

2012-05-02 Thread Moroney, Catherine M (388D)
On May 2, 2012, at 3:23 PM, wrote: >> A) ?How do I most efficiently construct a record array from a single array? >> I want to do the following, but it segfaults on me when i try to print b. >> >> vtype = [("x", numpy.ndarray)] >> a = numpy.arange(0, 16).reshape(4,4) >> b = numpy.recarray((4)

Re: [Numpy-discussion] record arrays initialization

2012-05-02 Thread Aronne Merrelli
On Wed, May 2, 2012 at 5:27 PM, Kevin Jacobs wrote: > On Wed, May 2, 2012 at 5:45 PM, Moroney, Catherine M (388D) > wrote: >> >> Thanks to Perry for some very useful off-list conversation.   I realize >> that >> I wasn't being clear at all in my earlier description of the problem so >> here it i

Re: [Numpy-discussion] sparse array data

2012-05-02 Thread Nathaniel Smith
On Wed, May 2, 2012 at 11:26 PM, Francesc Alted wrote: > On 5/2/12 4:20 PM, Nathaniel Smith wrote: >> On Wed, May 2, 2012 at 9:53 PM, Francesc Alted  wrote: >>> On 5/2/12 11:16 AM, Wolfgang Kerzendorf wrote: Hi all, I'm currently writing a code that needs three dimensional data (for

Re: [Numpy-discussion] Test failures - which dependencies am I missing?

2012-05-02 Thread Chris Ball
Chris Ball gmail.com> writes: > > Keith Hughitt gmail.com> writes: > > > Hi Chris, > > > > Try "sudo apt-get build-dep python-numpy" to install the dependencies for > > building NumPy. I believe it will install all of the optional dependencies > > as well. > > Thanks for that, but I'd alrea

Re: [Numpy-discussion] sparse array data

2012-05-02 Thread Francesc Alted
On 5/2/12 5:28 PM, Stéfan van der Walt wrote: > On Wed, May 2, 2012 at 3:20 PM, Francesc Alted wrote: >> On 5/2/12 4:07 PM, Stéfan van der Walt wrote: >> Well, as the OP said, coo_matrix does not support dimensions larger than >> 2, right? > That's just an implementation detail, I would imagine--I

Re: [Numpy-discussion] sparse array data

2012-05-02 Thread Stéfan van der Walt
On Wed, May 2, 2012 at 3:20 PM, Francesc Alted wrote: > On 5/2/12 4:07 PM, Stéfan van der Walt wrote: > Well, as the OP said, coo_matrix does not support dimensions larger than > 2, right? That's just an implementation detail, I would imagine--I'm trying to figure out if there is a new principle

Re: [Numpy-discussion] record arrays initialization

2012-05-02 Thread Kevin Jacobs
On Wed, May 2, 2012 at 5:45 PM, Moroney, Catherine M (388D) < catherine.m.moro...@jpl.nasa.gov> wrote: > Thanks to Perry for some very useful off-list conversation. I realize > that > I wasn't being clear at all in my earlier description of the problem so > here it is > in a nutshell: > > Find t

Re: [Numpy-discussion] sparse array data

2012-05-02 Thread Francesc Alted
On 5/2/12 4:20 PM, Nathaniel Smith wrote: > On Wed, May 2, 2012 at 9:53 PM, Francesc Alted wrote: >> On 5/2/12 11:16 AM, Wolfgang Kerzendorf wrote: >>> Hi all, >>> >>> I'm currently writing a code that needs three dimensional data (for the >>> physicists it's dimensions are atom, ion, level). The

Re: [Numpy-discussion] record arrays initialization

2012-05-02 Thread Stéfan van der Walt
On Wed, May 2, 2012 at 2:45 PM, Moroney, Catherine M (388D) wrote: > Find the best match in an array t(5000, 7) for a single vector e(7).  Now > scale > it up so e is (128, 512, 7) and I want to return a (128, 512) array of the > t-identifiers > that are the best match for e.  "Best match" is de

Re: [Numpy-discussion] sparse array data

2012-05-02 Thread Francesc Alted
On 5/2/12 4:07 PM, Stéfan van der Walt wrote: > Hi Francesc > > On Wed, May 2, 2012 at 1:53 PM, Francesc Alted wrote: >> and add another one for the actual values of the array. For a 3-D >> sparse array, this looks like: >> >> dim0 | dim1 | dim2 | value >> == >> 0 |

Re: [Numpy-discussion] Continuous Integration

2012-05-02 Thread Chris Ball
David Froger gmail.com> writes: > > I've been working on setting up a new buildbot for > > NumPy. Unfortunately, I don't have much time to work on it, > > so it's slow going! ... > Hi, > > If there are things one can contribute to help the development > of the buildbot for NumPy, I would be ha

Re: [Numpy-discussion] record arrays and vectorizing

2012-05-02 Thread Aronne Merrelli
On Wed, May 2, 2012 at 1:06 PM, Moroney, Catherine M (388D) wrote: > Hello, > > Can somebody give me some hints as to how to code up this function > in pure python, rather than dropping down to Fortran? > > I will want to compare a 7-element vector (called "element") to a large list > of similarl

[Numpy-discussion] record arrays initialization

2012-05-02 Thread Moroney, Catherine M (388D)
Thanks to Perry for some very useful off-list conversation. I realize that I wasn't being clear at all in my earlier description of the problem so here it is in a nutshell: Find the best match in an array t(5000, 7) for a single vector e(7). Now scale it up so e is (128, 512, 7) and I want to

Re: [Numpy-discussion] Issue Tracking

2012-05-02 Thread Wes McKinney
On Wed, May 2, 2012 at 9:48 AM, Charles R Harris wrote: > > > On Tue, May 1, 2012 at 11:47 PM, Ralf Gommers > wrote: >> >> >> >> On Wed, May 2, 2012 at 1:48 AM, Pauli Virtanen wrote: >>> >>> 01.05.2012 21:34, Ralf Gommers kirjoitti: >>> [clip] >>> > At this point it's probably good to look again

Re: [Numpy-discussion] sparse array data

2012-05-02 Thread Nathaniel Smith
On Wed, May 2, 2012 at 9:53 PM, Francesc Alted wrote: > On 5/2/12 11:16 AM, Wolfgang Kerzendorf wrote: >> Hi all, >> >> I'm currently writing a code that needs three dimensional data (for the >> physicists it's dimensions are atom, ion, level). The problem is that not >> all combinations do exis

Re: [Numpy-discussion] sparse array data

2012-05-02 Thread Stéfan van der Walt
Hi Francesc On Wed, May 2, 2012 at 1:53 PM, Francesc Alted wrote: > and add another one for the actual values of the array.  For a 3-D > sparse array, this looks like: > > dim0 | dim1 | dim2 | value > == >    0 |   0  |   0  | val0 >    0 |  10  | 100  | val1 >   20 |   5

Re: [Numpy-discussion] Continuous Integration

2012-05-02 Thread David Froger
> I've been working on setting up a new buildbot for NumPy. Unfortunately, I > don't have much time to work on it, so it's slow going! Right now I am still > at > the stage of getting NumPy to pass all its tests on the machines I'm using as > test slaves. After that, I plan to transfer existing

Re: [Numpy-discussion] sparse array data

2012-05-02 Thread Francesc Alted
On 5/2/12 11:16 AM, Wolfgang Kerzendorf wrote: > Hi all, > > I'm currently writing a code that needs three dimensional data (for the > physicists it's dimensions are atom, ion, level). The problem is that not all > combinations do exist (a sparse array). Sparse matrices in scipy only deal > with

Re: [Numpy-discussion] copying array to itself

2012-05-02 Thread Stéfan van der Walt
On Wed, May 2, 2012 at 9:03 AM, Henry Gomersall wrote: > Is this some nuance of the way numpy does things? Or am I missing some > stupid bug in my code? Try playing with the parameters of the following code: sz = 1 N = 10 import numpy as np x = np.arange(sz) y = x.copy() x[:-N] = x[N:] np

Re: [Numpy-discussion] record arrays and vectorizing

2012-05-02 Thread Stéfan van der Walt
On Wed, May 2, 2012 at 11:06 AM, Moroney, Catherine M (388D) wrote: > I will want to compare a 7-element vector (called "element") to a large list > of similarly-dimensioned > vectors (called "target", and pick out the vector in "target" that is the > closest to "element" > (determined by minimi

[Numpy-discussion] record arrays and vectorizing

2012-05-02 Thread Moroney, Catherine M (388D)
Hello, Can somebody give me some hints as to how to code up this function in pure python, rather than dropping down to Fortran? I will want to compare a 7-element vector (called "element") to a large list of similarly-dimensioned vectors (called "target", and pick out the vector in "target" that

Re: [Numpy-discussion] sparse array data

2012-05-02 Thread Frédéric Bastien
what about numpy.ma? Those are marked array. But they won't be the fastest. Fred On Wed, May 2, 2012 at 12:16 PM, Wolfgang Kerzendorf wrote: > Hi all, > > I'm currently writing a code that needs three dimensional data (for the > physicists it's dimensions are atom, ion, level). The problem is t

[Numpy-discussion] sparse array data

2012-05-02 Thread Wolfgang Kerzendorf
Hi all, I'm currently writing a code that needs three dimensional data (for the physicists it's dimensions are atom, ion, level). The problem is that not all combinations do exist (a sparse array). Sparse matrices in scipy only deal with two dimensions. The operations that I need to do on those

[Numpy-discussion] copying array to itself

2012-05-02 Thread Henry Gomersall
I'm need to do some shifting of data within an array and am using the following code: for p in numpy.arange(array.shape[0], dtype='int64'): for q in numpy.arange(array.shape[1]): # A positive shift is towards zero shift = shift_values[p, q] if shift >= 0:

Re: [Numpy-discussion] Issue Tracking

2012-05-02 Thread Charles R Harris
On Tue, May 1, 2012 at 11:47 PM, Ralf Gommers wrote: > > > On Wed, May 2, 2012 at 1:48 AM, Pauli Virtanen wrote: > >> 01.05.2012 21:34, Ralf Gommers kirjoitti: >> [clip] >> > At this point it's probably good to look again at the problems we want >> > to solve: >> > 1. responsive user interface (m