Re: [Numpy-discussion] Simple problem. Is it possible without a loop?

2010-06-10 Thread V. Armando Solé
Hi Bruce, In the context of the actual problem, I have a long series of non-equidistant and irregularly spaced float numbers and I have to take values between given limits with the constraint of keeping a minimal separation. Option 2 just misses the first value of the input array if it is

Re: [Numpy-discussion] yet another scipy Install problem

2010-06-10 Thread David Cournapeau
On Thu, Jun 10, 2010 at 1:16 PM, Bino Oetomo b...@indoakses-online.com wrote: Dear All .. I tried to install numpy and scipy ... basicaly I want to use OMPC You need at least numpy 1.4 to build scipy from current svn, David ___ NumPy-Discussion

Re: [Numpy-discussion] NumPy re-factoring project

2010-06-10 Thread Charles R Harris
On Wed, Jun 9, 2010 at 5:27 PM, Jason McCampbell jmccampb...@enthought.comwrote: Hi everyone, This is a follow-up to Travis's message on the re-factoring project from May 25th and the subsequent discussion. For background, I am a developer at Enthought working on the NumPy re-factoring

Re: [Numpy-discussion] NumPy re-factoring project

2010-06-10 Thread Charles R Harris
On Thu, Jun 10, 2010 at 7:26 AM, Charles R Harris charlesr.har...@gmail.com wrote: On Wed, Jun 9, 2010 at 5:27 PM, Jason McCampbell jmccampb...@enthought.com wrote: Hi everyone, This is a follow-up to Travis's message on the re-factoring project from May 25th and the subsequent

Re: [Numpy-discussion] NumPy re-factoring project

2010-06-10 Thread Jason McCampbell
Hi Chuck, Good questions. Responses inline below... Jason On Thu, Jun 10, 2010 at 8:26 AM, Charles R Harris charlesr.har...@gmail.com wrote: On Wed, Jun 9, 2010 at 5:27 PM, Jason McCampbell jmccampb...@enthought.com wrote: Hi everyone, This is a follow-up to Travis's message on the

Re: [Numpy-discussion] NumPy re-factoring project

2010-06-10 Thread Sturla Molden
I have a few radical suggestions: 1. Use ctypes as glue to the core DLL, so we can completely forget about refcounts and similar mess. Why put manual reference counting and error handling in the core? It's stupid. 2. The core should be a plain DLL, loadable with ctypes. (I know David

Re: [Numpy-discussion] NumPy re-factoring project

2010-06-10 Thread Sturla Molden
Den 10.06.2010 18:48, skrev Sturla Molden: ctypes will also make porting to other Python implementations easier (or even other languages: Ruby, JacaScript) easier. Not to mention that it will make NumPy impervious to changes in the Python C API. Linking is also easier with ctypes. I started

Re: [Numpy-discussion] NumPy re-factoring project

2010-06-10 Thread Sturla Molden
Another suggestion I'd like to make is bytearray as memory buffer for the ndarray. An ndarray could just store or extend a bytearray, instead of having to deal with malloc/free and and the mess that comes with it. Python takes care of the reference counts for bytearrays, and ctypes calls the

Re: [Numpy-discussion] NumPy re-factoring project

2010-06-10 Thread David Cournapeau
On Fri, Jun 11, 2010 at 6:56 AM, Sturla Molden stu...@molden.no wrote: Also about array iterators in NumPy's C base (i.e. for doing something along an axis): we don't need those. There is a different way of coding which leads to faster code. 1. Collect an array of pointers to each subarray

Re: [Numpy-discussion] [Job] research developer job opening at AQR Capital

2010-06-10 Thread Pierre GM
Wes, Sorry to contact you directly. I answered to this ad on 05/24, sending a cover letter and a link to my resume to Matt. However, I didn't get any news since. Do you mind telling me how to check the status of my application ? If it is rejected, so it goes, but I'd still like to know. In

[Numpy-discussion] timeseries - dates prior to 1970

2010-06-10 Thread Bevan Jenkins
Hello, I have posted previously about dates prior to 1900 but this seems to be a seperate issue. The error message is definitley different. I can not seem to convert a timseseries from one frequency ('D') to another ('H') when i use dates prior to 1970 as shown below. This works fine when I

Re: [Numpy-discussion] NumPy re-factoring project

2010-06-10 Thread Travis Oliphant
On Jun 10, 2010, at 11:48 AM, Sturla Molden wrote: I have a few radical suggestions: There are some good ideas there. I suspect we can't address all of them in the course of this re-factoring effort, but I really appreciate you putting them out there, because they are useful things to

Re: [Numpy-discussion] NumPy re-factoring project

2010-06-10 Thread Sturla Molden
Den 10.06.2010 22:28, skrev Pauli Virtanen: Some places where Openmp could probably help are in the inner ufunc loops. However, improving the memory efficiency of the data access pattern is another low-hanging fruit for multidimensional arrays. Getting the intermediate array out of

Re: [Numpy-discussion] NumPy re-factoring project

2010-06-10 Thread Pauli Virtanen
Thu, 10 Jun 2010 18:48:04 +0200, Sturla Molden wrote: [clip] 5. Allow OpenMP pragmas in the core. If arrays are above a certain size, it should switch to multi-threading. Some places where Openmp could probably help are in the inner ufunc loops. However, improving the memory efficiency of the

Re: [Numpy-discussion] NumPy re-factoring project

2010-06-10 Thread David Cournapeau
On Fri, Jun 11, 2010 at 7:25 AM, Sturla Molden stu...@molden.no wrote: Den 10.06.2010 22:07, skrev Travis Oliphant: 2. The core should be a plain DLL, loadable with ctypes. (I know David Cournapeau and Robert Kern is going to hate this.) But if Python can have a custom loader for .pyd

Re: [Numpy-discussion] NumPy re-factoring project

2010-06-10 Thread Sturla Molden
Den 10.06.2010 22:07, skrev Travis Oliphant: 2. The core should be a plain DLL, loadable with ctypes. (I know David Cournapeau and Robert Kern is going to hate this.) But if Python can have a custom loader for .pyd files, so can NumPy for it's core DLL. For ctypes we just need to specify a

Re: [Numpy-discussion] [Job] research developer job opening at AQR Capital

2010-06-10 Thread Pierre GM
Oops, somebody should double check who's in copy before sending his emails... Sorry about the noise all. However, feel free to contact me offlist w/ your ideas regarding handling time series in numpy. All my apologies again. P. ___ NumPy-Discussion

Re: [Numpy-discussion] NumPy re-factoring project

2010-06-10 Thread Sturla Molden
Den 11.06.2010 00:57, skrev David Cournapeau: Do you have the code for this ? That's something I wanted to do, but never took the time to do. Faster generic iterator would be nice, but very hard to do in general. /* this computes the start adress for every vector along a dimension (axis)

Re: [Numpy-discussion] NumPy re-factoring project

2010-06-10 Thread Charles R Harris
On Thu, Jun 10, 2010 at 6:27 PM, Sturla Molden stu...@molden.no wrote: Den 11.06.2010 00:57, skrev David Cournapeau: Do you have the code for this ? That's something I wanted to do, but never took the time to do. Faster generic iterator would be nice, but very hard to do in general.

Re: [Numpy-discussion] NumPy re-factoring project

2010-06-10 Thread David
On 06/11/2010 10:02 AM, Charles R Harris wrote: But for an initial refactoring it probably falls in the category of premature optimization. Another thing to avoid on the first go around is micro-optimization, as it tends to complicate the code and often doesn't do much for performance. I

Re: [Numpy-discussion] NumPy re-factoring project

2010-06-10 Thread David
On 06/11/2010 09:27 AM, Sturla Molden wrote: Strided memory access is slow. So it often helps to make a temporary copy that are contiguous. Ah, ok, I did not know this was called copy-in/copy-out, thanks for the explanation. I agree this would be a good direction to pursue, but maybe out of

Re: [Numpy-discussion] NumPy re-factoring project

2010-06-10 Thread Sturla Molden
Den 11.06.2010 04:19, skrev David: Ah, ok, I did not know this was called copy-in/copy-out, thanks for the explanation. I agree this would be a good direction to pursue, but maybe out of scope for the first refactoring, Copy-in copy-out is actually an implementation detail in Fortran

Re: [Numpy-discussion] timeseries - dates prior to 1970

2010-06-10 Thread Pierre GM
On Jun 10, 2010, at 7:16 PM, Bevan Jenkins wrote: Hello, I have posted previously about dates prior to 1900 but this seems to be a seperate issue. The error message is definitley different. I can not seem to convert a timseseries from one frequency ('D') to another ('H') when i use dates

Re: [Numpy-discussion] NumPy re-factoring project

2010-06-10 Thread Sturla Molden
Den 11.06.2010 03:02, skrev Charles R Harris: But for an initial refactoring it probably falls in the category of premature optimization. Another thing to avoid on the first go around is micro-optimization, as it tends to complicate the code and often doesn't do much for performance.

Re: [Numpy-discussion] NumPy re-factoring project

2010-06-10 Thread Charles R Harris
On Thu, Jun 10, 2010 at 8:40 PM, Sturla Molden stu...@molden.no wrote: Den 11.06.2010 03:02, skrev Charles R Harris: But for an initial refactoring it probably falls in the category of premature optimization. Another thing to avoid on the first go around is micro-optimization, as it