Re: [Numpy-discussion] numpy.mean still broken for largefloat32arrays

2014-07-28 Thread Julian Taylor
On 28.07.2014 23:32, Eelco Hoogendoorn wrote: > I see, thanks for the clarification. Just for the sake of argument, > since unfortunately I don't have the time to go dig in the guts of numpy > myself: a design which always produces results of the same (high) > accuracy, but only optimizes the commo

Re: [Numpy-discussion] numpy.mean still broken for largefloat32arrays

2014-07-28 Thread Eelco Hoogendoorn
I see, thanks for the clarification. Just for the sake of argument, since unfortunately I don't have the time to go dig in the guts of numpy myself: a design which always produces results of the same (high) accuracy, but only optimizes the common access patterns in a hacky way, and may be inefficie

Re: [Numpy-discussion] numpy.mean still broken for largefloat32arrays

2014-07-28 Thread Sebastian Berg
On Mo, 2014-07-28 at 16:31 +0200, Eelco Hoogendoorn wrote: > Sebastian: > > > Those are good points. Indeed iteration order may already produce > different results, even though the semantics of numpy suggest > identical operations. Still, I feel this different behavior without > any semantical cl

Re: [Numpy-discussion] 64-bit windows numpy / scipy wheels for testing

2014-07-28 Thread Carl Kleffner
I had to move my development enviroment on different windows box recently (stilll in progress). On this box I don't have full access unfortunately. The patch for scipy build was merged into scipy master some time ago, see https://github.com/scipy/scipy/pull/3484 . I have some additional patches for

Re: [Numpy-discussion] 64-bit windows numpy / scipy wheels for testing

2014-07-28 Thread Olivier Grisel
2014-07-28 15:25 GMT+02:00 Carl Kleffner : > Hi, > > on https://bitbucket.org/carlkl/mingw-w64-for-python/downloads I uploaded > 7z-archives for mingw-w64 and for OpenBLAS-0.2.10 for 32 bit and for 64 bit. > To use mingw-w64 for Python >= 3.3 you have to manually tweak the so called > specs file -

Re: [Numpy-discussion] numpy.mean still broken for largefloat32arrays

2014-07-28 Thread Eelco Hoogendoorn
Sebastian: Those are good points. Indeed iteration order may already produce different results, even though the semantics of numpy suggest identical operations. Still, I feel this different behavior without any semantical clues is something to be minimized. Indeed copying might have large speed i

Re: [Numpy-discussion] numpy.mean still broken for largefloat32arrays

2014-07-28 Thread Sebastian Berg
On Mo, 2014-07-28 at 15:50 +0200, Fabien wrote: > On 28.07.2014 15:30, Daπid wrote: > > An example using float16 on Numpy 1.8.1 (I haven't seen diferences with > > float32): > > Why aren't there differences between float16 and float32 ? > float16 calculations are actually float32 calculations. I

Re: [Numpy-discussion] numpy.mean still broken for largefloat32arrays

2014-07-28 Thread Sebastian Berg
On Mo, 2014-07-28 at 15:35 +0200, Sturla Molden wrote: > On 28/07/14 15:21, alex wrote: > > > Are you sure they always give different results? Notice that > > np.ones((N,2)).mean(0) > > np.ones((2,N)).mean(1) > > compute means of different axes on transposed arrays so these > > differences 'cance

Re: [Numpy-discussion] numpy.mean still broken for largefloat32arrays

2014-07-28 Thread Fabien
On 28.07.2014 15:30, Daπid wrote: > An example using float16 on Numpy 1.8.1 (I haven't seen diferences with > float32): Why aren't there differences between float16 and float32 ? Could this be related to my earlier post in this thread where I mentioned summation problems occurring much earlier i

Re: [Numpy-discussion] numpy.mean still broken for largefloat32arrays

2014-07-28 Thread Sturla Molden
On 28/07/14 15:21, alex wrote: > Are you sure they always give different results? Notice that > np.ones((N,2)).mean(0) > np.ones((2,N)).mean(1) > compute means of different axes on transposed arrays so these > differences 'cancel out'. They will be if different algorithms are used. np.ones((N,2)

Re: [Numpy-discussion] numpy.mean still broken for largefloat32arrays

2014-07-28 Thread Daπid
On 28 July 2014 14:46, Sebastian Berg wrote: > > To rephrase my most pressing question: may np.ones((N,2)).mean(0) and > > np.ones((2,N)).mean(1) produce different results with the > > implementation in the current master? If so, I think that would be > > very much regrettable; and if this is a m

Re: [Numpy-discussion] 64-bit windows numpy / scipy wheels for testing

2014-07-28 Thread Carl Kleffner
Hi, on https://bitbucket.org/carlkl/mingw-w64-for-python/downloads I uploaded 7z-archives for mingw-w64 and for OpenBLAS-0.2.10 for 32 bit and for 64 bit. To use mingw-w64 for Python >= 3.3 you have to manually tweak the so called specs file - see readme.txt in the archive. Regards Carl 2014-

Re: [Numpy-discussion] numpy.mean still broken for largefloat32arrays

2014-07-28 Thread alex
On Mon, Jul 28, 2014 at 8:46 AM, Sebastian Berg wrote: > On Mo, 2014-07-28 at 14:37 +0200, Eelco Hoogendoorn wrote: >> To rephrase my most pressing question: may np.ones((N,2)).mean(0) and >> np.ones((2,N)).mean(1) produce different results with the >> implementation in the current master? If so,

Re: [Numpy-discussion] numpy.mean still broken for largefloat32arrays

2014-07-28 Thread Sebastian Berg
On Mo, 2014-07-28 at 14:37 +0200, Eelco Hoogendoorn wrote: > To rephrase my most pressing question: may np.ones((N,2)).mean(0) and > np.ones((2,N)).mean(1) produce different results with the > implementation in the current master? If so, I think that would be > very much regrettable; and if this is

Re: [Numpy-discussion] numpy.mean still broken for largefloat32arrays

2014-07-28 Thread Eelco Hoogendoorn
To rephrase my most pressing question: may np.ones((N,2)).mean(0) and np.ones((2,N)).mean(1) produce different results with the implementation in the current master? If so, I think that would be very much regrettable; and if this is a minority opinion, I do hope that at least this gets documented i