[Numpy-discussion] Memory efficient equality test for arrays

2007-08-01 Thread Tom Goddard
Is there a numpy call to test if two large arrays (say 1 Gbyte each) are equal (same shape and elements) without creating another large array of booleans as happens with "a == b", numpy.equal(a,b), or numpy.array_equal(a,b)? I want a memory efficient and fast comparison. Tom _

Re: [Numpy-discussion] fourier with single precision

2007-08-01 Thread David Cournapeau
Lars Friedrich wrote: > Hello, > > is there a way to tell numpy.fft.fft2 to use complex64 instead of > complex128 as output dtype to speed the up transformation? > As far as I can read from the fft code in numpy, only double is supported at the moment, unfortunately. Note that you can get some

Re: [Numpy-discussion] How to implement a 'pivot table?'

2007-08-01 Thread Travis Vaught
Greetings, Speaking of brute force... I've attached a rather ugly module that let's you do things with a pretty simple interface (session shown below). I haven't fully tested the performance, but a million records with 5 fields takes about 11 seconds on my Mac to do a 'mean'. I'm not su

[Numpy-discussion] f2py self documenting not working

2007-08-01 Thread Randy Direen
Im using f2py under numpy. I've written several simple examples and f2py has not generated any documentations for the routines I have made. Any help would be great, I am very new to f2py and I would like to use the tool to wrap a rather large program written in Fortran90. Thanks! Randy Direen

Re: [Numpy-discussion] How to implement a 'pivot table?'

2007-08-01 Thread Bruce Southey
Hi, The hard part is knowing what aggregate function that you want. So a hard way, even after cheating, to take the data provided is given below. (The Numpy Example List was very useful especially on the where function)! I tried to be a little generic so you can replace the sum by any suitable fun

Re: [Numpy-discussion] reading 10 bit raw data into an array

2007-08-01 Thread Danny Chan
> > Quick comment : are you really sure your camera produces the 12 bit > data in a "12 bit stream" --- all I have ever seen is that cameras > would just use 16 bit for each pixel. (All you had to know if it uses > the left or the right part of those. In other words, you might have > to divide

Re: [Numpy-discussion] How to implement a 'pivot table?'

2007-08-01 Thread Vincent
I do a lot of this kind of things in SAS. In don't like SAS that much so it would be great to have functionality like this for numpy recarray's. To transplant the approach that SAS takes to a numpy setting you'd have something like the following 4 steps: 1. Sort the data by date and region 2. Dete

[Numpy-discussion] fourier with single precision

2007-08-01 Thread Lars Friedrich
Hello, is there a way to tell numpy.fft.fft2 to use complex64 instead of complex128 as output dtype to speed the up transformation? Thanks Lars ___ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/nump

Re: [Numpy-discussion] reading 10 bit raw data into an array

2007-08-01 Thread Sebastian Haase
On 8/1/07, Danny Chan <[EMAIL PROTECTED]> wrote: > Hi Travis! > I guess I will still have to pad my data to full bytes before reading it, > correct? > > Travis Oliphant <[EMAIL PROTECTED]> schrieb: > Danny Chan wrote: > > Hi all! > > I'm trying to read a data file that contains a raw image file. Ev

Re: [Numpy-discussion] reading 10 bit raw data into an array

2007-08-01 Thread Danny Chan
Hi Travis! I guess I will still have to pad my data to full bytes before reading it, correct? Travis Oliphant <[EMAIL PROTECTED]> schrieb: Danny Chan wrote: > Hi all! > I'm trying to read a data file that contains a raw image file. Every > pixel is assigned a value from 0 to 1023, and all pixels