Re: [Numpy-discussion] numpy.correlate with phase offset 1D data series

2008-03-04 Thread Ray Schumacher
At 03:28 PM 3/3/2008, Ann wrote: > >Sounds familiar. If you have a good signal-to-noise ratio, you can get > >subpixel accuracy by oversampling the irfft, or better but slower, by > >using numerical optimization to refine the peak you found with argmax. the S/N here is poor, and high data rates wo

Re: [Numpy-discussion] numpy.correlate with phase offset 1D data series

2008-03-04 Thread Ray Schumacher
Thank you for the input! It sounds like Fourier methods will be fastest, by design, for sample counts of hundreds to thousands. I currently do steps like: Im1 = get_stream_array_data() Im2 = load_template_array_data(fh2) ##note: len(im1)==len(im2) Ffft_im1=fftpack.rfft(Im1) Ffft_im2=fftpack.rfft(

[Numpy-discussion] numpy.correlate with phase offset 1D data series

2008-03-03 Thread Ray Schumacher
At 01:24 PM 3/3/2008, you wrote: > > If you use 'same' or 'full' you'll end of with different > >amounts of offset. I imagine that this is due to the way the data is padded. > >The offset should be deterministic based on the mode and the size of the > >data, so it should be straightforward to compe

[Numpy-discussion] numpy.correlate with phase offset 1D data series

2008-03-03 Thread Ray Schumacher
I'm trying to figure out what numpy.correlate does, and, what are people using to calculate the phase shift of 1D signals? (I coded on routine that uses rfft, conjugate, ratio, irfft, and argmax based on a paper by Hongjie Xie "An IDL/ENVI implementation of the FFT Based Algorithm for Automat

[Numpy-discussion] image to array doubt

2008-02-29 Thread Ray Schumacher
numpy array objects http://effbot.org/zone/pil-changes-116.htm frombuffer, fromstring, fromarray, tostring etc. http://www.pythonware.com/library/pil/handbook/image.htm (I've used them for home astronomy projects, myself.) Ray Schumacher Blue Cove Interactive No virus found in this outgoin

[Numpy-discussion] numpy Intel ICC build help?

2008-01-17 Thread Ray Schumacher
We've just built Python 2.4 in the lab with Intel ICC and MS VS 2005, but had problems building 2.5, and also numpy, with the MKL. Would someone be willing to share their build experience or project files? Ray -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7

[Numpy-discussion] Intel MKL - was: parallel numpy - any info?

2008-01-09 Thread Ray Schumacher
distros, and our company now has (finally) decided to purchase the ICC and MKL with the intention of compiling for P4 and Core2 targets. The binaries could then go up on the company's web site. Thanks, Ray Schumacher -- No virus found in this outgoing message. Checked by AVG Free Edition

Re: [Numpy-discussion] parallel numpy - any info?

2008-01-08 Thread Ray Schumacher
sourceforge.net/ seem like the ticket. Whatever happened to pyGA? GA http://www.emsl.pnl.gov/docs/global/ is still around. http://www.ece.lsu.edu/jxr/pohll-02/papers/jarek.pdf Best, Ray Schumacher -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.516 / Virus Da

Re: [Numpy-discussion] Changing the distributed binary for numpy 1.0.4 for windows ?

2007-12-11 Thread Ray Schumacher
r numpy - I had seen a poster who offered help. When the company actually purchases the product I'd be glad to do it on 2-3 targets if someone can assist with the parameters. We have one consultant here who has done it on Linux. Ray Schumacher Congitive Vision 8580 Production Ave.,

Re: [Numpy-discussion] numpy FFT memory accumulation

2007-11-02 Thread Ray Schumacher
At 10:57 PM 11/1/2007, Charles R Harris wrote: > > An additional complication is that I pass the numpy (or Numeric) > > array address to the ctypes library call so that the data is placed > > directly into the array from the call. I use the if/else end wrap > > logic to determine whether I need to

Re: [Numpy-discussion] numpy FFT memory accumulation

2007-11-01 Thread Ray Schumacher
At 11:55 PM 10/31/2007, Travis wrote: >Ray S wrote: > > I am using > > fftRes = abs(fft.rfft(data_array[end-2**15:end])) > > >At first glance, I would say that I don't expect memory to be growing >here, so it looks like a problem with rfft that deserves looking into. I saw that Numeric did also (I

Re: [Numpy-discussion] numpy/Windows shared arrays between processes?

2007-10-09 Thread Ray Schumacher
to create arrays from the other process's address and laying a numpy array on top was prone to that in experimentation. But I had the same issue as Mark Heslep http://aspn.activestate.com/ASPN/Mail/Message/ctypes-users/3192422 of creating a numpy array fro

Re: [Numpy-discussion] Compile extension modules with Visual Studio 2005

2007-07-25 Thread Ray Schumacher
Geoffrey Zhu wrote: > Hi, > > I am about to write a C extension module. C functions in the module will > take and return numpy arrays. I found a tutorial online, but I am not > sure about the following: I agree with others that ctypes might be your best path. The codeGenerator is magic, if yo

Re: [Numpy-discussion] numpy array sharing between processes?

2007-05-12 Thread Ray Schumacher
Andrew added: I'll pitch in a few donuts (and my eternal gratitude) for an example of shared memory use using numpy arrays that is cross platform, or at least  works in linux, mac, and windows. I thought that getting the address from the buffer() of the array and creating a new one from it in th

[Numpy-discussion] numpy array sharing between processes?

2007-05-12 Thread Ray Schumacher
After Googling for examples on this, in the Cookbook http://www.scipy.org/Cookbook/Multithreading MPI and POSH (dead?), I don't think I know the answer... We have a data collection app running on dual core processors; I start one thread collecting/writing new data directly into a numpy circular

Re: [Numpy-discussion] NumPy benchmark

2007-04-17 Thread Ray Schumacher
I'm still curious about the licensing aspects of using Intel's compiler and libs. Is the compiled Python/numpy result distributable, like any other compiled program? Ray ___ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scip

Re: [Numpy-discussion] building numpy with Intel MS compiler and FFT

2007-04-15 Thread Ray Schumacher
Thanks Rex, I'll give it a try next week. >I've compiled both Numpy and Python 2.5 with the Intel compiler. On a >Core 2 Duo, at least, the speed increase on Pybench was ~49%, even >before compiling Python with icc. My post about it was on 25 Jan, and >has subject: Compiling Python with icc _

[Numpy-discussion] building numpy with Intel MS compiler and FFT

2007-04-14 Thread Ray Schumacher
Has anyone built Python/numpy with the Intel optimized compiler and FFT lib for Microsoft, and have any pointers? We're counting on the extra speed, and will be getting the compiler and libraries next week. Is there a consensus on distribution requirements for Python compiled with the Intel co

Re: [Numpy-discussion] zoom FFT with numpy?

2007-03-14 Thread Ray Schumacher
On 3/14/07, "Charles R Harris" wrote: > Sounds like you want to save cpu cycles. > How much you can save will depend > on the ratio of the bandwidth to the nyquist. The desired band is rather narrow, as the goal is to determine the f of a peak that always occurs in a narrow band of about 1kHz