Re: [Numpy-discussion] How to limit cross correlation window width in Numpy?

2015-06-21 Thread Mansour Moufid
I just realized that NumPy uses the time domain algorithm for correlation. So it would be much easier to modify the correlation functions in SciPy than in NumPy. ___ NumPy-Discussion mailing list NumPy-Discussion@scipy.org

Re: [Numpy-discussion] How to limit cross correlation window width in Numpy?

2015-06-21 Thread Honi Sanders
Did you check out my implementation? I was able to modify the Numpy correlate function just fine. https://github.com/numpy/numpy/compare/master...bringingheavendown:maxlag On Jun 21, 2015, at 1:53 PM, Mansour Moufid mansourmou...@gmail.com wrote: I just realized that NumPy uses the time

Re: [Numpy-discussion] How to limit cross correlation window width in Numpy?

2015-06-18 Thread Sturla Molden
Mansour Moufid mansourmou...@gmail.com wrote: The cross-correlation of two arrays of lengths m and n is of length m + n - 1, where m is usually much larger than n. He is thinking about the situation where m == n and m is much larger than maxlag. Truncating the input arrays would also throw

Re: [Numpy-discussion] How to limit cross correlation window width in Numpy?

2015-06-17 Thread Sturla Molden
On 17/06/15 04:38, Honi Sanders wrote: I have now implemented this functionality in numpy.correlate() and numpy.convolve(). https://github.com/bringingheavendown/numpy. The files that were edited are: numpy/core/src/multiarray/multiarraymodule.c numpy/core/numeric.py

Re: [Numpy-discussion] How to limit cross correlation window width in Numpy?

2015-06-17 Thread Honi Sanders
I will also repeat what I said in response on Github (discussions at: https://github.com/scipy/scipy/issues/4940, https://github.com/numpy/numpy/issues/5954): I do want a function that computes cross-correlograms, however the implementation is exactly the same for cross-correlograms as

Re: [Numpy-discussion] How to limit cross correlation window width in Numpy?

2015-06-17 Thread Mansour Moufid
Hello, There is a simple solution. The cross-correlation of two arrays of lengths m and n is of length m + n - 1, where m is usually much larger than n. If you need to compute the cross-correlation with a bound on the lag of k, then truncate the longer array to length k - n + 1. That is, def

Re: [Numpy-discussion] How to limit cross correlation window width in Numpy?

2015-06-16 Thread Honi Sanders
I have now implemented this functionality in numpy.correlate() and numpy.convolve(). https://github.com/bringingheavendown/numpy. The files that were edited are: numpy/core/src/multiarray/multiarraymodule.c numpy/core/numeric.py numpy/core/tests/test_numeric.py Please look over the code, my

[Numpy-discussion] How to limit cross correlation window width in Numpy?

2015-06-08 Thread Honi Sanders
I am learning numpy/scipy, coming from a MATLAB background. The xcorr function in Matlab has an optional argument maxlag that limits the lag range from –maxlag to maxlag. This is very useful if you are looking at the cross-correlation between two very long time series but are only interested in