Re: [Numpy-discussion] Apparently non-deterministic behaviour of complex array multiplication

2011-12-07 Thread Olivier Delalleau
I was trying to see if I could reproduce this problem, but your code fails with numpy 1.6.1 with: AttributeError: 'numpy.ndarray' object has no attribute 'H' Is X supposed to be a regular ndarray with dtype = 'complex128', or something else? -=- Olivier 2011/12/5 kneil magnetotellur...@gmail.com

Re: [Numpy-discussion] Apparently non-deterministic behaviour of complex array multiplication

2011-12-06 Thread kneil
Hi Nathaniel, The results of running memtest was a pass with no errors. -Karl Nathaniel Smith wrote: (You should still run memtest. It's very easy - just install it with your package manager, then reboot. Hold down the shift key while booting, and you'll get a boot menu. Choose memtest,

Re: [Numpy-discussion] Apparently non-deterministic behaviour of complex array multiplication

2011-12-05 Thread kneil
Hi Nathaniel, Thanks for the suggestion. I more or less implemented it: np.save('X',X); X2=np.load('X.npy') X2=np.asmatrix(X2) diffy = (X != X2) if diffy.any(): print X[diffy] print X2[diffy] print

Re: [Numpy-discussion] Apparently non-deterministic behaviour of complex array multiplication

2011-12-02 Thread kneil
OK - here is the status update on this problem: 1. To test for bad RAM, I saved the code plus data onto a usb drive and manually transferred it to a colleague's desktop machine with same specs as mine. The NaN values continued to appear at random, so it is unlikely to be bad RAM - unless its

Re: [Numpy-discussion] Apparently non-deterministic behaviour of complex array multiplication

2011-12-02 Thread Nathaniel Smith
If save/load actually makes a reliable difference, then it would be useful to do something like this, and see what you see: save(X, X) X2 = load(X.npy) diff = (X == X2) # did save/load change anything? any(diff) # if so, then what changed? X[diff] X2[diff] # any subtle differences in floating

Re: [Numpy-discussion] Apparently non-deterministic behaviour of complex array multiplication

2011-12-01 Thread Pierre Haessig
Le 01/12/2011 02:44, Karl Kappler a écrit : Also note that I have had a similar problem with much smaller arrays, say 24 x 3076 Hi Karl, Could you post a self-contained code with such a small array (or even smaller. the smaller, the better...) so that we can run it and play with it ? --

Re: [Numpy-discussion] Apparently non-deterministic behaviour of complex array multiplication

2011-12-01 Thread kneil
Hi Oliver, indeed that was a typo, I should have used cut and paste. I was using .transpose() Olivier Delalleau-2 wrote: I guess it's just a typo on your part, but just to make sure, you are using .transpose(), not .transpose, correct? -=- Olivier 2011/11/30 Karl Kappler

Re: [Numpy-discussion] Apparently non-deterministic behaviour of complex array multiplication

2011-12-01 Thread kneil
Hi Pierre, I was thinking about uploading some examples but strangely, when I store the array using for example: np.save('Y',Y) and then reload it in a new workspace, I find that the problem does not reproduce. It would seem somehow to be associated with the 'overhead' of the workspace I am

Re: [Numpy-discussion] Apparently non-deterministic behaviour of complex array multiplication

2011-12-01 Thread Joe Kington
On Thu, Dec 1, 2011 at 2:47 PM, kneil magnetotellur...@gmail.com wrote: Hi Pierre, I was thinking about uploading some examples but strangely, when I store the array using for example: np.save('Y',Y) and then reload it in a new workspace, I find that the problem does not reproduce. It

Re: [Numpy-discussion] Apparently non-deterministic behaviour of complex array multiplication

2011-12-01 Thread kneil
Hi Pierre, I confirmed with the guy who put together the machine that it is non-ECC RAM. You know, now that i think about it, this machine seems to crash a fair amount more often than its identical twin which sits on a desk near me. I researched memtest a bit... downloaded and compiled it, but

[Numpy-discussion] Apparently non-deterministic behaviour of complex array multiplication

2011-11-30 Thread Karl Kappler
Hello, I am somewhat new to scipy/numpy so please point me in the right direction if I am posting to an incorrect forum. The experience which has prompted my post is the following: I have a numpy array Y where the elements of Y are type(Y[0,0]) Out[709]: type 'numpy.complex128' The absolute

Re: [Numpy-discussion] Apparently non-deterministic behaviour of complex array multiplication

2011-11-30 Thread Olivier Delalleau
I guess it's just a typo on your part, but just to make sure, you are using .transpose(), not .transpose, correct? -=- Olivier 2011/11/30 Karl Kappler magnetotellur...@gmail.com Hello, I am somewhat new to scipy/numpy so please point me in the right direction if I am posting to an incorrect