Re: [Numpy-discussion] lazy loading ndarrays

2011-07-26 Thread Nadav Horesh
For lazy data loading I use memory-mapped array (numpy.memmap): I use it to process multi-image files that are much larger than the available RAM. Nadav. From: numpy-discussion-boun...@scipy.org [numpy-discussion-boun...@scipy.org] On Behalf Of Craig Yoshioka

Re: [Numpy-discussion] lazy loading ndarrays

2011-07-26 Thread Craig Yoshioka
ok, that was an alternative strategy I was going to try... but not my favorite as I'd have to explicitly perform all operations on the data portion of the object, and given numpy's mechanics, assignment would also have to be explicit, and creating new image objects implicitly would be trickier:

Re: [Numpy-discussion] lazy loading ndarrays

2011-07-26 Thread Joe Kington
Similar to what Matthew said, I often find that it's cleaner to make a seperate class with a "data" (or somesuch) property that lazily loads the numpy array. For example, something like: class DataFormat(object): def __init__(self, filename): self.filename = filename for key,

Re: [Numpy-discussion] lazy loading ndarrays

2011-07-26 Thread Matthew Brett
Hi, On Tue, Jul 26, 2011 at 5:11 PM, Craig Yoshioka wrote: > I want to subclass ndarray to create a class for image and volume data, and > when referencing a file I'd like to have it load the data only when accessed. >  That way the class can be used to quickly set and manipulate header values,

[Numpy-discussion] lazy loading ndarrays

2011-07-26 Thread Craig Yoshioka
I want to subclass ndarray to create a class for image and volume data, and when referencing a file I'd like to have it load the data only when accessed. That way the class can be used to quickly set and manipulate header values, and won't load data unless necessary. What is the best way to do

Re: [Numpy-discussion] code review/build & test for datetime business day API

2011-07-26 Thread Stéfan van der Walt
On Mon, Jul 25, 2011 at 2:29 PM, Charles R Harris wrote: >> Why?  Users can simply do >> >> import numpy.io as npyio ? >> > > It caused problems with 2to3 for one thing because it was getting imported > as io in the package. It is just a bad idea to shadow python modules and > best avoided. Call

Re: [Numpy-discussion] Problems with numpy binary for Python2.7 + OS X 10.6

2011-07-26 Thread Christopher Barker
On 7/25/11 1:00 PM, Ian Stokes-Rees wrote: > As best I can tell, I have Python 2.7.2 for my system Python: > > [ijstokes@moose ~]$ python -V > Python 2.7.2 > > [ijstokes@moose ~]$ which python > /Library/Frameworks/Python.framework/Versions/2.7/bin/python yup -- that is probably the python.org pyt

[Numpy-discussion] Multi-taper spectral analysis package: pymutt. Critical update.

2011-07-26 Thread martin smith
The current release, version 0.82.0, contains fixes for two major bugs. The first bug is a show-stopping segmentation fault under some versions of Linux and arises from a variable type mismatch in calls to the numpy api. The second bug causes bad spectral values at the Nyquist frequency for serie