Try using slice (python builtin) to create slice objects (what is created implicitly by :5, 1:20, etc.). slice takes the same arguments as range. A list of these (7 in your case) can then be passed to A[...] as a tuple.
That's how I would do it, but maybe someone else has a better idea or can correct me. --Hoyt On Wed, Aug 6, 2008 at 4:02 PM, Matthew Czesarski <[EMAIL PROTECTED]> wrote: > Dear list. > > I've got a feeling that what I'm trying to do *should* be easy but at the > moment I can't find a non-brute-force method. > > I'm working with quite a high-rank matrix; 7 dimensions filled with chi**2 > values. It's form is something like this: > > chi2 = numpy.ones((3,4,5,6,7,8,9)) > > What I need to do is slice out certain 2 dimensional grids that I then want > to plot for confidence estimation; make a nice graph. This is fine: as easy > as it gets if the 2 dimensions are known. E.g. for the 2nd and 5th axes, one > could hardcode something like this: > > subChi2 = chi2[ ia, ib, :, id, ie, :, ig ] > > The difficulty is that the user is to state which plane (s)he wants to slice > out and we can't code the above. The function itself has to convert 2 rank > numbers into an expression for a slice and I can't currently figure out how > to do that. There are a huge number of options (well, there are 7*6=42). If > one could just manually write a colon into a tuple like (2,2,:,2,2,:,2) or > something even like 2,2,0:len(2ndDim),2,2,0:len(5thDim),2, things would be > fine. But that doesn't seem to be an option. An alternative would be to set > up 2 loops and incrementally read out the individual elements of the slice > to a new numpy.zeros ( ( len(2ndDim), len(5thDim) ) ), but again we seem to > be diverging from elegance. > > There must be something that I'm missing. Could somebody have a pointer as > to what it is? > > Thanks in advance, > Matt > > > _______________________________________________ > Numpy-discussion mailing list > Numpy-discussion@scipy.org > http://projects.scipy.org/mailman/listinfo/numpy-discussion > > -- +++++++++++++++++++++++++++++++++++ Hoyt Koepke UBC Department of Computer Science http://www.cs.ubc.ca/~hoytak/ [EMAIL PROTECTED] +++++++++++++++++++++++++++++++++++ _______________________________________________ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/numpy-discussion