[Numpy-discussion] Excluding index in numpy like negative index in R?

Keith Goodman kwgoodman@gmail....
Tue Dec 9 15:07:08 CST 2008

On Tue, Dec 9, 2008 at 12:25 PM, Bab Tei <babaktei@yahoo.com> wrote:

> I can exclude a list of items by using negative index in R (R-project) ie myarray[-excludeindex]. As negative indexing in numpy (And python) behave differently ,how can I exclude a list of item in numpy?

Here's a painful way to do it:

>> x = np.array([0,1,2,3,4])
>> excludeindex = [1,3]
>> idx = list(set(range(4)) - set(excludeindex))
>> x[idx]
   array([0, 2])

To make it more painful, you might want to sort idx.

But if excludeindex is True/False, then just use ~excludeindex.

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