MATLAB find function translate to python - 3 input arguments version

Question

In MATALAB I can write easily:

ind = find(X, k, 'last')

that returns at most the last k indices corresponding to the nonzero entries of X.

Numpy has the numpy.nonzero function just for the MATALAB find(X), the one parameter version.

Which is numpythonic way to translate find with 3 arguments?

Check out the Mathesaurus page. (The webpage is awesome and helped me go from Matlab to R). — Richard Erickson
– Richard Erickson, Commented May 7, 2015 at 1:27
The numpy find returns a tuple - one array for each dimension. Do the normal indexing on this tuple. — hpaulj
– hpaulj, Commented May 7, 2015 at 2:02

cosmoscalibur · Accepted Answer · 2015-05-07 01:47:43Z

2

Equivalent expression is

# importing numpy as np and
# assign a ndarray to x
ind = np.nonzero(x)[-k:]

Using slicing you replace the use of 'last' argument.

answered May 7, 2015 at 1:47

cosmoscalibur

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Comments

Jason Newton · Accepted Answer · 2015-05-07 01:52:26Z

1

You will need to apply the last or first k through array slicing of the result.

answered May 7, 2015 at 1:25

Jason Newton

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