python using smaller 2D array to map with another bigger array

Question

I have a smaller array as:

A = np.array([2013, 2014, 2015])
Aval = np.array([14, 10, 35])

I have another array:

A2 = np.array([2013, 2014, 2015, 2013, 2014, 2015, 2013, 2013, 2013])

I want to create A2val such that:

Arval = np.array([14, 10, 35, 14, 10, 35, 14, 14, 14])

so, I am trying to use the values in array A to map to elements of A2 and generate an extended version of A2val

Divakar · Accepted Answer · 2016-07-14 20:02:20Z

2

You can use np.searchsorted to create the mapping indices and then index into Aval for selecting elements off it, like so -

Aval[np.searchsorted(A,A2)]

If A is not already sorted, we need to use the optional argument sorter, like so -

Aval[np.searchsorted(A,A2,sorter=A.argsort())]

answered Jul 14, 2016 at 20:02

Divakar

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