Numpy - check if elements of a array belong to another array
You can make use of numpy.in1d, the rest is pretty simple:
The key part:
In [25]: np.in1d(xarr, y)Out[25]: array([ True, True, False, False, False], dtype=bool)Whole example:
In [16]: result = np.empty(len(xarr), dtype=object)In [17]: resultOut[17]: array([None, None, None, None, None], dtype=object)In [18]: result.fill("n")In [19]: resultOut[19]: array(['n', 'n', 'n', 'n', 'n'], dtype=object)In [20]: result[np.in1d(xarr, y)] = 'y'In [21]: resultOut[21]: array(['y', 'y', 'n', 'n', 'n'], dtype=object)In [23]: result[xarr == 1.3] = 'y1'In [24]: resultOut[24]: array(['y', 'y', 'y1', 'n', 'n'], dtype=object)Edit:
A small modification of your original attempt:
In [16]: x = np.where(np.in1d(xarr, y),"y",np.where(xarr == 1.3,"y1","n"))In [17]: xOut[17]: array(['y', 'y', 'y1', 'n', 'n'], dtype='|S2')The problem in your original attempt was that xarr in y gives just False.