Selecting specific column in each row from array
numpy, python
Solution
You can use:
a[np.arange(3), (0,1,0)]
in your example above.
Problem
I am trying to select specific column elements for each row of a numpy array. For example, in the following example: ``` In [1]: a = np.random.random((3,2)) Out[1]: array([[ 0.75670668, 0.1283942 ], [ 0.51326555, 0.59378083], [ 0.03219789, 0.53612603]]) ``` I would like to select the first element of the first row, the second element of the second row, and the first element of the third row. So I tried to do the following: ``` In [2]: b = np.array([0,1,0]) In [3]: a[:,b] ``` But this produces the following output: ``` Out[3]: array([[ 0.75670668, 0.1283942 , 0.75670668], [ 0.51326555, 0.59378083, 0.51326555], [ 0.03219789, 0.53612603, 0.03219789]]) ``` which clearly is not what I am looking for. Is there an easy way to do what I would like to do without using loops?