How to use numpy.where with logical operators
logical-operators, numpy, python, where-clause
Solution
Here are two ways:
In [1]: my_array = arange(10)
In [2]: where((my_array > 3) & (my_array < 7))
Out[2]: (array([4, 5, 6]),)
In [3]: where(logical_and(my_array > 3, my_array < 7))
Out[3]: (array([4, 5, 6]),)
For the first (replacing `and` with `&`), be careful to add parentheses appropriately: `&` has higher precedence than the comparison operators. You can also use `*`, but I wouldn't recommend it: it's hacky and doesn't make for readable code.
In [4]: where((my_array > 3) * (my_array < 7))
Out[4]: (array([4, 5, 6]),)
Problem
I'm trying to find the indices of all elements in an array that are greater than a but less than b. It's probably just a problem with my syntax but this doesn't work: ``` numpy.where((my_array > a) and (my_array < b)) ``` How should I fix this? Or is there a better way to do it? Thanks!