NumPy | logical_or method
logical_or(~) compares the input arrays element-wise, and for each comparison, returns True if either of the values evaluates to True.
The first input array.
The second input array.
Numpy array |
Instead of creating a new array, you can place the computed result into the array specified by
Values that are flagged as False will be ignored, that is, their original value will be uninitialized. If you specified the out parameter, the behavior is slightly different - the original value will be kept intact.
x2 are scalars, then a single boolean is returned. Otherwise, a Numpy array of booleans is returned.
np.logical_or([False, True], [False, True])array([False, True])
On a more practical note, suppose we wanted to find even numbers and numbers larger than 3 from an array:
a = np.array([1,2,3,4,5])mask = np.logical_or(a%2==0, a>3)maskarray([False, True, False, True, True])
To fetch the values that fit our criteria (i.e. the one flagged as True):
a[mask]aarray([2, 4, 5])