Example
Empty array
np.empty((2,3))
Note that in this case, the values in this array are not set. This way of creating an array is therefore only useful if the array is filled later in the code.
From a list
np.array([0,1,2,3])
# Out: array([0, 1, 2, 3])
Create a range
np.arange(4)
# Out: array([0, 1, 2, 3])
Create Zeros
np.zeros((3,2))
# Out:
# array([[ 0., 0.],
# [ 0., 0.],
# [ 0., 0.]])
Create Ones
np.ones((3,2))
# Out:
# array([[ 1., 1.],
# [ 1., 1.],
# [ 1., 1.]])
Create linear-spaced array items
np.linspace(0,1,21)
# Out:
# array([ 0. , 0.05, 0.1 , 0.15, 0.2 , 0.25, 0.3 , 0.35, 0.4 ,
# 0.45, 0.5 , 0.55, 0.6 , 0.65, 0.7 , 0.75, 0.8 , 0.85,
# 0.9 , 0.95, 1. ])
Create log-spaced array items
np.logspace(-2,2,5)
# Out:
# array([ 1.00000000e-02, 1.00000000e-01, 1.00000000e+00,
# 1.00000000e+01, 1.00000000e+02])
Create array from a given function
np.fromfunction(lambda i: i**2, (5,))
# Out:
# array([ 0., 1., 4., 9., 16.])
np.fromfunction(lambda i,j: i**2, (3,3))
# Out:
# array([[ 0., 0., 0.],
# [ 1., 1., 1.],
# [ 4., 4., 4.]])
