A new ndarray object can be constructed by any of the following array creation routines or using a low-level ndarray constructor.
It creates an uninitialized array of specified shape and dtype. It uses the following constructor −
numpy.empty(shape, dtype = float, order = 'C')
Parameter | Description | |||
---|---|---|---|---|
Shape | Shape of an empty array in int or tuple of int | |||
Dtype | Desired output data type. Optional | |||
Order | 'C' for C-style row-major array, 'F' for FORTRAN style column-major array |
import numpy as np
x = np.empty([3,2], dtype = int)
print (x)
Returns a new array of specified size, filled with zeros.
numpy.zeros(shape, dtype = float, order = 'C')
Parameter | Description | |||
---|---|---|---|---|
Shape | Shape of an empty array in int or tuple of int | |||
Dtype | Desired output data type. Optional | |||
Order | 'C' for C-style row-major array, 'F' for FORTRAN style column-major array |
# array of five zeros. Default dtype is float
import numpy as np
x = np.zeros(5)
print (x)
import numpy as np
x = np.zeros((5,), dtype = np.int)
print (x)
# custom type
import numpy as np
x = np.zeros((2,2), dtype = [('x', 'i4'), ('y', 'i4')])
print (x)
Returns a new array of specified size and type, filled with ones.
numpy.ones(shape, dtype = None, order = 'C')
Parameter | Description | |||
---|---|---|---|---|
Shape | Shape of an empty array in int or tuple of int | |||
Dtype | Desired output data type. Optional | |||
Order | 'C' for C-style row-major array, 'F' for FORTRAN style column-major array |
# array of five ones. Default dtype is float
import numpy as np
x = np.ones(5)
print (x)
import numpy as np
x = np.ones([2,2], dtype = int)
print (x)