python中numpy.zeros(np.zeros)的使用方法
阿新 • • 發佈:2018-11-04
用法:zeros(shape, dtype=float, order='C')
返回:返回來一個給定形狀和型別的用0填充的陣列;
引數:shape:形狀
dtype:資料型別,可選引數,預設numpy.float64
dtype型別:
t ,位域,如t4代表4位
b,布林值,true or false
i,整數,如i8(64位)
u,無符號整數,u8(64位)
f,浮點數,f8(64位)
c,浮點負數,
o,物件,
s,a,字串,s24
u,unicode,u24
order:可選引數,c代表與c語言類似,行優先;F代表列優先
例子:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 |
np.zeros(5)
array([ 0., 0., 0., 0., 0.])
np.zeros((5,), dtype=np.int)
array([0, 0, 0, 0, 0])
np.zeros((2, 1)) array([[ 0.],
[ 0.]])
s = (2,2)
np.zeros(s)
array([[ 0., 0.],
[ 0., 0.]])
np.zeros((2,), dtype=[('x', 'i4'), ('y', 'i4')]) # custom dtype
array([(0, 0), (0, 0)],
dtype=[('x', '<i4'), ('y', '<i4')])
########################################################
zeros(shape, dtype=float, order='C')
Return a new array of given shape and type, filled with zeros.
Parameters
----------
shape : int or sequence of ints
Shape of the new array, e.g., ``(2, 3)`` or ``2``.
dtype : data-type, optional
The desired data-type for the array, e.g., `numpy.int8`. Default is
`numpy.float64`.
order : {'C', 'F'}, optional
Whether to store multidimensional data in C- or Fortran-contiguous
(row- or column-wise) order in memory.
Returns
-------
out : ndarray
Array of zeros with the given shape, dtype, and order.
See Also
--------
zeros_like : Return an array of zeros with shape and type of input.
ones_like : Return an array of ones with shape and type of input.
empty_like : Return an empty array with shape and type of input.
ones : Return a new array setting values to one.
empty : Return a new uninitialized array.
Examples
--------
np.zeros(5)
array([ 0., 0., 0., 0., 0.])
np.zeros((5,), dtype=np.int)
array([0, 0, 0, 0, 0])
np.zeros((2, 1))
array([[ 0.],
[ 0.]])
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