一、用法:zeros(shape, dtype=float, order=‘C’)
返回:返回来一个给定形状和类型的用0填充的数组;
二、参数:
1.shape:形状
2.dtype:数据类型,可选参数,默认numpy.float64
dtype类型:
-
t ,位域,如t4代表4位
-
b,布尔值,true or false
-
i,整数,如i8(64位)
-
u,无符号整数,u8(64位)
-
f,浮点数,f8(64位)
-
c,浮点负数,
-
o,对象,
-
s,a,字符串,s24
-
u,unicode,u24
3.order:可选参数,c代表与c语言类似,行优先;F代表列优
三、例子:
- 1.生成包含5个元素的零矩阵
np.zeros(5)
array([ 0., 0., 0., 0., 0.])
- 2.生成包含5个元素的零矩阵,且各元素为整形
np.zeros((5,), dtype=np.int)
array([0, 0, 0, 0, 0])
- 3.生成2行1列的零矩阵
np.zeros((2, 1))
array([[ 0.],[ 0.]])
- 4.生成2行2列的零矩阵
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.]])
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’)])
Type: builtin_function_or_method