numpy零如何实现参数形状？

Question

我想实现一个类似的功能，并且想要接受一个数组或数字，我传递给numpy.ones。

具体来说，我想这样做：

def halfs(shape): 
    shape = numpy.concatenate([2], shape) 
    return 0.5 * numpy.ones(shape) 

例输入 - 输出对：

# default 
In [5]: beta_jeffreys() 
Out[5]: array([-0.5, -0.5]) 

# scalar 
In [5]: beta_jeffreys(3) 
Out[3]: 
array([[-0.5, -0.5, -0.5], 
     [-0.5, -0.5, -0.5]]) 

# vector (1) 
In [3]: beta_jeffreys((3,)) 
Out[3]: 
array([[-0.5, -0.5, -0.5], 
     [-0.5, -0.5, -0.5]]) 

# vector (2) 
In [7]: beta_jeffreys((2,3)) 
Out[7]: 
array([[[-0.5, -0.5, -0.5], 
     [-0.5, -0.5, -0.5]], 

     [[-0.5, -0.5, -0.5], 
     [-0.5, -0.5, -0.5]]]) 

Answer 1

def halfs(shape=()): 
    if isinstance(shape, tuple): 
     return 0.5 * numpy.ones((2,) + shape) 
    else: 
     return 0.5 * numpy.ones((2, shape)) 



a = numpy.arange(5) 
# array([0, 1, 2, 3, 4]) 


halfs(a.shape) 
#array([[ 0.5, 0.5, 0.5, 0.5, 0.5], 
#  [ 0.5, 0.5, 0.5, 0.5, 0.5]]) 

halfs(3) 
#array([[ 0.5, 0.5, 0.5], 
#  [ 0.5, 0.5, 0.5]])