如何编写向量函数来应用操作 f(x,y)？

Question

scalar_function can only handle scalar input, we could use the function np.vectorize() turn it into a vectorized function. Note that the input argument of np.vectorize() should be a scalar function, and the output of np.vectorize() is a new function that can handle vector input.

Please write a vector function vector_function, which will apply the operation 𝑓(𝑥,𝑦) defined above element-wisely with input vectors with same dimension x and y.

So for the scalar, I got :

def scalar_function(x, y):
    
    if x <= y:
        return x*y
    else:
        return x/y

For the vector function I have :

def vector_function(x, y):

    vfunc = np.vectorize(scalar_function, otypes = [float])
    return vfunc

From here on I am stuck.

Answer 1

尝试这个

vector_function = np.vectorize(scalar_function)

Answer 2

based on this 'Please write a vector function vector_function, which will apply the operation 𝑓(𝑥,𝑦) defined above element-wisely with input vectors with same dimension x and y' here is what you are looking for:

import numpy as np
def scalar_function(x, y):
    if x <= y:
        return x*y
    else:
        return x/y

vector_function = np.vectorize(scalar_function, otypes = [float])

print(vector_function(np.array([1, 2, 3, 6]), np.array([1, 3, 4, 5])))
[Output]>>> [ 1.   6.  12.   1.2]