So many cool coding tricks from course 《Deep Learning》of Andrew Ng

Coding Tricks from Ng

# initialize the parameters of logistic regression

def initialize_with_zeros(dim):
    """
    This function creates a vector of zeros of shape (dim, 1) for w and initializes b to 0.
    
    Argument:
    dim -- size of the w vector we want (or number of parameters in this case)
    
    Returns:
    w -- initialized vector of shape (dim, 1)
    b -- initialized scalar (corresponds to the bias)
    """
    
    ### START CODE HERE ### (≈ 1 line of code)
    w = None
    b = None
    ### END CODE HERE ###

    assert(w.shape == (dim, 1))
    assert(isinstance(b, float) or isinstance(b, int))
    
    return w, b

assert(dw.shape == w.shape)
assert(db.dtype == float)

归一化的代码：

x -= np.mean(x, axis=0)

x /= np.std(x,axis=0)