python: could not broadcast input array from shape (3,1) into shape (3,)
Question: 
    import numpy as np
    def qrhouse(A):
        (m,n) = A.shape
        R = A
        V = np.zeros((m,n))
        for k in range(0,min(m-1,n)):
            x = R[k:m,k]
            x.shape = (m-k,1)
            v = x + np.sin(x[0])*np.linalg.norm(x.T)*np.eye(m-k,1)
            V[k:m,k] = v
            R[k:m,k:n] = R[k:m,k:n]-(2*v)*(np.transpose(v)*R[k:m,k:n])/(np.transpose(v)*v)
        R = np.triu(R[0:n,0:n])     
        return V, R
    
    A = np.array( [[1,1,2],[4,3,1],[1,6,6]] )
    print qrhouse(A) 
    

It's qr factorization pytho code I don't know why error happens... value error
happens in `V[k:m,k] = v`

    
    
    value error :
    could not broadcast input array from shape (3,1) into shape (3) 
    

.


Answer: `V[k:m,k] = v`; `v` has shape (3,1), but the target is (3,). `k:m` is a 3 term
slice; `k` is a scalar.

Try using `v.ravel()`. Or `V[k:m,[k]]`.

But also understand why `v` has its shape.

