<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def point_stokes(self, context):
 """ Return a stokes parameter array to montblanc """

        stokes = np.empty(context.shape, context.dtype)
        stokes[:,:,0] = 1
        stokes[:,:,1:4] = 0
        return stokes