1 Objective Questions

     2 -------------------

     3 

     4  1. What does ones_like([1, 2, 3]) produce

     5 

     6    a. array([1, 1, 1])

     7    #. [1, 1, 1]

     8    #. [1.0, 1.0, 1.0]

     9    #. Error

    10    

    11    Answer: array([1, 1, 1])

    12    

    13  2. What does ones_like([1.2, 3, 4, 5]) produce

    14 

    15    a. [1.2, 3, 4, 5]

    16    #. array([1.0, 1.0, 1.0, 1.0])

    17    #. array([1, 1, 1, 1])

    18    #. array([1.2, 3, 4, 5])

    19 

    20    Answer: array([1.0, 1.0, 1.0, 1.0])

    21 

    22  3. The plot of ``u`` vs ``v`` is a bunch of scattered points that show a

    23     linear trend. How do you find the least square fit line of ``u`` vs ``v``.

    24 

    25    Answer::

    26 

    27       A = array(u, ones_like(u)).T

    28       result = lstsq(A, v)

    29       m, c = result[0]

    30 

    31       lst_line = m * u + c

    32