+
−Objective Questions
+
−-------------------
+
−
+
− 1. What does ones_like([1, 2, 3]) produce
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−
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−   a. array([1, 1, 1])
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−   #. [1, 1, 1]
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−   #. [1.0, 1.0, 1.0]
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−   #. Error
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−   
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−   Answer: array([1, 1, 1])
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−   
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− 2. What does ones_like([1.2, 3, 4, 5]) produce
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−
+
−   a. [1.2, 3, 4, 5]
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−   #. array([1.0, 1.0, 1.0, 1.0])
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−   #. array([1, 1, 1, 1])
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−   #. array([1.2, 3, 4, 5])
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−
+
−   Answer: array([1.0, 1.0, 1.0, 1.0])
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−
+
− 3. The plot of ``u`` vs ``v`` is a bunch of scattered points that show a
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−    linear trend. How do you find the least square fit line of ``u`` vs ``v``.
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−
+
−   Answer::
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−
+
−      A = array(u, ones_like(u)).T
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−      result = lstsq(A, v)
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−      m, c = result[0]
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−
+
−      lst_line = m * u + c
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−