st-scripts: lstsq/questions.rst@cb3974daced5 (annotated)

237 6c203780bfbe Converted lstsq to new template form Nishanth <nishanth@fossee.in> parents: diff changeset	1	Objective Questions
6c203780bfbe Converted lstsq to new template form Nishanth <nishanth@fossee.in> parents: diff changeset	2	-------------------
6c203780bfbe Converted lstsq to new template form Nishanth <nishanth@fossee.in> parents: diff changeset	3
6c203780bfbe Converted lstsq to new template form Nishanth <nishanth@fossee.in> parents: diff changeset	4	1. What does ones_like([1, 2, 3]) produce
6c203780bfbe Converted lstsq to new template form Nishanth <nishanth@fossee.in> parents: diff changeset	5
6c203780bfbe Converted lstsq to new template form Nishanth <nishanth@fossee.in> parents: diff changeset	6	a. array([1, 1, 1])
6c203780bfbe Converted lstsq to new template form Nishanth <nishanth@fossee.in> parents: diff changeset	7	#. [1, 1, 1]
6c203780bfbe Converted lstsq to new template form Nishanth <nishanth@fossee.in> parents: diff changeset	8	#. [1.0, 1.0, 1.0]
6c203780bfbe Converted lstsq to new template form Nishanth <nishanth@fossee.in> parents: diff changeset	9	#. Error
6c203780bfbe Converted lstsq to new template form Nishanth <nishanth@fossee.in> parents: diff changeset	10
330 efb8ddf26aff Finished lstsq Nishanth <nishanth@fossee.in> parents: 237 diff changeset	11	Answer: array([1, 1, 1])
efb8ddf26aff Finished lstsq Nishanth <nishanth@fossee.in> parents: 237 diff changeset	12
237 6c203780bfbe Converted lstsq to new template form Nishanth <nishanth@fossee.in> parents: diff changeset	13	2. What does ones_like([1.2, 3, 4, 5]) produce
6c203780bfbe Converted lstsq to new template form Nishanth <nishanth@fossee.in> parents: diff changeset	14
6c203780bfbe Converted lstsq to new template form Nishanth <nishanth@fossee.in> parents: diff changeset	15	a. [1.2, 3, 4, 5]
6c203780bfbe Converted lstsq to new template form Nishanth <nishanth@fossee.in> parents: diff changeset	16	#. array([1.0, 1.0, 1.0, 1.0])
6c203780bfbe Converted lstsq to new template form Nishanth <nishanth@fossee.in> parents: diff changeset	17	#. array([1, 1, 1, 1])
6c203780bfbe Converted lstsq to new template form Nishanth <nishanth@fossee.in> parents: diff changeset	18	#. array([1.2, 3, 4, 5])
6c203780bfbe Converted lstsq to new template form Nishanth <nishanth@fossee.in> parents: diff changeset	19
330 efb8ddf26aff Finished lstsq Nishanth <nishanth@fossee.in> parents: 237 diff changeset	20	Answer: array([1.0, 1.0, 1.0, 1.0])
237 6c203780bfbe Converted lstsq to new template form Nishanth <nishanth@fossee.in> parents: diff changeset	21
330 efb8ddf26aff Finished lstsq Nishanth <nishanth@fossee.in> parents: 237 diff changeset	22	3. The plot of ``u`` vs ``v`` is a bunch of scattered points that show a
efb8ddf26aff Finished lstsq Nishanth <nishanth@fossee.in> parents: 237 diff changeset	23	linear trend. How do you find the least square fit line of ``u`` vs ``v``.
efb8ddf26aff Finished lstsq Nishanth <nishanth@fossee.in> parents: 237 diff changeset	24
efb8ddf26aff Finished lstsq Nishanth <nishanth@fossee.in> parents: 237 diff changeset	25	Answer::
efb8ddf26aff Finished lstsq Nishanth <nishanth@fossee.in> parents: 237 diff changeset	26
efb8ddf26aff Finished lstsq Nishanth <nishanth@fossee.in> parents: 237 diff changeset	27	A = array(u, ones_like(u)).T
efb8ddf26aff Finished lstsq Nishanth <nishanth@fossee.in> parents: 237 diff changeset	28	result = lstsq(A, v)
efb8ddf26aff Finished lstsq Nishanth <nishanth@fossee.in> parents: 237 diff changeset	29	m, c = result[0]
efb8ddf26aff Finished lstsq Nishanth <nishanth@fossee.in> parents: 237 diff changeset	30
efb8ddf26aff Finished lstsq Nishanth <nishanth@fossee.in> parents: 237 diff changeset	31	lst_line = m * u + c
efb8ddf26aff Finished lstsq Nishanth <nishanth@fossee.in> parents: 237 diff changeset	32

author	Amit Sethi
	Fri, 12 Nov 2010 02:01:28 +0530
changeset 487	cb3974daced5
parent 330	efb8ddf26aff
permissions	-rw-r--r--