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Final Project-Zhiwei Zhang #20

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@Zhiweix Zhiweix commented Dec 14, 2014

Spring-mass-damper system

Zhiweix added 2 commits December 14, 2014 16:08
Spring-mass-damper system
Spring-mass-damper system
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labarba commented Jan 6, 2015

The numerical content of this notebook is a little on the light side: it's a single application of the simplest numerical method we learned in this course (Euler's method). The derivation of the spring-mass-damper system is, of course, a standard textbook example and pretty close to the derivation on Wikipedia here:
http://en.wikipedia.org/wiki/Damping

The image you used on Figure 1 is found on this webpage:
http://www.roboticslab.ca/mass-spring-damper/#more-5
You did not credit this source, which is bad form —you must always credit your sources, and in the case of images, be careful about copyright issues!

The image used in Figure 2 is from your first reference, but you also did not include a credit line for the image.

Although you may find a lot of examples of people that assess the accuracy of a numerical result by the "eyeball metric" of making a plot and comparing with another result, this is not really a good metric. We discussed early in this course how to assess a numerical solution by looking at grid convergence, for example. And if you have an analytical solution, like in this case, you really want to calculate some error measure!

What is nice of your notebook is that you introduce the odeint function of the SciPy library, which we didn't learn in the course. What is NOT nice is that you copied the description of this function verbatim from this source (which remained uncited):
http://nbviewer.ipython.org/gist/dpsanders/d417c1ffbb76f13f678c

Typos & Style
This modal is what we are going to discuss—>This model ...
we will talk about muti-degree-of-freedom latter—>later
From Hooke's law of elasticity that the extension ...—>Hooke's law of elasticity says that the extension ...

LaTeX tip: use backslash before transcendental functions for them to appear in roman type, e.g., \cos, \sin

If you add a semi-colon at the end of your plotting statements, it suppresses the ugly Matplotlib output, like: Out[2]: <matplotlib.legend.Legend at 0x105f91a90

Both of the position and velocity experience ...—>Both the position and ...

More complicate systems—>complicated
sovle—>solve

There are also a bunch of either missing or misplaced articles (especially the definite article "the"), which is a common problem for ESL speakers of Asian origin. This is something you need to work on.
Try this online quiz for practice: http://a4esl.org/q/h/mc008-ld.html

cited sources and corrected some typos
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