Homework 5, due October 8, 2014.

Due 9:25am, Wednesday, October 8, 2014.
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goodwine
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Homework 5, due October 8, 2014.

Post by goodwine »

Reading: Chapter 4.

Exercises: 4.3, 4.4, 4.6, 4.7, 4.9, 4.12, 4.14 and 4.15.

In 4.6, you do not have to write a computer program, i.e., ignore the sentence starting with "Demonstrate whether..."
Bill Goodwine, 376 Fitzpatrick
ksmith44

Re: Homework 5, due October 8, 2014.

Post by ksmith44 »

I am having a bit of a difficulty with the phase angle plot for 4.3. I am getting a jump after the ratio = 1, and unwrap() is not working. How can I correct that?
goodwine
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Re: Homework 5, due October 8, 2014.

Post by goodwine »

ksmith44 wrote:I am having a bit of a difficulty with the phase angle plot for 4.3. I am getting a jump after the ratio = 1, and unwrap() is not working. How can I correct that?
If the answer is basically right, but only shifted by pi or something, then you don't have to fix it. A couple things that might help are atan2(), plotting it in sections and adding or subtracting pi in the part that needs to be shifted. Again, though, if it's right, but just looks bad, it's not required for you to get the plot to be pretty.
Bill Goodwine, 376 Fitzpatrick
ksmith44

Re: Homework 5, due October 8, 2014.

Post by ksmith44 »

Using atan2() fixed it! Thanks.
mmulvihill

Re: Homework 5, due October 8, 2014.

Post by mmulvihill »

Could somebody please explain how to properly use atan2()? I'm very confused on what I need to do in order to properly use the function because I do not understand what it does.
goodwine
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Re: Homework 5, due October 8, 2014.

Post by goodwine »

mmulvihill wrote:Could somebody please explain how to properly use atan2()? I'm very confused on what I need to do in order to properly use the function because I do not understand what it does.
It is able to determine which quadrant the inverse tangent function is because it keeps track of the sign of x and y: http://www.mathworks.com/help/matlab/re ... #buct8h0-4

In other words, it can distinguish atan((-x)/(-y)) and atan(x/y), but regular atan() cannot.
Bill Goodwine, 376 Fitzpatrick
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