How to plot an ellipse with the equation in Robert H. Bishop's book

[The cat]

Hi,

I've been trying to plot the ellipse with the equation on Page 232, Q E7.3 of Dr. Robert H. Bishop's book.

I am currently stuck as I am unable to find a solution for this. Below is the equation which is required to 

be used.

r^2= A^2*B^2/(A^2*sin^2(ф)+B^2cos^2(ф))

inputs are A, B and r with 0 <= ф <= 2*pi

Anyone got a suggestion on this? Thanks a million!

[Coq_Rouge]

You have to use a XY graph. and plot the ellipse as a series of points describing x, and y positions. Equal to point P in the attachment. Hint Google and Wikipedia is your friends  ;). But feel free to post any question regarding Labview code for your school assignment 

Message Edited by t06afre on 03-23-2009 01:44 PM

[CMal]

Duplicate post.

[CoastalMaineBird]

I just built a VI to graph an ellipse with that equation and it works fine, although R is not an input.

Looks like "A" is the X-axis radius, and "B" is the Y-axis radius. 

What part are you having trouble with? 

[The cat]

Hi Steve Bird

Up until now I am able to plot the ellipse but the direction of the ellipse is not the same as in Robert's book.

In Robert's book, the ellipse is displayed horizontally but mine is displayed vertically. Any idea how do i rotate

the ellipse?

Thank you.

[CoastalMaineBird · Accepted solution]

If "A" is the X-axis radius, and "B" is the Y-axis radius, then what happens if you swap A and B? 

[altenbach]

Typically, you can eliminate all trigonometry by using complex math. xy graphs directly accept complex numbers, in which case they will graph in the complex plane. That's what you want!

Here is an example I made long ago in LabVIEW 7.0 (Ellipse2.vi), maybe it can give you a few more ideas. 🙂

(see also this old thread)

[The cat]

Hi Chris M, Steve Bird, Altenbach

U guys have been a great help!

Thanks!!

[isramadrid]

Absolutely perfect. Thanks!