Phase Plots Dropping when quadrant changes

I am trying to plot the phase of a vibratory system with base excitation. I did the magnitude, but the phase is giving me problems. How can I make my equations so the phase equations are continuous and do not suddenly drop when the quadrant changes? atan2d does not show up with anything. Using atand shows the below result:

It should look something the phase plot on the top right of this:

Heres my code:

Answer 1

[Star Strider]

Use either the angle function or atan2d for this. The angle function returns the angle of a complex variable in radians, so you will need to use the rad2deg function with its output.

[Austin]

I tried atan2d, it comes up with a blank plot. I've used angle before so Ill give that a shot

[Star Strider]

For atan2d, you need to enter the arguments as:

P = @(r) atan2d(2*SR.*r.^3, 1+(4.*SR.^2-1).*r.^2);

Here, the ‘y’ argument is first, ‘x’ second. I also used element-wise operations, since I assume ‘r’ is a vector. Unless you specifically intend matrix operations, use element-wise operations if any of the variables are arrays..

If ‘r’ is complex, consider:

P = @(r) atan2d(2*SR.*imag(r).^3, 1+(4.*SR.^2-1).*real(r).^2);

I don’t know what your variables are, so this is a guess on my part.

.

[Sam Chak]

Hi Austin,

Please share the full code for evaluation. You can click on the indentation icon and copy/paste the code to the grey field.