MATLAB Answers

Converting a linear equation to decibel

3 views (last 30 days)
flanker989
flanker989 on 18 Sep 2021
Commented: Star Strider on 18 Sep 2021
I'm trying to convert a linear polar plot to decibel but I don't know how to proceed. Here is the original:
theta = 2*pi*linspace(0, 1, 30);
r = cos(theta/2).^2;
polar(theta, r, 'r-');
This is my progress so far:
theta = 2*pi*linspace(0, 1, 30);
r = 10*log10(abs(cos(theta/2).^2));
b = find(r(-40))
b == -40
b = b + 40
polardb(theta, r, -40, 'r-');
I don't know how to proceed.

Accepted Answer

Star Strider
Star Strider on 18 Sep 2021
The ‘theta’ vector likely needs to have more points, however that appears to be correct.
I use a slightly different approach here —
theta = 2*pi*linspace(0, 1, 30);
r = cos(theta/2).^2;
figure
polarplot(theta, r, 'r-')
title('r(\theta)')
figure
polarplot(theta, mag2db(r), 'r-')
title('r(\theta) (dB)')
rt = rticklabels;
rticklabels(cellfun(@(x)sprintf('%s dB',x),rt', 'Unif',0))
.
  2 Comments
Star Strider
Star Strider on 18 Sep 2021
My pleasure!
If my Answer helped you solve your problem, please Accept it!
.

Sign in to comment.

More Answers (0)

Tags

Products


Release

R2020b

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!