Plotting Sound Pressure Level
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Hi,
So I am trying to plot the eqution:
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/196725/image.png)
The final solution should look like what is attached. I constructed it using a loop but I don't think I'm follwoing the right steps.. For some reason it just says R is equal to 1000 and does not give me values between 1 to 1000.
r = 45;
alpha = .005;
W = .01;
Wref = 1*10^-12;
Lw = 10*log(W/Wref)
for R = 1:1000
Lp(R) = Lw-10*log10(2*pi*r^2)-alpha*R;
end
Thanks, anything would help.
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Answers (1)
Image Analyst
on 26 Nov 2018
Edited: Image Analyst
on 26 Nov 2018
Instead of
for R = 1:1000
Lp(R) = Lw-10*log10(2*pi*r^2)-alpha*R;
end
do it vectorized
alpha = .005;
W = .01;
Wref = 1*10^-12;
Lw = 10*log(W/Wref)
R = 1 : 1000
Lp = Lw - 10*log10(2*pi*R.^2) - alpha*R;
plot(R, Lp, 'b-', 'LineWidth', 2)
grid on;
xlabel('R', 'FontSize', 15);
ylabel('Lw', 'FontSize', 15);
This assumes your formula for Lw is correct.
![0000 Screenshot.png](https://www.mathworks.com/matlabcentral/answers/uploaded_files/196748/0000%20Screenshot.png)
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