How to plot absorption of sound waves in seawater and boric acid?

Please provide a Matlab code for the figure below.

Answer 1

[Stephan]

% Produce some data
x = logspace(-1,2);
y1 = exp(x);
y2 = (exp(x)./exp(y1));

% Plot lo double log-scale
loglog(x,y1,'--k','LineWidth',2)
hold on
loglog(x,y2,'-k','LineWidth',2)
hold off

% Change look
a = gca;
grid on
xlabel('Frquency - kHz')
ylabel('Attenuation - dB/km')
legend({'Saltwater', 'MgSO_{4}'}, 'Interpreter', 'tex', 'Location', 'southeast')
a.GridLineStyle = '--';
a.MinorGridLineStyle = '--';
a.GridColor = 'k';
a.MinorGridColor = 'k';
a.GridAlpha = 1;
a.MinorGridAlpha = 1;

[Junaid Qadir]

Dear Stephan, I am really thankfull of your great efforts. Would you please add two more parameters i,e Freshawater and B(OH)3 ????

Secondly, the line in the figure moving upward but in your polt it moves downward. Please, I need exact the same plot which I have uploaded in the figure.

I am extremly thankful to you. Many Many thanks in advance,

[Stephan]

This was only a simple example of how you start with it. To plot exactly the same, you will need data or equations to calculate.

[Junaid Qadir]

Thank you so much for the kind help. Would you be kind enough to pelase help me in another plot?

I want to plot as presented below in figure. How can I plot it?

The sound speed is 1500m/s in water. And the depth is considered as 5000 meters.

Bundle of thanks

[Stephan]

you might want to plot a parametric curve. Here is an example:

<https://de.mathworks.com/help/matlab/ref/fplot.html?searchHighlight=fplot&s_tid=doc_srchtitle#bu6xntl-12>

As already pointed out, you will need the equations or data to plot your curve.

[Junaid Qadir]

Thank you so much for your kind help.

[Junaid Qadir]

Dear Stephan, please see code below and kindly let me know where is the problem occuring? Why the plot does not draw? I think there is some missing of ''for loop''.

%*************   Junaid Qadir  *************% 
%*************   MPhil Electronics  *************%
%*************   Department of Electronics *************%
%*************   Quaid-i-Azam University Islamabad,45320, Pakistan  *************%
% %*************   Email: [e-mail]  , Instagram: @junaid_qadar,  Facebook: https://web.facebook.com/junaid.qadar*************%


%%%%%%%%%%%%% BORIC ACID + Magnesium sulphate+ Pure water 

clear all 
close all 
clc
f= 30; % kHz
S= 35; % salinity
T=10; % temmperature in degree centi grad
pH= 7.8;
theta= 273+T;
D= 500; % Depth in meter
c = 1449 + 4.591 *T - 5.304 * 10^(-2)*T^(2) + 2.374 * 10^ (-4) * T^(3) + 1.34*(S - 35) ...
+ 1.63 * 10^(-2) * D + 1.675 * 10^(-7)* D + 1.025* 10^(-2)* T*(S - 35) - 7.139* 10^(-3)*T*D^3;  % Sound Speed in water = 1500 m/s


p1= 1;  % pressur 1
p2= 1-1.37* 10^(-4) *D +6.2*10^(-9)* D^2; % pressure 2
p3= 1-3.83*10^(-5) * D+4.9*10^(-10) *D^2;  % Pressur 3


f1= 0.78* sqrt(S/35)*10^(T/26); % frequency 1
f2= 8.17*10^(8-1990/theta); %fruency 2

A1= 8.86/c*10^(0.78*pH-5); % Absorption
A2= 21.44* S/c*(1+0.025*T);   % Absorption
A3= 3.964*10^(-4)- 1.146* 10^(-5)*T +1.45*10^(-7)*T^2-6.5*10^(-10)*T^3; % Absorption

Boric_acid= A1*p1*f1*f/ f1^2*f^2;  % Formula for Boric acid
Magnesium_sulphate= A2*p2*f2*f^2/ f2^2+f^2; % Formula for Magnesium sulphate
Pure_water= A3*p3*f^2; % pure water 
 Total= Boric_acid+ Magnesium_sulphate + Pure_water;  %  Total Absorption
 
% Plot to double log-scale
loglog(Boric_acid,f,'--r','LineWidth',2)
hold on
loglog(Magnesium_sulphate,f,'-*k','LineWidth',2)
hold on
loglog(Pure_water,f,'-.*g','LineWidth',2)
hold on
loglog( Total,f,'--hb','LineWidth',2)
hold off
% Change look
a = gca;
grid on
xlabel('Frquency - kHz')
ylabel('Attenuation - dB/km')
legend({'Boric acid', 'MgSO_{4}', 'Pure water ', 'Total absorption'}, 'Interpreter', 'tex', 'Location', 'southeast')
a.GridLineStyle = '--';
a.MinorGridLineStyle = '--';
a.GridColor = 'k';
a.MinorGridColor = 'k';
a.GridAlpha = 1;
a.MinorGridAlpha = 1;