How to optimize my code (plotting imported data)

I am plotting the mass flow rate Q over the square root of a pressure diference. The result should look as follows

I managed to plot it but my actual code is quite inefficent. I am trying to optimize my code, so that it is more efficient and easily understood by others. I am quite convinced it can be easily improved using vectors. For instance, notice how I have to change values for each Q manually...

Here is the code for just the first two points. For the other 8 I followed the same procedure.

clc
close all
clear all
warning('OFF', 'MATLAB:table:ModifiedAndSavedVarnames')

p_in=9.04;

p_out=[8.06 7.8 7.6 7.4 7.0 6.8 6.6 6.4 6.2 6.0];

p_sat=6.35;

Area = 3.14*(0.015/2).^2;

%How to generalize Q=rho*area*magnitudeOfTheVelocity?

A = readtable("surfaceFieldValue1eNEG06Inlet.dat");
rho = A{:,"Var2"}; %density

rho_last100values = rho(end-100:end); %From this array we'll extract last 100 values

M_rho_last100values=mean(rho_last100values,"all"); %mean value of the last 100 values

%CODE TO GET THE FIRST POINT (Outlet pressure p=8.06 bar)

Ux_A = A{:,"Var3"}; %velocity component

Uy_A = A{:,"Var4"}; %velocity component

Uz_A = A{:,"Var5"}; %velocity component

U_A = sqrt(Ux_A.^2 + Uy_A.^2 + Uz_A.^2); %magnitude of the velocity

UA_last100values = U_A(end-100:end); %las 100 values of the magnitude of the velocity

M_UA_last100values=mean(UA_last100values,"all"); %mean value of the last 100 values

Q_8_06bar = M_rho_last100values.*Area.*M_UA_last100values %we just apply the definition of mass flow rate Q, that is Q=rho*area*magnitudeOfTheVelocity

sqrtDeltaP_8_06bar=sqrt(p_in-p_out(1));%calculate the square root of the pressure difference; the pressure at the inlet is always 9.04

%REPEAT THE ABOVE FOR THE NEXT POINT

%Outlet pressure p=7.8 bar

B = readtable("surfaceFieldValue_0.007001.dat");
 
Ux_B = B{:,"Var3"};
Uy_B = B{:,"Var4"};
Uz_B = B{:,"Var5"};
U_B = sqrt(Ux_B.^2 + Uy_B.^2 + Uz_B.^2);
UB_last100values = U_B(end-100:end);
M_UB_last100values=mean(UB_last100values,"all");
 
Q_7_8bar = M_rho_last100values.*Area.*M_UB_last100values 

sqrtDeltaP_7_8bar=sqrt(p_in-p_out(:,2));

Q = [Q_8_06bar;Q_7_8bar];

sqrtDeltaP = [sqrtDeltaP_8_06bar;sqrtDeltaP_7_8bar];

%Q plot
figure
plot(sqrtDeltaP,Q,'*','LineWidth',1.5)
legend('Outlet pressure 8 bar','Outlet pressure 7.8 bar','Outlet pressure 7.6 bar','Outlet pressure 7.4 bar','Outlet pressure 7.0 bar','Outlet pressure 6.8 bar','Outlet pressure 6.6 bar','Outlet pressure 6.4 bar','Outlet pressure 6.2 bar','Outlet pressure 6.0 bar','Location','bestoutside')
xlabel('sqrt Delta p')
ylabel('Q [kg/s]')
axis square;
grid on;

The needed files are in the Optimization Data folder here: https://drive.google.com/drive/folders/1CgeDuCahVZvLXXkNkGWlPg8lSGyurmI3

Could you please guide me on how to optimize it? Thank you :)

[JD_PM]

I edited my post, adding comments to my code; hopefully is easier to understand. Please let me know if further clarification would be helpful :)

[Jan]

What do you want to improve?

I'd omit the useless clear all because it wastes time with no benefits. It is "cargo cult programming". Use functions instead of scripts to keep the workspace clean.

Answer 1

[Shushant]

Hi JD_PM,

I understand that you want to make your code more readable and scalable. As mentioned by Jan in the comments you can do so by using "function".

Take the section of code which is being repeated multiple times and convert it into a "function". Refer to the following code snippet where I have made a function which takes the "fileName" and "Area" as input and returns the value of "Q" as output-

p_in=9.04;
p_out=[8.06 7.8 7.6 7.4 7.0 6.8 6.6 6.4 6.2 6.0];
p_sat=6.35;
Area = 3.14*(0.015/2).^2;
%How to generalize Q=rho*area*magnitudeOfTheVelocity?
Q_8_06bar = myfunc("surfaceFieldValue1eNEG06.dat", Area); % Calling our function
sqrtDeltaP_8_06bar=sqrt(p_in-p_out(1));%calculate the square root of the pressure difference; the pressure at the inlet is always 9.04
Q_7_8bar = myfunc("surfaceFieldValue_0.116312.dat", Area); % Calling our function
sqrtDeltaP_7_8bar=sqrt(p_in-p_out(:,2));
Q = [Q_8_06bar; Q_7_8bar];
sqrtDeltaP = [sqrtDeltaP_8_06bar; sqrtDeltaP_7_8bar];
%Q plot
figure
plot(sqrtDeltaP,Q,'*','LineWidth',1.5)
legend('Outlet pressure 8 bar','Outlet pressure 7.8 bar','Outlet pressure 7.6 bar','Outlet pressure 7.4 bar','Outlet pressure 7.0 bar','Outlet pressure 6.8 bar','Outlet pressure 6.6 bar','Outlet pressure 6.4 bar','Outlet pressure 6.2 bar','Outlet pressure 6.0 bar','Location','bestoutside')
xlabel('sqrt Delta p')
ylabel('Q [kg/s]')
axis square;
grid on;
function Q = myfunc(fileName, Area)
    A = readtable(fileName);
    rho = A{:,2}; % Will always consider the 2nd columns as the value of rho
    rho_last100values = rho(end-100:end); %From this array we'll extract last 100 values
    M_rho_last100values=mean(rho_last100values,"all"); %mean value of the last 100 values
    %CODE TO GET THE FIRST POINT (Outlet pressure p=8.06 bar)
    Ux_A = A{:,3}; %velocity component
    Uy_A = A{:,4}; %velocity component
    Uz_A = A{:,5}; %velocity component
    U_A = sqrt(Ux_A.^2 + Uy_A.^2 + Uz_A.^2); %magnitude of the velocity
    UA_last100values = U_A(end-100:end); %las 100 values of the magnitude of the velocity
    M_UA_last100values=mean(UA_last100values,"all"); %mean value of the last 100 values
    Q = M_rho_last100values.*Area.*M_UA_last100values; %we just apply the definition of mass flow rate Q, that is Q=rho*area*magnitudeOfTheVelocity
end

In a similar way, you can define a customized function that meets your specific needs. However, it is important to note that for the "function" to be simplified, all datasets should have the same structure. If the datasets differ significantly from each other, it may introduce complexity during the design of your "function".

Refer to the following documentation for more information on how to create your own "function"-

https://in.mathworks.com/help/matlab/ref/function.html

I hope this information helps in solving the issues you were facing.

Thank you,

Shushant