getting errors while trying to plot

I'm trying to plot this but I'm getting errors. Not sure how to fix them. Any help will be greatly appreciated. Thanks much.

    % Toggle display for troubleshooting
    % disp(['Calculating Streamwise Position ' ...
    %    num2str(LCVx) ' of ' num2str(Nx) ' (x = ' ...
    %    num2str(x(LCVx)) ' m)'])

    % Solve for u at the next x location
    % ENTER CODE HERE %
    n=LCVx-1;
    u_ns(1)=0;
    u_ns(M)=Ue(n+1);
    for mi =2:M-1
        Q=nu*delta_x/u(mi)/delta_y^2;
        P=1/2*delta_x/delta_y*v(mi)/u(mi);
        u_ns(mi) = u(mi)+Ue(n)/u(mi)*(Ue(n+1)-Ue(n))+...
            Q*(u(mi+1)-2*u(mi)+u(mi-1))-...
            P*(u(mi+1)-u(mi-1));
    end

    % Solve for v at the next x location using the continuity equation
    % ENTER CODE HERE %
    v_ns(1)=0;
    for mi =2:M
        P=1/2*delta_y/delta_x;
        v_ns(mi) = v_ns(mi-1)- ...
            P*(u_ns(mi)-u(mi)+u_ns(mi-1)-u(mi-1));
    end

    % Update velocity profiles
    u = u_ns;
    v = v_ns;

    % Calculate momentum thickness
    % ENTER CODE HERE %
    uf = @(z)interp1(y,u,z);
    thetafun = @(z)uf(z).*(1-uf(z));
    theta(LCVx) = integral(thetafun,min(y),max(y));

    % Calculate skin friction coefficient
    % ENTER CODE HERE %
    cf(LCVx) =((nu/dy)/Uef (xstart)^2)*(4*u(2)-u(3));
    if mod(n,500)==0
        figure;subplot(1,2,1);plot(y,u_ns);subplot(1,2,2);plot(y,v_ns);
        pause;
    end

end uplots = u./Ue; yplots = y./theta; for x = xstart:0.2:xend figure hold on plot(y,u) figure hold on plot(yplots,uplots)

    end

[Fangjun Jiang]

load() is used for .mat file. For .txt file, you might be able to use readmatrix()

[Cesar Cardenas]

Right, how do I have to modify the code? Not sure about it. Thanks

[Cesar Cardenas]

Basically, what I am trying to do is plot u vs y, and u/Ue vs y/theta every 0.1 m on one plot. Not sure how to pause the code every 0.1 x steps (start at 0.2, pause at 0.3, etc) so that I can get the u, y, theta, and Ue at those points. Any help will be appreciated. Thanks

[Cris LaPierre]

Attach your text files to your post using the paperclip icon, and then we can say for certain.

[Cesar Cardenas]

Thanks for your reply. Enclosed the txt files.

Answer 1

[Mathieu NOE]

the error message is quite clear

Unable to find file or directory 'negm_profiles.txt'.

this file is not in your directory

double check by typing in your command window

dir *.txt

if you need more help , it's genrally a good thing to share your data files along the code

[Mathieu NOE]

@Cesar Cardenas

your code works fine with the provided txt files.

the next problem is here , here arrays size are not matching

uplots = u./Ue;
yplots = y./theta;

u and y are 300x1 arrays while Ue and theta are 8001x1 arrays

which one is the good size and how will you modify the code accordingly ?