Plot from 26 by 20 matrix vs a 2D matrix

Hi, I am having trouble with plotting five figures from one 26 by 20 matrix, where the first four columns denote the y coordinates of the four lines of the first figure, the second four columns denote the y coordinates of the four lines of the secong figure, etc. However the x coordinates are stored in a 2D 26 by 5 matrix where the first column denotes the x coordinate for the first figure, the second column for the second figure, etc. I have tried something as follows:

for i5 = 0:N1:(N1*N1)
    %h1 = h(:,i5+1);
    %h2 = h(:,i5+2);
    %h3 = h(:,i5+3);
    %h4 = h(:,i5+4);
    
    lnNu_r1 = lnNu_r(:,i5+1);
    lnNu_r2 = lnNu_r(:,i5+2);
    lnNu_r3 = lnNu_r(:,i5+3);
    lnNu_r4 = lnNu_r(:,i5+4);
    
    % lnNu vs lnRe for effect of Ctflow
    figure(i5+2)
    plot(lnRe_phi(:,i5+1),lnNu_r1,'+')
    hold on
    plot(lnRe_phi(:,i5+1),lnNu_r2,'+')
    plot(lnRe_phi(:,i5+1),lnNu_r3,'+')
    plot(lnRe_phi(:,i5+1),lnNu_r4,'+')
    hold off
    title('Variation of ln(Local Nusselt Number) vs ln(Local Reynolds Number)')
    xlabel('ln(Re_\phi)') 
    ylabel('ln(Nu_r)')
    legend('{C}_{{w}_{1}}','{C}_{{w}_{2}}','{C}_{{w}_{3}}','{C}_{{w}_{4}}')
    grid
end

I think the issue lies about how the lnRe_phi is called but I have run out of ideas on how to do so.

Answer 1

[Voss]

If I understand correctly, the column used to get the x-coordinates out of the matrix lnRe_phi, needs to be 1, 2, 3, 4, 5 when i5 is 0, 4, 8, 12, 16. If that's right, then something like this would work:

% 26-by-5 matrix of x coordinates
lnRe_phi = linspace(0,5,26).'+(0:4)

lnRe_phi = 26×5

0 1.0000 2.0000 3.0000 4.0000 0.2000 1.2000 2.2000 3.2000 4.2000 0.4000 1.4000 2.4000 3.4000 4.4000 0.6000 1.6000 2.6000 3.6000 4.6000 0.8000 1.8000 2.8000 3.8000 4.8000 1.0000 2.0000 3.0000 4.0000 5.0000 1.2000 2.2000 3.2000 4.2000 5.2000 1.4000 2.4000 3.4000 4.4000 5.4000 1.6000 2.6000 3.6000 4.6000 5.6000 1.8000 2.8000 3.8000 4.8000 5.8000

% 26-by-20 matrix of y coordinates
lnNu_r = randn(26,20);

N1 = 4;

for i5 = 0:N1:(N1*N1)
    %h1 = h(:,i5+1);
    %h2 = h(:,i5+2);
    %h3 = h(:,i5+3);
    %h4 = h(:,i5+4);
    
    lnNu_r1 = lnNu_r(:,i5+1);
    lnNu_r2 = lnNu_r(:,i5+2);
    lnNu_r3 = lnNu_r(:,i5+3);
    lnNu_r4 = lnNu_r(:,i5+4);
    
    x_column = i5/N1+1;
    
    % lnNu vs lnRe for effect of Ctflow
    figure(i5+2)
    plot(lnRe_phi(:,x_column),lnNu_r1,'+')
    hold on
    plot(lnRe_phi(:,x_column),lnNu_r2,'+')
    plot(lnRe_phi(:,x_column),lnNu_r3,'+')
    plot(lnRe_phi(:,x_column),lnNu_r4,'+')
    hold off
    title('Variation of ln(Local Nusselt Number) vs ln(Local Reynolds Number)')
    xlabel('ln(Re_\phi)') 
    ylabel('ln(Nu_r)')
    legend('{C}_{{w}_{1}}','{C}_{{w}_{2}}','{C}_{{w}_{3}}','{C}_{{w}_{4}}')
    grid
end

[Karl Zammit]

Thanks a lot for your answer! Not sure how that would quite work for the i5=0 case, however looking at your results it seens as though it has.