Help with for loop array plotting

I cannot figure out why I have no output for the displacement response graphs in my code. Help!

clear all
close all
clc
 
data=xlsread('NS record 1940 El Centro Earthquake.xlsx');
t=data(:,1)';
ac=data(:,2)';
 
acc=ac*9.8;
 
figure(1)
plot(t,ac)
title('Ground Acceleration')
 
% zeta=2/100; 
 
% T0=1;
% omega=2*pi/T0; %omega=2*pi/T0
% omegad=omega*sqrt(1-zeta^2); 
% k=10;
% m=k/(omega^2);
m=1;
 
% amplitude=0.5;
% tmax=5; 
% Tp=0.5;
dtau=0.02;
 
Tnset=[0.5 1 2 2 2 2];
zetaset=[0.02 0.02 0.02 0 0.02 0.05];
omegaset=2*pi./Tnset; %omega=2*pi/T0
omegadset=omegaset.*sqrt(1-zetaset.^2);
 
for k=1:length(Tnset)
    for j=1:length(t)
        if j<=3
            Ae(j)=(t(j)/3)*...
                (acc(j)*(-zetaset(k)*omegaset(k)*t(j+3))+...
                4*acc(j)*exp(-zetaset(k)*omegaset(k)*t(j+2))*cos(omegadset(k)*t(j))+...
                2*acc(j)*exp(-zetaset(k)*omegaset(k)*t(j+1))*cos(omegadset(k)*t(j+1))+...
                4*acc(j+2)*exp(-zetaset(k)*omegaset(k)*t(j))*cos(omegadset(k)*t(j+2))+...
                acc(j+3)*cos(omegadset(k)*t(j+3)));
            Be(j)=(dtau/3)*...
                (acc(j)*(-zetaset(k)*omegaset(k)*t(j+3))+...
                4*acc(j)*exp(-zetaset(k)*omegaset(k)*t(j+2))*sin(omegadset(k)*t(j))+...
                2*acc(j)*exp(-zetaset(k)*omegaset(k)*t(j+1))*sin(omegadset(k)*t(j+1))+...
                4*acc(j+2)*exp(-zetaset(k)*omegaset(k)*t(j))*sin(omegadset(k)*t(j+2))+...
                acc(j+3)*cos(omegadset(k)*t(j+3)));
        else
            Ae(j)=(t(j-3)/3)*...
                (acc(j-3)*(-zetaset(k)*omegaset(k)*t(j))+...
                4*acc(j-3)*exp(-zetaset(k)*omegaset(k)*t(j-1))*cos(omegadset(k)*t(j-3))+...
                2*acc(j-3)*exp(-zetaset(k)*omegaset(k)*t(j-3))*cos(omegadset(k)*t(j-2))+...
                4*acc(j-1)*exp(-zetaset(k)*omegaset(k)*t(j-3))*cos(omegadset(k)*t(j-1))+...
                acc(j)*cos(omegadset(k)*t(j)));
            Be(j)=(t(j-3)/3)*...
                (acc(j-3)*(-zetaset(k)*omegaset(k)*t(j))+...
                4*acc(j-3)*exp(-zetaset(k)*omegaset(k)*t(j-1))*sin(omegadset(k)*t(j-3))+...
                2*acc(j-3)*exp(-zetaset(k)*omegaset(k)*t(j-3))*sin(omegadset(k)*t(j-2))+...
                4*acc(j-1)*exp(-zetaset(k)*omegaset(k)*t(j-3))*sin(omegadset(k)*t(j-1))+...
                acc(j)*cos(omegadset(k)*t(j)));
        end
        un(j)=(1/(m*omegadset(k)))*(Ae(j)*sin(omegadset(k)*t(j))-Be(j)*cos(omegadset(k)*t(j)));
    end
    figure('Name','Displacement Plot','NumberTitle','off');
    plot(t,un(k))
%     figure('Name','Plots','NumberTitle','off');
%     %title('Tn = ',Tnset(k),' sec, zeta = ',zetaset(k))
end
 
% tiledlayout(3,2);
% nexttile
% for k=1:length(Tnset)
%     nexttile
% end

[KSSV]

What you have done in for loop can be done without it.....

[Laura Bell]

I'm not sure what you mean..

Answer 1

[Naga]

Without the exact error message, it is really hard to help. However, based on the information provided, here are some points to consider:

1. You're using t(j+3) and t(j-3) in your computations for Ae and Be. Ensure that your data array t is large enough to accommodate these indices. If j is near the beginning or end of the array, you might be accessing out-of-bounds indices, leading to errors or unexpected behavior.
2. You're plotting un(k) instead of un in your loop. Since un is an array of displacement responses, you should plot the entire array un for each k.
3. The plot function should be plot(t, un) instead of plot(t, un(k)).

Answer 2

[VBBV]

@Laura Bell You can use loop index to retain values for each iteration in the loop.

However, for plotting graphs you need arrays if you dont use markers in plot function.

To ensure graphs are retained for every iteration, use tiledlayout and hold on functions

clear all
close all
clc
 
data=xlsread('NS record 1940 El Centro Earthquake.xlsx');
t=data(:,1)';
ac=data(:,2)';
 
acc=ac*9.8;
 
figure(1)
plot(t,ac)
title('Ground Acceleration')
 
% zeta=2/100; 
 
% T0=1;
% omega=2*pi/T0; %omega=2*pi/T0
% omegad=omega*sqrt(1-zeta^2); 
% k=10;
% m=k/(omega^2);
m=1;
 
% amplitude=0.5;
% tmax=5; 
% Tp=0.5;
dtau=0.02;
 
Tnset=[0.5 1 2 2 2 2];
zetaset=[0.02 0.02 0.02 0 0.02 0.05];
omegaset=2*pi./Tnset; %omega=2*pi/T0
omegadset=omegaset.*sqrt(1-zetaset.^2);
tiledlayout

for k=1:length(Tnset)
    for j=1:length(t)
        if j<=3
            Ae(j)=(t(j)/3)*...
                (acc(j)*(-zetaset(k)*omegaset(k)*t(j+3))+...
                4*acc(j)*exp(-zetaset(k)*omegaset(k)*t(j+2))*cos(omegadset(k)*t(j))+...
                2*acc(j)*exp(-zetaset(k)*omegaset(k)*t(j+1))*cos(omegadset(k)*t(j+1))+...
                4*acc(j+2)*exp(-zetaset(k)*omegaset(k)*t(j))*cos(omegadset(k)*t(j+2))+...
                acc(j+3)*cos(omegadset(k)*t(j+3)));
            Be(j)=(dtau/3)*...
                (acc(j)*(-zetaset(k)*omegaset(k)*t(j+3))+...
                4*acc(j)*exp(-zetaset(k)*omegaset(k)*t(j+2))*sin(omegadset(k)*t(j))+...
                2*acc(j)*exp(-zetaset(k)*omegaset(k)*t(j+1))*sin(omegadset(k)*t(j+1))+...
                4*acc(j+2)*exp(-zetaset(k)*omegaset(k)*t(j))*sin(omegadset(k)*t(j+2))+...
                acc(j+3)*cos(omegadset(k)*t(j+3)));
        else
            Ae(j)=(t(j-3)/3)*...
                (acc(j-3)*(-zetaset(k)*omegaset(k)*t(j))+...
                4*acc(j-3)*exp(-zetaset(k)*omegaset(k)*t(j-1))*cos(omegadset(k)*t(j-3))+...
                2*acc(j-3)*exp(-zetaset(k)*omegaset(k)*t(j-3))*cos(omegadset(k)*t(j-2))+...
                4*acc(j-1)*exp(-zetaset(k)*omegaset(k)*t(j-3))*cos(omegadset(k)*t(j-1))+...
                acc(j)*cos(omegadset(k)*t(j)));
            Be(j)=(t(j-3)/3)*...
                (acc(j-3)*(-zetaset(k)*omegaset(k)*t(j))+...
                4*acc(j-3)*exp(-zetaset(k)*omegaset(k)*t(j-1))*sin(omegadset(k)*t(j-3))+...
                2*acc(j-3)*exp(-zetaset(k)*omegaset(k)*t(j-3))*sin(omegadset(k)*t(j-2))+...
                4*acc(j-1)*exp(-zetaset(k)*omegaset(k)*t(j-3))*sin(omegadset(k)*t(j-1))+...
                acc(j)*cos(omegadset(k)*t(j)));
        end
        un(j,k)=(1/(m*omegadset(k)))*(Ae(j)*sin(omegadset(k)*t(j))-Be(j)*cos(omegadset(k)*t(j)));
    end
    %figure('Name','Displacement Plot','NumberTitle','off');
    nexttile 
    plot(t,un(:,k))
    hold on
%     figure('Name','Plots','NumberTitle','off');
%     %title('Tn = ',Tnset(k),' sec, zeta = ',zetaset(k))
end
 

% nexttile
% for k=1:length(Tnset)
%     nexttile
% endclose allclc data=xlsread('NS record 19etaset.^2); for k=1:length(Tnset)  for j=1:length(t)      if j<=3          Ae(j)=(t(j)/3)*...              (acc(j)*(-zetaset(k)*omegaset(k)*t(j+3))+...              4*acc(j)*exp(-zetaset(k)*omegaset(k)*t(j+2))*cos(omegadset(k)*t(j))+...              2*acc(j)*exp(-zetaset(k)*omegaset(k)*t(j+1))*cos(omegadset(k)*t(j+1))+...              4*acc(j+2)*exp(-zetaset(k)*omegaset(k)*t(j))*cos(omegadset(k)*t(j+2))+...              acc(j+3)*cos(omegadset(k)*t(j+3)));          Be(j)=(dtau/3)*...              (acc(j)*(-zetaset(k)*omegaset(k)*t(j+3))+...              4*acc(j)*exp(-zetaset(k)*omegaset(k)*t(j+2))*sin(omegadset(k)*t(j))+...              2*acc(j)*exp(-zetaset(k)*omegaset(k)*t(j+1))*sin(omegadset(k)*t(j+1))+...              4*acc(j+2)*exp(-zetaset(k)*omegaset(k)*t(j))*sin(omegadset(k)*t(j+2))+...              acc(j+3)*cos(omegadset(k)*t(j+3)));      else          Ae(j)=(t(j-3)/3)*...              (acc(j-3)*(-zetaset(k)*omegaset(k)*t(j))+...              4*acc(j-3)*exp(-zetaset(k)*omegaset(k)*t(j-1))*cos(omegadset(k)*t(j-3))+...              2*acc(j-3)*exp(-zetaset(k)*omegaset(k)*t(j-3))*cos(omegadset(k)*t(j-2))+...              4*acc(j-1)*exp(-zetaset(k)*omegaset(k)*t(j-3))*cos(omegadset(k)*t(j-1))+...              acc(j)*cos(omegadset(k)*t(j)));          Be(j)=(t(j-3)/3)*...              (acc(j-3)*(-zetaset(k)*omegaset(k)*t(j))+...              4*acc(j-3)*exp(-zetaset(k)*omegaset(k)*t(j-1))*sin(omegadset(k)*t(j-3))+...              2*acc(j-3)*exp(-zetaset(k)*omegaset(k)*t(j-3))*sin(omegadset(k)*t(j-2))+...              4*acc(j-1)*exp(-zetaset(k)*omegaset(k)*t(j-3))*sin(omegadset(k)*t(j-1))+...              acc(j)*cos(omegadset(k)*t(j)));      end      un(j)=(1/(m*omegadset(k)))*(Ae(j)*sin(omegadset(k)*t(j))-Be(j)*cos(omegadset(k)*t(j)));  end  figure('Name','Displacement Plot','NumberTitle','off');  plot(t,un(k))%     figure('Name','Plots','NumberTitle','off');%     %title('Tn = ',Tnset(k),' sec, zeta = ',zetaset(k))end % tiledlayout(3,2);% nexttile% for k=1:length(Tnset)%     nexttile% end