Unable to perform assignment because the indices on the left side are not compatible with the size of the right side.

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Answer 1

[Torsten]

k1=180; k2=50; k3=220;
knew=linspace(k1*0.4,k1*1.6,20);
m1=1.1; m2=3.4;
for i=1:length(knew)  
    K{i}=[knew(i)+k2,-k2;-k2,k2+k3];
    M{i}=[m1,0;0,m2];
    lambda{i}=eig(double(K{i}),double(M{i})); 
    omega_nf{i}=sqrt(lambda{i});
end 
omega_nf{1:end}

ans = 2×1

8.0553 11.1997

ans = 2×1

8.1898 11.5578

ans = 2×1

8.2927 11.9257

ans = 2×1

8.3728 12.2973

ans = 2×1

8.4361 12.6686

ans = 2×1

8.4870 13.0371

ans = 2×1

8.5287 13.4012

ans = 2×1

8.5633 13.7599

ans = 2×1

8.5924 14.1128

ans = 2×1

8.6172 14.4595

ans = 2×1

8.6386 14.8002

ans = 2×1

8.6571 15.1347

ans = 2×1

8.6733 15.4633

ans = 2×1

8.6876 15.7861

ans = 2×1

8.7004 16.1032

ans = 2×1

8.7117 16.4149

ans = 2×1

8.7220 16.7215

ans = 2×1

8.7312 17.0229

ans = 2×1

8.7396 17.3196

ans = 2×1

8.7473 17.6116

[Ayodimeji Ojelade]

Thank you! Do you know how I would be able to plot these on the x against k new on the y? I receive another error when I try due to the data format being a cell now?

[Torsten]

k1=180; k2=50; k3=220;
knew=linspace(k1*0.4,k1*1.6,20);
m1=1.1; m2=3.4;
for i=1:length(knew)  
    K{i}=[knew(i)+k2,-k2;-k2,k2+k3];
    M{i}=[m1,0;0,m2];
    lambda{i}=eig(double(K{i}),double(M{i})); 
    omega_nf{i}=sqrt(lambda{i});
end 
plot(cell2mat(omega_nf),knew)
grid on

If you don't need K, M and lambda in further calculations, you can also do

k1=180; k2=50; k3=220; n = 20;
knew=linspace(k1*0.4,k1*1.6,n);
m1=1.1; m2=3.4;
omega_nf = zeros(2,n);
for i=1:n  
    K=[knew(i)+k2,-k2;-k2,k2+k3];
    M=[m1,0;0,m2];
    lambda=eig(K,M); 
    omega_nf(:,i)=sqrt(lambda);
end 
plot(omega_nf,knew)
grid on