MATLAB: How to plot the log to base 10 of absolute value of a function containing Sigma (Σ)

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How can I do this plot in MATLAB?

Best Answer

Try this code, it might help.
clear all
close all
Nt = 100;
Nx = 150;
L  = 2;
a = .5;
t  = 0:4/(Nt-1):4;
x  = 0:L/(Nx-1):L;
[t,x] = meshgrid(t,x);
q = zeros(Nt,Nx);
M = 500;
for n = 1:M
    an = (2*n-1)/(2*L);
    bn = an*pi;
    cn = bn^2;
    An = (-1)^n/(1+a*cn);
    xn = exp(-cn*t/(1+a*cn));
    yn = sin(bn*x);
    q = q + An*yn'.*xn';
end
qabs = log10(abs(q));
surf(t',x',qabs)
colormap('winter')
xlabel('t');
ylabel('x');
zlabel('10log|q|')
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