The issue is caused by the code that adjusts the axes position. Comment that out, and your axes labels appear.
% CGLsim1D.m
% Copyright David M. Winterbottom 2005
% ************************************************************
% Simulating the complex Ginzburg-Landau equation in 1D using
% pseudo-spectral code and ETD2 exponential time-stepping (See
% Matthews and Cox, J. Comp. Phys., 176 430-455, 2002)
% ************************************************************
disp('*** 1D CGL SIMULATION ***');
% Set equation coefficients
a = -2;
b = 0.4;
% Set system parameters
L = 200; % Domain size
Tmax = 200; % Simulation time
N = 512; % Number of grid points
dT = 0.05; % Timestep (choose between 0.01 and 0.05)
dps = 1000; % Number of stored times
ic = 'pulse'; % Initial condition: choose 'zero', 'tw', 'uniform' or 'pulse'
n = 0; % Winding number for 'tw' initial condition
co = 0; % Whether to continue simulation from final values of previous
% Calculate some further parameters
nmax = round(Tmax/dT);
q = n*2*pi/L;
X = (L/N)*(-N/2:N/2-1)';
nplt = floor(nmax/dps);
% Define initial conditions
if co == 0
Tdata = zeros(1,dps+1);
if strcmp(ic, 'zero')
A = zeros(size(X)) + 10^(-2)*randn(size(X));
elseif strcmp(ic, 'tw')
A = sqrt(1-q^2)*exp(1i*q*X) + 10^(-2)*randn(size(X));
elseif strcmp(ic, 'uniform')
A = ones(size(X)) + 0.01*randn(size(X));
elseif strcmp(ic, 'pulse')
A = sech((X+10).^2) + 0.8*sech((X-30).^2) + 10^(-2)*randn(size(X));
else
error('invalid initial condition selected')
end
Tdata(1) = 0;
else
A = Adata(:,end);
starttime = Tdata(end);
Tdata = zeros(1,dps+1);
Tdata(1) = starttime;
disp(' CARRYING OVER...')
end
% Set wavenumbers and data arrays
k = [0:N/2-1 0 -N/2+1:-1]'*(2*pi/L);
k2 = k.*k; k2(N/2+1) = ((N/2)*(2*pi/L))^2;
Adata = zeros(N,dps+1);
A_hatdata = zeros(N,dps+1);
A_hat = fft(A);
Adata(:,1) = A;
A_hatdata(:,1) = A_hat;
% Compute exponentials and nonlinear factors for ETD2 method
cA = 1-k2*(1+1i*a);
expA = exp(dT*cA);
nlfacA = (exp(dT*cA).*(1+1./cA/dT)-1./cA/dT-2)./cA;
nlfacAp = (exp(dT*cA).*(-1./cA/dT)+1./cA/dT+1)./cA;
% Solve PDE
dataindex = 2;
for n = 1:nmax
T = Tdata(1) + n*dT;
A = ifft(A_hat);
% Find nonlinear component in Fourier space
nlA = -(1+1i*b)*fft(A.*abs(A).^2);
% Setting the first values of the previous nonlinear coefficients
if n == 1
nlAp = nlA;
end
% Time-stepping
A_hat = A_hat.*expA + nlfacA.*nlA + nlfacAp.*nlAp;
nlAp = nlA;
% Saving data
if mod(n,nplt) == 0
A = ifft(A_hat);
Adata(:,dataindex) = A;
A_hatdata(:,dataindex) = A_hat;
Tdata(dataindex) = T;
dataindex = dataindex + 1;
end
% Commenting on time elapsed
if mod(n,floor(nmax/10)) == 0
outp = strcat(' n= ', num2str(n), ' completed'); disp(outp);
end
end
% Plot evolution
figure('position', [200 200 300 350])
surf(X,Tdata,real(Adata).')
view(0,90), shading interp, axis tight
% set(gca,'position', [0 0 1 1]) <-------- Comment out
set(gca,...
'xcolor', [0.6 0.6 0.6],...
'ycolor', [0.6 0.6 0.6],...
'fontsize', 6,...
'fontname', 'courier')
xlabel('X',...
'fontname', 'courier',...
'fontsize', 6,...
'color', [0.6 0.6 0.6])
ylabel('T',...
'fontname', 'courier',...
'fontsize', 6,...
'color', [0.6 0.6 0.6],...
'rotation', 0)
title('evolution of |A|',...
'fontname', 'courier',...
'fontsize', 6,...
'color', [0.6 0.6 0.6])
