Example of Fig 4.13 - 4.14

Signal and Noise

function [F,a]=example41314
%
%  Eof of signal and noise
%


% Generate signal data

clf;

n=34;
m=20;

u=linspace(0,2*pi,m);
v=linspace(0,2*pi,n);

[x,y]=meshgrid(u);


for j = 1:n
     a(:,:,j) = 10*sin(x - 2*v(j)) + 10*randn(length(u));
   surf(x,y,a(:,:,j)) ; colormap(gray);brighten(0.5);
 if j == 10
     print('-dpdf','-painters','-adobecset',['example13a.pdf']);
 end

%  F(j) = getframe;
end
%movie(F);

for j = 1:n
    z(:,j) = reshape(a(:,:,j),[m*m 1]);
end

size(z)

[eof,s,v] = svd(z,0); size(eof), size(v)

plot(1:34,v(:,1),1:34,v(:,2))
return


lam=s.^2/sum(s.^2);


for j = 1:9
   subplot(3,3,j)
   contourf(reshape(eof(:,j),[ 20 20]));colormap(gray); brighten(0.5);
   title([' Eof ' num2str(j) '     ' num2str(lam(j)) '%'],'fontname','times')
end

orient tall;
print('-dpdf','-painters','-adobecset',['example13b.pdf']);

return
ans =

   400    34


ans =

   400    34


ans =

    34    34