sth wrong in my matlab code..

hi..
im writing a code to design a multilayer optical filter, the code goes like this:
i have N layers where each of them is described using a characteristic matrix m, and the resulting matrix for the whole structure is M=Πm from the first layer to the last one..

i wrote the code but theres sth. wrong it keeps telling me wrong using vertcat !!

can anyone take a look at it and tell me what is the prob. 'coz i can't find it..


and one more thing: how can i change the extension of a matlab file .m ??


*********************************************

for w=w %w=1000:2000 wavelength
M=[1 0;01];
d= ones(1,Nmax)*wc/4; %d:thickness of layer
%n layers each defined by m
for i=1:Nmax
if mod (i,2)==0
ni=nH;
else
ni=nL;
end

g=(2*pi*ni*d1i)/w; %M: the charactarestic matrix of all
%g=phase layers = multiplication of
m for each layer
m11=cos(g);
m12=(sin(g))/ni;
m21=ni*sin(g);
m22=cos(g);
M=M*[m11 i*m12;m21 m22];
end
t=2*n0/(((M(1)+i*M(3)*ns)*n0)+(i*M(2)+M(4)*ns));
%t=fractional transmission

tstar=conj(t);
T=t.*tstar.*(ns/n0);
R=1-T;
end
plot(R)
axis([wmin wmax 0 1])

you have typing problem on the second line:

M=[1 0;01];

should be

M=[1 0;0 1];

you forgot space between '0' and '1'. so the matlab thoth it was only one number.

hi..thanx , i didnt notcie that..

one more thing can u tell me how i can get R as a matrix in the big for loop, i cant get the whole results of the loop, it gives me the last one only

Added after 4 hours 10 minutes:

so, i did something in my code and it run perfectly, when i tried to run after 3 hours its not working and again i cant find what is wrong....


n0=1
ns=3
w=1000:2000
wc=1500
nL=2
nH=2.5
Nmax=3

for w=w
R(w)=R(w);
M=[1 0;0 1];
d= ones(1,Nmax)*wc/4; %d thickness of layers

for i=1:Nmax
if mod (i,2)==0
ni=nH;
else
ni=nL;
end

g=(2*pi*ni*d(1,i))/w
%g=phase
m11=cos(g);
m12=(sin(g))/ni;
m21=ni*sin(g);
m22=cos(g);
M=M*[m11 i*m12;i*m21 m22];
end
t=2*n0/(((M(1)+i*M(3)*ns)*n0)+(i*M(2)+M(4)*ns));
%t=fractional transmission
tstar=conj(t);
T=t.*tstar.*(ns/n0);
R(w)=1-T;

end

w=[wmin:wmax];
plot(w,R(w))

what should R store?

what the following line means: R(w)=R(w);

R should store the result of T-1
that is R=R(w)

about R(w)=R(w) i wrote this so it keeps giving me the new vales of R(w) in the end of the loop

maybe you mean this:

n0=1
ns=3
w=1000:2000
wc=1500
nL=2
nH=2.5
Nmax=3
R=[];

for w=w
%R(w)=R(w);
M=[1 0;0 1];
d= ones(1,Nmax)*wc/4; %d thickness of layers

for i=1:Nmax
if mod (i,2)==0
ni=nH;
else
ni=nL;
end

g=(2*pi*ni*d(1,i))/w
%g=phase
m11=cos(g);
m12=(sin(g))/ni;
m21=ni*sin(g);
m22=cos(g);
M=M*[m11 i*m12;i*m21 m22];
end
t=2*n0/(((M(1)+i*M(3)*ns)*n0)+(i*M(2)+M(4)*ns));
%t=fractional transmission
tstar=conj(t);
T=t.*tstar.*(ns/n0);
R=[R 1-T];

end

%w=[wmin:wmax];
%plot(w,R)
plot(R)