Thread Subject: Matrix dimensions not agree, not rendering mesh. please help

Dear friends,

please have a look at the code that i have, there is some small problem here;

t=linspace(0,.00000001,200);
z=linspace(0,.0001,200);
s=[1,0,0,0,0,0,0,0,0];
[t,y]=ode45(@fname,t,s);
z1=i*21445.*y(:,3)*z-21445*(t-z);---------A
size(z1)
size(t)
size(z)
surf(z1,z,t);

i want to plot the equation A, i.e. z1 Vs Time vs Distance, but there is some dimension problem, i would be highly obliged for your help.

Thanks alot

Salman,

Could you also paste fname.m below? It is required by the piece of code you have written.

Best.

"Sadik " <sadik.hava@gmail.com> wrote in message <iq3vbc$93m$1@newscl01ah.mathworks.com>...
> Salman,
>
> Could you also paste fname.m below? It is required by the piece of code you have written.
>
> Best.

Yes sure!

here is the fname code;

dydt(1)=-k1*y(3)+k1*y(7)+k5*y(9);
dydt(5)=-k2*y(6)+k2*y(8);
dydt(9)=k1*y(3)+k2*y(6)-k1*y(7)-k2*y(8)-k5*y(9);
dydt(2)=-k3*y(2)-k2*y(3)+k1*y(8);
dydt(3)=-k1*y(1)-k2*y(2)-k4*y(3)+k1*y(9);
dydt(4)=-k3*y(4)-k1*y(6)+k2*y(7);
dydt(6)=-k1*y(4)-k2*y(5)+k2*y(9)-k6*y(6);%
dydt(7)=k1*y(1)+k2*y(4)-k4*y(7)-k1*y(9);
dydt(8)=k1*y(2)+k2*y(5)-k6*y(8);%-----

thank you very much!

Hi Salman,

Actually you should copy and paste EVERYTHING in the file. You should have

k1 = ...
k2 = ...

type of lines in fname.m.

Best.

"Sadik " <sadik.hava@gmail.com> wrote in message <iq4r9o$7v7$1@newscl01ah.mathworks.com>...
> Hi Salman,
>
> Actually you should copy and paste EVERYTHING in the file. You should have
>
> k1 = ...
> k2 = ...
>
> type of lines in fname.m.
>
> Best.

Here it is,

k5=1000000000;%Excited state optical decay,1000 MHz
k2=10*i*k5/2; %Rabi frequency of the coupling beam
k1=k2/10; %Rabi freq of the probe beam
k3=0; %Spin decay between the lower states (Ground states)
k4=k5/2; %Decay rate between the ground and excited state, i.e. small Gamma ab
k6=k4; %decay between the metastable and excited state
%----------------------------------------------------------------%
dydt(1)=-k1*y(3)+k1*y(7)+k5*y(9);%Pop of the ground state
dydt(5)=-k2*y(6)+k2*y(8);%Pop of the metastable state
dydt(9)=k1*y(3)+k2*y(6)-k1*y(7)-k2*y(8)-k5*y(9);%Pop of the excited state
dydt(2)=-k3*y(2)-k2*y(3)+k1*y(8);%Ground states coherence
dydt(3)=-k1*y(1)-k2*y(2)-k4*y(3)+k1*y(9);%Spin coherence
dydt(4)=-k3*y(4)-k1*y(6)+k2*y(7);
dydt(6)=-k1*y(4)-k2*y(5)+k2*y(9)-k6*y(6);%----------
dydt(7)=k1*y(1)+k2*y(4)-k4*y(7)-k1*y(9);
dydt(8)=k1*y(2)+k2*y(5)-k6*y(8);%-------------------


thank you very much,

Hi Salman,

The problem is with the usage of surf. If you want to make a plot of Z1 vs. Z and T, then Z1 should be the third argument.

Here is an example that works, but you will need to modify it if it is not doing what you want theoretically.

t=linspace(0,.00000001,200);
z=linspace(0,.0001,200);
s=[1,0,0,0,0,0,0,0,0];
[t,y]=ode45(@fname,t,s);
[T,Z] = meshgrid(t,z);
Z1=i*21445.*repmat(y(:,3),[1 size(Z,2)]).*Z-21445*(T-Z);
surf(T,Z,abs(Z1))

Best.

"Sadik " <sadik.hava@gmail.com> wrote in message <iq5094$i6c$1@newscl01ah.mathworks.com>...
> Hi Salman,
>
> The problem is with the usage of surf. If you want to make a plot of Z1 vs. Z and T, then Z1 should be the third argument.
>
> Here is an example that works, but you will need to modify it if it is not doing what you want theoretically.
>
> t=linspace(0,.00000001,200);
> z=linspace(0,.0001,200);
> s=[1,0,0,0,0,0,0,0,0];
> [t,y]=ode45(@fname,t,s);
> [T,Z] = meshgrid(t,z);
> Z1=i*21445.*repmat(y(:,3),[1 size(Z,2)]).*Z-21445*(T-Z);
> surf(T,Z,abs(Z1))
>
> Best.


Thank you very much Dear Sadiq,

actually i did it this way, if you would please kindly take a look,

function maxbloch % all the simulation is done for the case of zero probe detuning
t=linspace(0,.00000001,200);
z=linspace(0,.0001,200);
s=[1,0,0,0,0,0,0,0,0];
[t,y]=ode45(@salman3,t,s);
f=repmat(t,1,200);
z1=i*(-2140967)*y(:,3)*z;
g=repmat(z,200,1);
k=z1-23567*(g-z1/34);%the large number is the constant of integration that i have chosen randomly.
surf(t,z,abs(k));

isn't this also correct?

I am thankful for your precious time.