Hello, I am new and trying to plot the imaginary parts of a function, can anyone help?

Hello, I am trying to plot the imaginary parts of Kz against Kx from the equation:-

Kz^2 = 8c sin^2(DKx/2)[2c sin^2(DKx/2) - lambdaq0^2]

which i have written as

Kz = sqrt ( 8 .* c .* ( sin ( ( D .* Kx ) ./ 2 ) ) .^2 .* ( 2 .* c .* ( ( sin ( ( D .* Kx) ./ 2 ) ) .^2 ) - ( lambda .* ( q0.^2 ) ) ) )

where lambda, D, q0 and c are all constants.

and really, I have no idea where to start, can anyone help me?

Answer 1

[Orion]

Hi,

all the functions you need are here

Answer 2

[Chris]

Hello, thanks for the quick reply. Let us assume that I am completely inept at using matlab and my code looks like this:-

"clear variables

Kx = linspace(0,6*pi,300); D = 2.6 * 10^-9; lambda = 0.5 ; c = 0.5; q0 = 0.01 ;

Kz = sqrt ( 8 .* c .* ( sin ( ( D .* Kx ) ./ 2 ) ) .^2 .* ( 2 .* c .* ( ( sin ( ( D .* Kx) ./ 2 ) ) .^2 ) - ( lambda .* ( q0.^2 ) ) ) );

imag_Kz = imag(Kz);

figure (1) plot (Kx, imag_Kz)"

Does much of this seem wrong?

[Orion]

Your code is fine.

you really are plotting the imaginary part of Kz against Kx.

Note : when you post some code here, use the button {}Code to format it and make it more readable.