I don't understand why This code doesn't work ----error

i want to solve this problem... here is my code...

This doesn't work saying "??? Undefined function or method 'power' for input arguments of type 'function_handle'."

please help me...

I have constant of R,th,C00 and so on

diC1=@(z) (((2*pi*e0)*((R^2)*(1-sin(th)))/((z)*(z)+R*sin(th))));

Call1=@(z) 2*pi*e0*R*log(1+R*(1-sin(th))/z)+C00;

Re1=@(z) ((diC1)*(j/(2*pi*f*(Call1).^2))*(yab/((1+yaa*Rs)*(1+ybb*ZL)-(yab)^2*Rs*ZL))...
  -yab*ZL*(ybb+yaa*ybb*Rs-yab^2*Rs)/((1+yaa*Rs)*(1+ybb*ZL)-yab^2*Rs*ZL)^2);%*(z(i)-z0);

z=0:0.1:10;

plot(z,Re1(z))

[Adam]

Using just 'j' and 'i' should work fine for complex numbers, but it is recommended to use 1j or 1i for complex numbers. This isn't related to your error, just a comment based on the discussion in Torsten's answer.

Answer 1

[Adam]

Your function handles take z as an argument so you need to pass this in and actually call the function

Re1=@(z) ((diC1)*(j/(2*pi*f*(Call1).^2))...

does not actually call your functions diC1 and Call1, it puts the function handle itself into the mathematical expression. This is why you get the error that power is not defined for function_handle inputs because you are trying to effectively do:

Call1.^2

and square the function handle.

You should replace this with:

Re1=@(z) ((diC1(z))*(j/(2*pi*f*(Call1(z)).^2))...

and the same for any other function handle calls that I missed. Even if the function handles don't take an argument you still need to use

diC1()

to actually execute the function because otherwise the function handle itself is a variable and can be passed around as such, but cannot be used in mathematical expressions without being actually called as above.

[Junho Ban]

Thanks for answering my question!!!

Answer 2

[Torsten]

diC1= (((2*pi.*e0).*((R.^2).*(1-sin(th)))./((z).*(z)+R.*sin(th))));
Call1= 2*pi.*e0.*R.*log(1+R.*(1-sin(th))./z)+C00;
Re1= ((diC1).*(j./(2*pi.*f.*(Call1).^2)).*(yab./((1+yaa.*Rs).*(1+ybb.*ZL)-(yab).^2.*Rs.*ZL))...
  -yab.*ZL.*(ybb+yaa.*ybb.*Rs-yab.^2.*Rs)/((1+yaa.*Rs).*(1+ybb.*ZL)-yab.^2.*Rs.*ZL).^2);%*(z(i)-z0);
z=0:0.1:10;

plot(z,Re1)

Of course, all variables you use have to be defined in advance.

Is "j" supposed to be the imaginary unit ?

Best wishes

Torsten.

[Junho Ban]

yes 'j' is the imaginary unit...and all variables are defined.

[Torsten]

Then you can only plot real and imaginary part of Re1 separately.

plot(z,imag(Re1))

e.g.

Best wishes

Torsten.

[Junho Ban]

thanks for your tip!!!!!!!!!!!!! :)