Matrix dimensions must agree.

Can you please guide me the error of the line

Matrix dimensions must agree.

Error in Exercise1 (line 75)

eps_real = 1./(1 - (1 - (Cs1./Cs2)).*(t_gap/t_mut));

[Tommy]

It would help if you could provide the values of Cs1, Cs2, t_gap, and t_mut, or at least the dimensions of each.

[Rincy Kunjumon]

The below is my MATLAB code

%%% Given Values %%%

eps0 = 8.854*10^(-12); %%permittivity of free space

d_A = 38*10^(-3); %%Electrode A diameter

d_B = 5*10^(-3); %%Electrode B diameter

Condition = 3 %% 1-contact method , 2-contact method with thin gold electrodes, 3-non-contact method

d_mut = 54.11*10^(-3); %%Average diameter of the specimen

t_mut = 5*10^(-3); %%Average thickness of the specimen

t_gap = 0; %% only for condition c,non-contact method

filename = 'sample3.txt'; %% for condition -3, file without mut inserted

delimiterIn = '\t';

headerlinesIn = 1;

filename2 = 'sample2.txt'; %% Only used for method 3,with mut inserted

delimiterIn2 = '\t';

headerlinesIn2 = 1;

%%Complex Permittivity calculation%%%%

if Condition == 1

A = importdata(filename,delimiterIn,headerlinesIn);

f = A.data(:,1);

Cp =A.data(:,2);

D = A.data(:,3);

if d_mut < d_A

d = d_B;

else

d = d_A;

end

eps_real = (Cp.*t_mut)/( pi*((d/2).^2).*eps0); %%Real part of complex permittivity

eps_imaginary = -(eps_real.*D); %% D = tandelta ,also the equation = (eps_real.*tandelta)

elseif Condition == 2

A = importdata(filename,delimiterIn,headerlinesIn);

f = A.data(:,1);

Cp =A.data(:,2);

D = A.data(:,3);

d = d_mut;

eps_real = (Cp.*t_mut)/( pi*((d/2).^2).*eps0); %%Real part of complex permittivity

eps_imaginary = -(eps_real.*D); %% D = tandelta ,also the equation = (eps_real.*tandelta)

else %%%%%Condition - 3

A = importdata(filename,delimiterIn,headerlinesIn);

f = A.data(:,1);

Cs1 =A.data(:,2);

D1 = A.data(:,3);

B = importdata(filename2,delimiterIn,headerlinesIn);

f = B.data(:,1);

Cs2 =B.data(:,2);

D2 = B.data(:,3);

if d_mut < d_A

d = d_B;

else

d = d_A;

end

eps_real = 1 ./(1 - (1 - (Cs1./Cs2)).*(t_gap ./t_mut)); %%Cs1-Capacitance without MUT inserted: Cs2-Capacitance with MUT inserted

tandelta = D2 + eps_real.*(D2 - D1).*((t_gap./t_mut) - 1); %%D1-Dissipation factor without MUT inserted: D2-Dissipation factor with MUT inserted

eps_imaginary = -(eps_real.*tandelta);

end

%%%% Graph - Plot %%%%

figure(1);

semilogx(f,eps_real,f,eps_imaginary);

title ('Relative Complex Permittivity');

xlabel ('Freq [Hz]');

legend ('real part' , 'imaginary part');

[darova]

I have an error here

Any suggestions?

[Tommy]

I would guess Cs1 and Cs2 are not the same size, considering that t_gap and t_mut are scalars, but it's hard to tell without being able to run the code. After you get the error, look in your workspace and see whether Cs1 and Cs2 are the same size.

[Rincy Kunjumon]

Ok thank you i got it