# How to correct matrix dimension disagree error

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Samuel Suakye on 28 Mar 2020
Commented: Samuel Suakye on 16 Apr 2020
figure
clear;
clc;
v = 1.0;
n=[0.00 0.10 0.12 0.18];
u = linspace(0,2);
%%
for i = 1:length(n)
sigma = ((1i.*u-1-v.^2)./(v.^2-u.^2 +1-2i.*u)).*(1./(v.^2 +1));
sigmapri = n*((1i.*u-1-v.^2)./((1+n).^2 +v.^2).*(v.^2-u.^2 +1-2i.*u)).*(1-(v./(v.^2 +1)));
w = sigma + sigmapri;
plot(u, real(w))
end
%%
xlabel('\omega*\tau')
ylabel('\sigma(\omega)/\sigma_o')

Show 1 older comment
the cyclist on 28 Mar 2020
1i and 2i are just the imaginary constants sqrt(-1) and 2*sqrt(-1), so should not be problematic here.
Samuel Suakye on 28 Mar 2020
I want to plot both the real part and the imaginary part separately
Samuel Suakye on 28 Mar 2020
I want to plot a graph when n=0, n=0.10, n=0.12, n=0.18 using iteration on the same xy-plane

Image Analyst on 28 Mar 2020
I think you're looking for this:
hFig = figure
clc;
v = 1.0;
n=[0.00 0.10 0.12 0.18];
u = linspace(0,2, 30); % However many you want.
legendStrings = cell(length(n), 1);
for k1 = 1:length(n)
thisN = n(k1);
for k2 = 1 : length(u)
thisU = u(k2);
sigma = ((1i.*thisU-1-v.^2)./(v.^2-thisU.^2 +1-2i.*thisU)).*(1./(v.^2 +1));
sigmapri = thisN * ((1i.*thisU-1-v.^2)./((1+thisN).^2 +v.^2).*(v.^2-thisU.^2 +1-2i.*thisU)).*(1-(v./(v.^2 +1)));
w(k2) = sigma + sigmapri;
end
legendStrings{k1} = sprintf('n = %.2f', thisN);
plot(u, real(w), '.-', 'LineWidth', 2, 'MarkerSize', 15);
hold on;
drawnow;
end
grid on;
fontSize = 20;
xlabel('\omega*\tau', 'FontSize', fontSize)
ylabel('\sigma(\omega)/\sigma_o', 'FontSize', fontSize)
title('\sigma(\omega)/\sigma_o vs. \omega*\tau', 'FontSize', fontSize)
legend(legendStrings, 'Location', 'northwest');
% Maximize the figure window.
hFig.WindowState = 'maximized';

Show 1 older comment
Samuel Suakye on 28 Mar 2020
Thank you very much
Samuel Suakye on 16 Apr 2020
% A graph of j_z/j_o = j vrs beta1 (dimensionless amplitude)
% On 12-04-2020
hFig = figure
clc;
b = 0.142e-9; gammao = 3.0; m = 101;
hbar = 1; e = -1;
K = 8.617e-16; T = 287.5;
a = ((3*b)/(2*hbar)); Pz = ((2*pi*hbar)/(3*b));
beta2 = 1; beta1 = linspace(0,10, 30); % However many you want.
Wcnzz = sqrt(3);
jo = ((8*e*Wcnzz*gammao)/(3*hbar*m*b));
%%
syms q s
B1 = q.*beta1; B2 = q.*beta2; v = ((pi.*s)./m); h = (a.*Pz);
z = (2.*(pi.^2).*s.*sqrt(3).*(a./(2*pi)));
Eqszz = (a./(2*pi)).*((1+(4.*cos(h).*cos(v))+(4.*((cos(v)).^2))).^0.5);
Fqszz = ((a.^2).*m)./((z.*((1+(4.*cos(h).*cos(v))+(4.*((cos(v)).^2))).^0.5))./(K.*T));
J1 = besselj(0,B1); J2 = besselj(0,B2);
J = q.*Fqszz.*Eqszz.*J1.*J2;
X = symsum(J,s,1,m);
jz = symsum(X,q,1,inf);
j = jz./jo;
fplot(beta1, j, 'r-', 'LineWidth', 2 );
drawnow;
grid on;
fontSize = 20;
xlabel('\beta_1', 'FontSize', fontSize)
ylabel('j_z/j_o', 'FontSize', fontSize)
hold on
%%
b = 0.142e-9; gammao = 3.0; m = 101;
hbar = 1; e = -1;
K = 8.617e-16; T = 287.5;
a = ((3*b)/(2*hbar)); Pz = ((2*pi*hbar)/(3*b));
beta2 = 1; beta1 = linspace(0,10, 30); % However many you want.
Wcnac = 1; t = sqrt(3); n = 1e-9;
jo = ((8*e*Wcnac*gammao)/(3*hbar*m*b));
%%
syms q s
B1 = q.*beta1; B2 = q.*beta2; u = ((a.*Pz)./t); g = ((pi.*s.*t)./n);
y = (2.*(pi.^2).*s.*t);
Eqsac = ((1+(4.*cos(g).*cos(u))+(4.*((cos(u)).^2))).^0.5);
Fqsac = ((a.^2).*n)./((y.*((1+(4.*cos(g).*cos(u))+(4.*((cos(u)).^2))).^0.5))./(K.*T));
J1 = besselj(0,B1); J2 = besselj(0,B2);
J = q.*Fqsac.*Eqsac.*J1.*J2;
X1 = symsum(J,s,1,m);
jz = symsum(X1,q,1,inf);
j = jz./jo;
fplot(beta1, j, 'b-', 'LineWidth', 2);
drawnow;
grid on;
fontSize = 20;
xlabel('\beta_1', 'FontSize', fontSize)
ylabel('j_z/j_o', 'FontSize', fontSize)
title('j_x/j_o vs. \beta_1', 'FontSize', fontSize)
legend('zigzig CNs','armchair CNs','Location','Best');
% Maximize the figure window.
hFig.WindowState = 'maximized';
Samuel Suakye on 16 Apr 2020

the cyclist on 28 Mar 2020
You are effectively trying to do this operation in your code:
n * u
where n is a 1x4 matrix, and u is a 1x100 matrix.
That won't work, as either a matrix multiplication or as an element-by-element multiplication. What do you expect from that?

#### 1 Comment

Samuel Suakye on 28 Mar 2020
I want to plot a graph when n=0, n=0.10, n=0.12, n=0.18 using iteration on the same xy-plane