How to correct matrix dimension disagree error

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')

[David Hill]

What is 1i and 2i? You will need to make the size of n and the size of u the same. Can n be linspace(0,.18)?

[the cyclist]

1i and 2i are just the imaginary constants sqrt(-1) and 2*sqrt(-1), so should not be problematic here.

[Samuel Suakye]

I want to plot both the real part and the imaginary part separately

[Samuel Suakye]

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

Answer 1

[Image Analyst]

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';

[Image Analyst]

Or, with a single for loop:

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);
	sigma = ((1i.*u-1-v.^2)./(v.^2-u.^2 +1-2i.*u)).*(1./(v.^2 +1));
	sigmapri = thisN * ((1i.*u-1-v.^2)./((1+thisN).^2 +v.^2).*(v.^2-u.^2 +1-2i.*u)).*(1-(v./(v.^2 +1)));
	w = sigma + sigmapri;
	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';

[Samuel Suakye]

Thank you very much

[Samuel Suakye]

% 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]

Please help me solve this problem, it is a double summation and can't tell whether am right because for two days running and still no results. Thanks in advance

Answer 2

[the cyclist]

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?

[Samuel Suakye]

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