MATLAB: Array indices must be positive integers or logical values.

logical values

hFig = figure

clc;

v = 2.0;u = 2.0;

K = 8.617e-5;

trig = sin(4)*cos(4);

p = 2.7; t = 2.0; e = 1.6022e-19;

deltag = 0.0156; deltaxi = 0.0204;

n=[0.00 0.20 0.50 1.00];

T = linspace(0,700, 30); % However many you want.

delta1 = deltag./(K.*T); delta2 = deltaxi./(K.*T);

B0xi = besseli(0,delta2); B1xi = besseli(1, delta2);

B0g = besseli(0, delta1); B1g = besseli(1, delta1);

q = ((K^2).*T)./(e^2); g = p./(K.*T);

a = (B0g./B1g)- (2./delta1);

b = (1 – ((3./delta1).*(B0g./B1g)) + 6./(delta1.^2));

c = (1 – ((B1xi./B0xi).*(1./delta2)));

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.*t)).^2 +v.^2).*(v.^2-u.^2 +1-2i.*u)).*(((B0g./B1g).*exp(0.9i.*pi))-(v./(v.^2 +1)));

w = sigma + sigmapri;

m = (w.*q.*trig((g.^2)-(2.*delta1.*g.*a)-(2.*delta2.*g.*(B1xi./B0xi))+((delta1.^2).*b)+(delta1.*delta2.*a.*(B1xi./B0xi))+((delta2.^2).*c)));

legendStrings{k1} = sprintf('n = %.2f', thisN);

plot(T, real(m), '.-', 'LineWidth', 2, 'MarkerSize', 15);

hold on;

drawnow;

end

grid on;

fontSize = 20;

xlabel('T(K)', 'FontSize', fontSize)

ylabel('\chi_\gamma', 'FontSize', fontSize)

title('\chi_\gamma vs. Temp(K)', 'FontSize', fontSize)

legend(legendStrings, 'Location', 'northeast');

% Maximize the figure window.

hFig.WindowState = 'maximized';

Best Answer

Hi Samuel,

In the calculation of m in the for loop, trig value is not multiplied instead accessed with a value. This is the source of the error. Update that line of code as below:

m = (w.*q.*trig.*((g.^2)-(2.*delta1.*g.*a)-(2.*delta2.*g.*(B1xi./B0xi))+((delta1.^2).*b)+(delta1.*delta2.*a.*(B1xi./B0xi))+((delta2.^2).*c)));

Hope this helps.

Regards,

Sriram

Related Solutions

MATLAB: Vectors must be the same length

[mu] = meshgrid(-10000:100:10000);

mu is now a 201 x 201 array.

J1 = besselj(mu,B1);

mu is 201 x 201 so J1 is 201 x 201.

J = (J1.^2);

J is the same size as J1, 201 x 201.

J(i) = jog.*sum(tmp(:));

one of the first 30 linear-indexed elements of J is replaced, leaving it 201 x 201.

plot(Betag, real(J), '.-', 'LineWidth', 2, 'MarkerSize', 15);

You plot the vector of length 30 against the 201 x 201 array.

I suggest

for i = 1:length(Betag)
        B1 = Betag(i);    
        J1 = besselj(mu,B1) .^ 2;
        R = (v + (mu.*u));
        S = ((v + (mu.*u)).^2);
        Z = (1+thisN.*((I2.*exp(1i.*mu.*p))+1)).*trig;
        tmp = ((J1.*R)./(1+(2.*thisN)+(thisN.^2)+S)).*Z;
        J(i) = jog.*sum(tmp(:));
end

MATLAB: How to correct matrix dimension disagree error

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';

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