Array indices must be positive integers or 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';

Answer 1

[Sriram Tadavarty]

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

Answer 2

[Steven Lord]

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)));

You meant to multiply trig by the expression that follows it, not to use that expression to index into the (scalar) trig variable, right?