Index in position 1 is invalid. Array indices must be positive integers or logical values.

Getting the error

Index in position 1 is invalid. Array indices must be positive integers or logical values.

Error in Untitled (line 35) plot(x, Tdata(0,:));

when running. Cannot figure out how to make the plot work in the following script.

b = 0.0003;

a = 1.5;

d = 5.3;

c = 1.8;

R = 2/100; %m

Tr = -45; %degC

Ti = -30; %degC

N = 10;

x = linspace(-R,R,(2*N+1));

dx = x(2)-x(1);

T = zeros(size(x));

T = T + Ti;

T(1) = Tr;

T(end) = Tr;

Tdata = T;

dt = 1.8;

T1 = T;

T2 = zeros(size(T1));

ndt = 1800/dt;

for j = 1:ndt

T2(1) = Tr;

T2(end) = Tr;

for i=2; length(T2)-1;

T2(i) = T1(i) + dt/2/dx/dx/(c+d*T1(i))*((2*a+b*(T1(i+1)+T1(i)))*(T1(i+1)-T1(i))-(2*a+b*(T1(i-1)+T1(i)))*(T1(i)-T1(i-1)));

end

Tdata = [Tdata;T2];

T1=T2;

end

plot(x, Tdata(0,:));

Answer 1

[Image Analyst]

The first row is not 0 -- it's 1. Try

plot(x, Tdata(1,:), 'b-', 'LineWidth', 2);

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