How can i add multiple lines in a plot with a variable?

The code that i have is working as intented, but i want to add multiple lines in the same plot where the difference is one variable.

It is the variable "T" that is 5780, but i also want to have it plotted as T=4000, T=3500, T=3000, T=2500 & T=2000, all in the same picture.

Thanks in advance.

T=5780;
x(1)=1.0e-7;
I(1)=0;
I0=3.74177152e-16;
C=1.438776950e-2

for j=2:1000
    I(j-1)=I0*(x(j-1)^(-5))/(exp(C/(x(j-1)*T))-1);
    I(j-1)=I(j-1)/1.0e9;
    I(j-1)=I(j-1)/1.0e4;
    x(j)=x(j-1)+2.0e-9;
    x(j-1)=x(j-1)*1.0e9;
end
I(1000)=I0*(x(1000)^(-5))/(exp(C/(x(1000)*T))-1);
I(1000)=I(1000)/1.0e9;
I(1000)=I(1000)/1.0e4;
x(1000)=x(1000)*1.0e9;

plot(x,I);
xlabel('-> golflengte (nm)')
str = '$$ -> \Delta I \Delta \lambda^{-1} (10^4 Wm^2nm^{-1})$$';
ylabel(str,'Interpreter','latex')
axis([0 2500 0 10]);

Answer 1

[Walter Roberson]

T = [2000, 2500, 3000, 3500, 4000, 4500, 5000, 5780];
numT = length(T);

x(1)=1.0e-7;
I(1,1:numT) = 0;
I0=3.74177152e-16;
C=1.438776950e-2

C = 0.0144

for j=2:1000
    I(j-1,:) = I0*(x(j-1)^(-5))./(exp(C./(x(j-1)*T))-1);
    I(j-1,:) = I(j-1,:)/1.0e9;
    I(j-1,:) = I(j-1,:)/1.0e4;
    x(j)=x(j-1)+2.0e-9;
    x(j-1)=x(j-1)*1.0e9;
end
I(1000,:) = I0*(x(1000)^(-5))./(exp(C./(x(1000)*T))-1);
I(1000,:) = I(1000,:)/1.0e9;
I(1000,:) = I(1000,:)/1.0e4;
x(1000)=x(1000)*1.0e9;

plot(x,I);
xlabel('-> golflengte (nm)')
str = '$$ -> \Delta I \Delta \lambda^{-1} (10^4 Wm^2nm^{-1})$$';
ylabel(str,'Interpreter','latex')
axis([0 2500 0 10]);
legend(string(T))

[Promu]

Fast and correct! Many thanks!

[Promu]

Cheered a bit to soon, i'm getting this error? Any ideas?

[Walter Roberson]

Perhaps you did not clear I between the old code and the new code.

[Promu]

Just tried a new file and i am still getting the same error. Do i need to remove some temp file or something? The code and plot you posted is exactly what i mean.

[Walter Roberson]

clearvars

once before you run the code. I think you have an old I variable in memory.

The output you see above is "live" -- I ran it right in the Answers system itself.

[Promu]

That did the trick! Again, thank you very much!