how to make anonymous function and it's plot?

i want to make black body radiation

clear

close all

clc

%Black body radiation graph

R=@(wl,T) 2*pi*c^2*h./(wl.^5)./(exp(h*c./wl/k/T)-1);

h=6.626e-34;

c=3e8;

k=1.38e-23;

wl=0.1:0.1:3;

this is my code but they said c doesn't recognize what's the problem...?

Answer 1

[Star Strider]

Either include all of them as arguments:

R=@(wl,T,h,c,k) 2*pi*c^2*h./(wl.^5)./(exp(h*c./wl/k/T)-1);

h=6.626e-34;
c=3e8;
k=1.38e-23;
wl=1E-9:0.1:3;
T = 273;

figure
plot(wl,R(wl,T,h,c,k) )
grid

or define the ‘R’ function after assigning the constants:

%Black body radiation graph
h=6.626e-34;
c=3e8;
k=1.38e-23;

R=@(wl,T) 2*pi*c^2*h./(wl.^5)./(exp(h*c./wl/k/T)-1);

wl=1E-9:0.1:3;
T = 273;

figure
plot(wl,R(wl,T))
grid

Regardless, the constants must exist in your workspace before the ‘R’ function is called.

Both of these will work.