You have a non-comment line before the function definition starts. Thus, Matlab thinks that this is a script. Make the first line a comment, and this problem should go away. Note that the code analyzer in the editor flags this issue with red squiggles under the function name and also flags some other issues with orange squiggles. You need to fix those as well. Specifically, you can't use == to compare a character vector. You either need to use a string scalar (with double quotes, if the Master parameter that you pass in is also a string scalar) or use the strcmp function.
GtDis2wL
%Created: 7/1/24
%Latest revision
function [wl,Deg] = GtDis2wL(Master,Dist,Peak)
if Master == '2135'
rExt=100;
alpha=2.627499; %deg
beta405=-32.0725; %deg
WL=6010; %nm
G=1197.9*10^-6; %g/nm
names=-1;
DistOfst=Peak-Dist;
DegOfst=atand(DistOfst/rExt);%deg
Deg=DegOfst+beta405;%deg
wl=(-1/G)*(sind(alpha)+sind(Deg));
else
print('Hello')
end
end
