Error: Function definitions are not permitted in this context.

I want to design raised cosine pulse modulation code but this error keep coming up.

 function result = rcp(alpha, t, W)
 ↑
Error: Function definitions are not permitted in this context.

My source code:

 %rcp.m
 function result = rcp(alpha, t, W)
 %Raised cosine function in time domain
 result = sinc(2*W*t).*cos(2*pi* alpha*W*t)./(1-16*alpha^2*W^2*t.^2);
 %Command line
 t=[-3:0.001:3];
 plot(t,rcp(0.9999,t,1)) %alpha =  1, W = 1
 hold on;
 plot(t,rcp(0.5,t,1), '--r') %alpha = 0.5, W = 1
 plot(t,rcp(0.25,t,1),  ':') %alpha = 0.25, W = 1
 legend('₩alpha=1','₩alpha=0.5','₩alpha=0.25')
 ylabel('pulse amplitude')
 xlabel('t/T')
 axis([-3 3 -0.25 1])
 grid on
 title('Raised-cosine pulses in time domain')

Answer 1

[Star Strider]

Save your function ‘rcp’ to its own ‘.m’ file as ‘rcp.m’ in your MATLAB user path.

function result = rcp(alpha, t, W)
%Raised cosine function in time domain
result = sinc(2*W*t).*cos(2*pi* alpha*W*t)./(1-16*alpha^2*W^2*t.^2);
end

(Another option is to create a function with your main code, since function definitions are permitted within other functions. The terminating end call is necessary in that instance.)