input arguments must be double?help

 clc;clear all;
 g_db=[0:1:10];

 g=10.^(g_db/10);
 %g=0:1:3;
 c=1;
 alpha=2;
 syms y
 a=sqrt(2.*(g).*(1-sqrt(1/2)));
 b=sqrt(2.*(g).*(1+sqrt(1/2)));
 m=exp(-0.5*(a.^2+b.^2).*y);
 r=marcumq((a.*sqrt(y)),(b.*sqrt(y)),1);
 x=((y.^(alpha-1)).*exp(-y./c))/((gamma(alpha))*(c^alpha));
 q=(m.*r);
 t=0.5*besseli(0,a.*b.*y).*m;
 s=(q-t).*x;
 P=int(s,y,0,100)
 semilogy(g_db,P,'o')
 hold on

Answer 1

[Steven Lord]

First, please format your code and display one command per line, to make it easier to read and recognize where one statement ends and another begins.

Second, give the FULL text of the error message and indicate (through a comment) the exact line of code on which you receive that error.

Third, I don't believe that the MARCUMQ functions from either Signal Processing Toolbox or Communications System Toolbox support symbolic input arguments. You will need to create a function that evaluates your integrand numerically and use that function with INTEGRAL not INT.