Double integration using dblquad not working

what is the mistake in this code, I'm getting this error "Error using dblquad>innerintegral (line 76)

Inputs must be floats, namely single or double."

SNRdB = 1;

SNR=10.^(SNRdB./10);

sigma=1./SNR;

sigma_1=(sqrt(3./4)).*sigma;

sigma_2=(sqrt(1./4)).*sigma;

syms mu_x sigma_x s dot_s

f_x=(1./(2*pi*(sigma_x).^2)).*exp(-(s-mu_x).^2./(2.*(sigma_x).^2))

f_s_1=subs(f_x,[mu_x,sigma_x],[dot_s,sigma_1])

f_dot_s=subs(f_x, [mu_x,sigma_x],[0,1]);

Pr=erf(s./(s.*sigma_2))*f_s_1*f_dot_s

Fun=@(x,y)subs(Pr,[s,dot_s],[x,y])

Pr_pos_c = dblquad(@(x,y)Fun(x,y),-inf,inf,0,inf)

Answer 1

[Steven Lord]

The function you pass into dblquad must return a double or single value. It cannot return a sym object. To compute a double integral using sym objects, call int twice. Alternately if you want to use dblquad (or the integral2 function, which is the recommended replacement for dblquad) convert your symbolic expression into a function handle using matlabFunction or call double on the results of the subs call inside your Fun function.

Fun=@(x,y)double(subs(Pr,[s,dot_s],[x,y]))

[Diana]

so you mean that after this Fun=@(x,y)double(subs(Pr,[s,dot_s],[x,y])), I can integrat using integral2 directly?

[Diana]

I tried to replace Fun=@(x,y)subs(Pr,[s,dot_s],[x,y]) with Fun=@(x,y)double(subs(Pr,[s,dot_s],[x,y])) and I got this eror

Error using sym/subs>normalize (line 205)

The lengths of the second and third arguments are inconsistent.

[Diana]

Note also that if I used =int(int(Pr,[-inf inf]),[0 inf]) instead of Pr_pos_c = dblquad(@(x,y)Fun(x,y),-inf,inf,0,inf), I don't get an error but I get this as an answer

int(int((1125899906842624*exp(-s^2/2)*exp(-(2535301200456458802993406410752*(dot_s - s)^2)/2399500369346179911436460901961)*(erf((2251799813685248*s)/1788668170957069)/2 + 1/2))/(1549032074989469*pi), s, -Inf, Inf), dot_s, 0, Inf)

but I don't get a finite number