How can I define one variable of a 4-variable function, then compute the 3-dimensional integral?

I have a probability function that has four variables: (charge, x, y, z). I need to use this function for several atoms. I have tried to declare the charge, then integrate with integral3 for x,y, and z, but it hasn't worked.

Here is part of my code:

function h = int3d(a,x,y,z)
h = integral3(func,-x,x,-y,y,-z,z); 

%attempting to convert a 4-var function into a 3-var function
    function f = func(x1,x2,x3) 
        f = p(a,x1,x2,x3); %p accepts (charge, x1,x2,x3) and returns numeric answer
    end      
end

Does anybody have any suggestions? My project depends on being able to perform these integrals. I have searched online and tried for several hours to find a solution, but nothing has worked.

Answer 1

[Andrei Bobrov]

try:

h = integral3(@(x1,y1,z1)p(a,x1,x2,x3),-x,x,-y,y,-z,z);