3D Ray Intersecting a 3D Sphere

Hi,

I am a little stumped, I am trying to create a 3D sphere and have a 3D ray to pass through it.

I currently have 3 pieces of code, the first being the 3D sphere code shown below:

clc
%clear the screen%
clear

%Create a 3 by 1 Matrix with x, y and z co-ordinates equaling the sphere
[x y z] = sphere;
%creating a new variable called a with a 4 by 1 array showing its x, y, z
%position and its radius%
a=[3 3 3 3]

s1=surf(x*a(1,4)+a(1,1),y*a(1,4)+a(1,2),z*a(1,4)+a(1,3));

%setting the axis data of the viewport to 1, 1, 1%
daspect([1 1 1])
%Setting the viewers orientation of the axis%
view(30,10)
end

The second code is the 3D ray:

function [ output_args ] = Raycast( input_args )
%RAYCAST Summary of this function goes here
%   Detailed explanation goes here
% two points
P1 = [0,0,0];
P2 = [13,-11,19];

% vertial concatenation
pts = [P1; P2];

% use plot3:
plot3(pts(:,1), pts(:,2), pts(:,3))

end

I am trying to get them both in the same document but when I try it will either only show the sphere or show nothing it doesn't seem to work together, what am I doing wrong?, the whole code is below:

function [ output_args ] = Sphere( input_args )
%SPHERE Summary of this function goes here
%   Detailed explanation goes here
clc
%clear the screen%
clear

%Create a 3 by 1 Matrix with x, y and z co-ordinates equaling the sphere
[x y z] = sphere;
%creating a new variable called a with a 4 by 1 array showing its x, y, z
%position and its radius%
a=[3 3 3 3]

s1=surf(x*a(1,4)+a(1,1),y*a(1,4)+a(1,2),z*a(1,4)+a(1,3));

%setting the axis data of the viewport to 1, 1, 1%
daspect([1 1 1])
%Setting the viewers orientation of the axis%
view(30,10)

% two points
P1 = [0,0,0];
P2 = [13,-11,19];

% vertial concatenation
pts = [P1; P2];

% use plot3:
plot3(pts(:,1), pts(:,2), pts(:,3))
end