How to slice a 3D vector field(defined in spherical coordinates) scattered data?

I have the following code:

[r,theta,phi] = meshgrid(0:1:10,0:pi/10:pi, 0:pi/10:2*pi);
li=3;
mi=3;
b=10*mi*ksr(li,mi,theta).*BT(li,r);
x=r.*sin(theta).*cos(phi);
y=r.*sin(theta).*sin(phi);
z=r.*cos(theta);

b is a function that gives me values for each point in mesh grid.

After this when I call scatter3 function as below I get the below figure.

scatter3(x(:),y(:),z(:),[],f(:));

Now I wish to slice it using the slice function as below:

xslice =[1];
yslice = [];
zslice = [];
slice(x,y,z,b,xslice,yslice,zslice);

When I'm running this, I'm getting the following error:

Error using interp3 (line 148)
Input grid is not a valid MESHGRID.

Error in slice (line 104)
    vi = interp3(x,y,z,v,xi,yi,zi,method);

Error in wqp (line 12)
slice(x,y,z,b,xslice,yslice,zslice);

Can anyone please explain what's happening. Your help will be appreciated.