Problem using quiver function to plot magnetic field outside of a circular loop

Hey guys, I'm having trouble getting the quiver function to display the magnetic field in the xz-plane outside of a circular loop of current.

Here are the functions I'm using to calculate and collate the field's component vectors at every point. I think these are working properly. The variable max is used to set the number of gridsteps.

function [ bx,by,bz ] = calcfield( max,x,y,z )

%Calculates the field inside a Helmholtz coil

    radius = .5;
    dtheta = 2*pi/20;
    bx = 0;
    by = 0;
    bz = 0;
    for theta = 0:dtheta:2*pi-dtheta
        dlx = -radius*dtheta*sin(theta);
        dly = radius*dtheta*cos(theta);
        rx = x - radius*cos(theta);
        ry = y - radius*sin(theta);
        rz = z;
        r = sqrt(rx^2+ry^2+rz^2);
        if r > 1/max % avoids wire
            bx = bx + dly * rz/(r^3);
            by = by - dlx * rz/(r^3);
            bz = bz + (dlx*ry-dly*rx)/(r^3);
        end
    end

end

function [ field ] = findfield( max )

%Finds the field in the x-z plane

    A = [1:2*max+1];
    D = [1:2*max+1];
    field = cat(3,A,D);
    for i = 1:2*max+1
         for k = 1:2*max+1
            [bx,by,bz]=calcfield(max,(i-max-1)/(max),0,(k-max-1)/(max));
            field(1,i,k) = bx;
            field(2,i,k) = by; 
            field(3,i,k) = bz;
         end
    end
end

Now, this will give us the field between -1 and 1 in both the x and z directions. If we use max = 20 and then use the squeeze function, we can get the vector components as arrays mapped to coordinates.

EDU>> field = findfield(20);

EDU>> Bx = squeeze(field(1,:,:));

EDU>> Bz = squeeze(field(3,:,:));

Now we need some arrays of coordinates to match these.

EDU>> x = linspace(-1,1,41);

EDU>> z = linspace(-1,1,41)';

The position 0 will be the 21st element for each of these.

On the z-axis, the Bz component will be the only contributor and should always be positive. We can check this latter part easily.

EDU>> Bz(21,:)

ans =

Columns 1 through 7

    1.1240    1.2696    1.4393    1.6379    1.8708    2.1448    2.4676

Columns 8 through 14

    2.8483    3.2970    3.8249    4.4429    5.1605    5.9833    6.9092

Columns 15 through 21

    7.9232    8.9918   10.0583   11.0426   11.8484   12.3802   12.5664

Columns 22 through 28

   12.3802   11.8484   11.0426   10.0583    8.9918    7.9232    6.9092

Columns 29 through 35

    5.9833    5.1605    4.4429    3.8249    3.2970    2.8483    2.4676

Columns 36 through 41

    2.1448    1.8708    1.6379    1.4393    1.2696    1.1240

Good! We also see that it's greatest at the origin (center of the loop) and decreases with distance.

So now I want to plot this, so I use quiver(x,z,Bx,Bz), and get a graph that shows the magnetic field immediately increase in magnitude and change direction at (0,.5) and (0,-.5). Obviously, I'm misusing the quiver function in some way, but I have no idea what to do. Any help would be most appreciated. (Note: I have also input the coordinates using the meshgrid function and gotten the same result.)