% see http://tools.crocus-technology.com:5010/MF_CAL
% note that a and b are reversed!

I = 20;
mu0 = 4e-7*pi;
a = 10e-3;
b = 2e-3;

Bx = @(x, y) mu0*I/(4*pi*a*b) * integral3(@(xs, ys, zs) -(y-ys)./(((x-xs).^2 + (y-ys).^2 + zs.^2).^(3/2)), -a/2, a/2, -b/2, b/2, -inf, inf, 'AbsTol',1e-3);
By = @(x, y) mu0*I/(4*pi*a*b) * integral3(@(xs, ys, zs) (x-xs)./(((x-xs).^2 + (y-ys).^2 + zs.^2).^(3/2)), -a/2, a/2, -b/2, b/2, -inf, inf,'AbsTol',1e-3);

B = @(x,y) [Bx(x,y); By(x,y)];

B(0, 11e-3)

% x = (-7:7)*1e-3;
% y = (-4:4)*1e-3;
% BB = [];
% 
% 
% for u=1:length(x)
%     for v=1:length(y)
%         BB = [BB [x(u); y(v); B(x(u),y(v))]];
%         
%         figure(1);
%         quiver(BB(1,:), BB(2,:), BB(3,:), BB(4,:));
%         drawnow
%     end
% end
%             
% figure(1);
% rectangle('Position', [-a/2 -b/2 a b])