Histogram of the magnetic field components at the position with normalized coordinates r = (0, 0, 0.5) in the 3D domain for 100 different inverted models. The different panels correspond to the magnetic field vector component along the x, y, and z axes in the model, from top to bottom, respectively. The vertical red line indicates the true value of the magnetic field vector. The relative uncertainty for each component at this position, as defined in Eqs. (2) and (3), are U_x = 0.97, U_y = 0.50, U_z = 0.60, and U_xyz = 0.66.