In accordance with the present invention, there is provided a method of profiling a total vector potential field of a periodic permanent magnetic field structure, wherein desired elements of the total vector potential field are known. The magnetic field structure comprises a plurality of magnets having individual vector potential fields which collectively form the total vector potential field. The method provides for using an electromagnetic solver to generate data files representative of each individual magnet's contribution to the total vector potential field. Such data files are generated by assuming a magnetization value of one unit for a selected magnet, setting magnetization values of zero for all other magnets, setting the electromagnetic solver to use high resolution proximate the selected magnet and to use low resolution elsewhere, using the electromagnetic solver to compute the individual vector potential fields for all space for which the total vector potential field is to be profiled, and repeating such steps for each magnet of the plurality of magnets to generate the data files. The method further provides for using the data files to determine magnetization values for each magnet necessary to provide the desired elements of the total vector potential field, and using the determined magnetization values to superimpose the individual vector potential fields to determine the total vector potential field.