programming to meet the hysteresis cycle of a permanent magnet dc motor in FEMM / MATLAB

hello everyone and thank you for reading my questions, here is my problem I want to plot the hysteresis curve of the stator (permanent magnet Alnico) B (H), but before you do it I must be sure that I have all defined , such materials (cylinder head, induced gap ....) is that I have the magnet? I made modeled in a DC machine with permanent magnet. and also how my excite armature which is wound a winding, and with a current density J. ie I will stir up my rotor from 0 to Jmax and then I converted it to get Hexc J and then the total H and I and the B notes, then I will have the first magnetization curve and then I back to jmax I 0 and observes the H and B (for the full cycle) but how all this? is what I should do a loop? how? thank you and I await your response and help. in fact I have write a program FEMM under matlab environment. thank you!