Thanks for your responses. sorry for my delayed answer as I was traveling internationally.nTruth, HFSS can simulate some magnetostatic modes, but you can not be sure it is correct because surface pinning condition is not known to users.nYes, I realize the limitations of HFSS regarding pinning and modes, but in certain regimes the magnetostatic approximation is still good, and that's what I'm interested in.nP.S. Use scripting to generate multiple materials and component objects. Every object is assigned a material from library uniformly.nThis was another option I considered, however, entering an analytical expression is so much simpler and cleaner (much fewer objects to deal with and less time to make changes). My original question was specifically regarding analytically defining spatially varying materials.nDo it as in times of Adam, Suhl, and Damon: cut the spin-guide at 45 degrees so the mode is converted A) to another mode type B) to lossy mode type, depending on magnetization of course, and put lossy material around that place.nWhen you say cut the spin guide at 45 degrees, do you mean cut the film width at 45 degrees (taper)? A simple drawing might help. Do you have a journal article on the topic?nX Y Z are not the same as $-project variables. You can not put them in project variable formulation. But you can use them in material editor.nThanks for the link. I had found that previously. I understand X Y and Z variables to be the intrinsic HFSS variables for position, which I have used to define project variables. What do you mean I can't put them in project variable formulation but only in the material editor? What if I choose to have a complicated expression which would be cleaner if entered as a project variable and referenced in the material editor?.I wonder how you define the input impedance of the magnetostatic wave. If you have a coplanar transducer, it is also not the best structure to find an equivalent load impedance because of complex modal composition. Why don't you use simple thin-wire as in classic works?nIf that's a practical model, i would model the whole transducer(antenna) and sweep its width until best matching, which will equalize the input impedance with the wave port impedance.nI'm interested in the input impedance of the transducer, no of the magnetostatic wave per se. I want to model a CPW instead of a thin-wire because the response of the transducer greatly changes your ability to launch spin waves efficiently (within a bandwidth it can increase your radiation resistance over that of a wire). nAnd as znaqvi said, try not to miss the unit. When dividing, or taking trigonometric function, the unit may be lost and you have to multiply the float value with *1mm or 1mnAre you saying that then in my example of $aa, it does not have units of 1/mm since I am dividing by $SubsY which has units of mm? I agree that anything in a trigonometric function will likely be lost unless you correctly cancel it out, as I do in $continuous_alpha.n