MIF 1.2

The MIF 1.2 format is a minor modification to the MIF 1.1 format, which supports limited 3D problem specification. It can be read by the Oxs 3D solvers, and, with certain restrictions, by the mmSolve 2D solvers as well. The mmProbEd problem editor can read and write this format. The mifconvert command line tool can be used to convert between the MIF 1.1 and MIF 1.2 formats, and to convert from the MIF 1.x formats to the Oxs MIF 2.1 format. mifconvert is also called automatically by Oxs solvers when a MIF 1.x file is input to them, so questions about the details of Oxs interpretation of MIF 1.x files can be answered by running mifconvert separately on the input MIF 1.x file.

There are four differences between the MIF 1.1 and 1.2 formats. In the MIF 1.2 format:

1. The first line reads: # MIF 1.2
2. The CellSize record takes three parameters: $x$-dimension, $y$-dimension, and $z$-dimension (in meters).
3. The 3dSlab, 2dSlab, 3dCharge, and FastPipe parameters of the DemagType record are deprecated.
4. The new record SolverType is introduced. Valid values are Euler, RK2, RK4, RKF54, and CG, requesting a first order Euler, second order Runge-Kutta, fourth order Runge-Kutta, fifth(+fourth) order Runge-Kutta-Fehlberg, and Conjugate-Gradient solvers, respectively. This record is optional, with default value of RKF54.

If the CellSize record has only one parameter, then it is interpreted in the same manner as in the MIF 1.1 format, i.e., the parameter is taken as the $x$- and $y$-dimension of the computation cell, and the $z$-dimension is set to the part thickness.

The mmSolve 2D solvers will accept files in the MIF 1.2 format provided the CellSize record meets the restrictions of those solvers, namely, the $x$- and $y$-dimensions must be the same, and the $z$-dimension must equal the part thickness. The SolverType record, if any, is ignored.

The Oxs 3D solvers will read files in the MIF 1.2 format, but support only the ConstMag and None demagnetization kernels. All other DemagType records are silently converted to ConstMag. The SolverType record is converted into the appropriate solver+driver pair.

OOMMF Documentation Team
September 27, 2024