MIF 2.1 Migration Guide, OOMMF 1.2a2 to 1.2a3

As part of the alpha development of the OOMMF 1.2 Oxs program, the MIF file format has been upgraded from the MIF 2.0 format used in the OOMMF 1.2a1 and 1.2a2 to MIF 2.1 in the OOMMF 1.2a3 release. The overall structure of the MIF 2.1 format is still a Tcl script with a collection of Specify blocks, but additional commands have been added, some Oxs_Ext objects have been removed, and the Specify block internal structure for others has been reworked. The most significant changes are detailed below.

The command line program mifconvert will convert many MIF 2.0 files to the MIF 2.1 equivalent. However, the MIF 2.x format is quite rich, and complicated 2.0 files may not be properly converted. In all events, the reader should refer to the MIF 2.1 and "Standard Oxs_Ext Child Classes" documentation in the OOMMF User's Guide for additional details.

1. Sections and Atlases
   • In MIF 2.1, the Oxs_RectangularSection class is gone. It's functionality has been absorbed into the atlas classes, most directly Oxs_BoxAtlas. The Oxs_SectionAtlas has been replaced by the Oxs_MultiAtlas. For example, in the the MIF 2.0 format the region specification might look like this:

     	-----------------------------------------------
     	 OLD  MIF 2.0  OLD  MIF 2.0  OLD  MIF 2.0  OLD
     	-----------------------------------------------
     	  Specify Oxs_SectionAtlas:WorldAtlas {
     	     top { Oxs_RectangularSection {
     		 xrange {0 500e-9}
     		 yrange {0 250e-9}
     		 zrange {3e-9 9e-9}
     	     }   }
     	     bottom { Oxs_RectangularSection {
     		 xrange {0 500e-9}
     		 yrange {0 250e-9}
     		 zrange {0 3e-9}
     	     }   }
     	     world { Oxs_RectangularSection {
     		 xrange {0 500e-9}
     		 yrange {0 250e-9}
     		 zrange {0 9e-9}
     	     }   }
     	  }
     	-----------------------------------------------
     	 OLD  MIF 2.0  OLD  MIF 2.0  OLD  MIF 2.0  OLD
     	-----------------------------------------------

     In the new MIF 2.1 format this would be rendered as:

     	-----------------------------------------------
     	 NEW  MIF 2.1  NEW  MIF 2.1  NEW  MIF 2.1  NEW
     	-----------------------------------------------
     	  Specify Oxs_MultiAtlas:WorldAtlas {
     	     atlas { Oxs_BoxAtlas:top {
     		 xrange {0 500e-9}
     		 yrange {0 250e-9}
     		 zrange {3e-9 9e-9}
     	     }   }
     	     atlas { Oxs_BoxAtlas:bottom {
     		 xrange {0 500e-9}
     		 yrange {0 250e-9}
     		 zrange {0 3e-9}
     	     }   }
     	  }
     	-----------------------------------------------
     	 NEW  MIF 2.1  NEW  MIF 2.1  NEW  MIF 2.1  NEW
     	-----------------------------------------------

     If only one rectangular region needs to be delineated, then a single top-level Oxs_BoxAtlas can fulfill the requirement.

   • Oxs_ScriptAtlas: In 2.1, the user specified regions are enumerated from 1, instead of 0 as in 2.0. This affects the designated script return value. Also, the default import argument list to the designated script in 2.1 is a triplet of relative coordinates, rather than a 9-tuple. However, Oxs_ScriptAtlas in 2.1 does support the script_args option, which can be used to reproduce the 2.0 import argument convention.

2. Energy terms:
   • The Oxs_Exchange6Ngbr class has dropped the sublist grouping from the value list specifying the exchange constant A. For example:

     	-----------------------------------------------
     	 OLD  MIF 2.0  OLD  MIF 2.0  OLD  MIF 2.0  OLD
     	-----------------------------------------------
     	  Specify Oxs_Exchange6Ngbr {
     	    default_A 30e-12
     	    atlas :atlas
     	    A  {
     	      { top top 13e-12 }
     	      { top bottom 20e-12 }
     	    }
     	  }
     	-----------------------------------------------
     	 OLD  MIF 2.0  OLD  MIF 2.0  OLD  MIF 2.0  OLD
     	-----------------------------------------------

     becomes

     	-----------------------------------------------
     	 NEW  MIF 2.1  NEW  MIF 2.1  NEW  MIF 2.1  NEW
     	-----------------------------------------------
     	  Specify Oxs_Exchange6Ngbr {
     	    default_A 30e-12
     	    atlas :atlas
     	    A  {
     	        top top 13e-12
     	        top bottom 20e-12
     	    }
     	  }
     	-----------------------------------------------
     	 NEW  MIF 2.1  NEW  MIF 2.1  NEW  MIF 2.1  NEW
     	-----------------------------------------------

   • The "Hscale" option in the Oxs_UZeeman class has been renamed "multiplier".

3. Driver changes:
   • The Oxs_StandardDriver class has been renamed Oxs_TimeDriver. This is to allow for the new Oxs_MinDriver class, used to control energy minimization evolvers such as Oxs_CGEvolve (a conjugate gradient based minimizer).
   • The "min_timestep" and "max_timestep" options have been moved out of the driver block and into the evolver block (Oxs_EulerEvolve).
   • The "number_of_stages" option has been renamed "stage_count", and made optional. The driver class will now automatically determine the total number of changes.
   • The "stage_count_check" flag has been introduced. The default value is 1, in which case a check is made that all objects have compatible stage count expectations. Explicitly setting this flag to 0 disables this check.
   • The basename option has been moved from the Miscellaneous block (which is now obsolete) into the driver block.

4. Field initializers:
   • The "Init" suffix has been dropped from all field object. For example, "Oxs_RandomVectorFieldInit" in 2.0 is just "Oxs_RandomVectorField" in 2.1.
   • There is a change to the list nesting in AtlasField objects:

     	-----------------------------------------------
     	 OLD  MIF 2.0  OLD  MIF 2.0  OLD  MIF 2.0  OLD
     	-----------------------------------------------
               Specify Oxs_AtlasScalarFieldInit:foo {
                 atlas :atlas
                 default_value 7
                 values {
                     { top 6.1 }
                     { bottom 4.2 }
                 }
               }
     
               Specify Oxs_AtlasVectorFieldInit:bar {
                 atlas :atlas
                 default_value { 1 0 0 }
                 values {
                     { top 0.1 0.2 0.3 }
                     { bottom 1.1 2.2 3.3 }
                 }
               }
     	-----------------------------------------------
     	 OLD  MIF 2.0  OLD  MIF 2.0  OLD  MIF 2.0  OLD
     	-----------------------------------------------

     is now

     	-----------------------------------------------
     	 NEW  MIF 2.1  NEW  MIF 2.1  NEW  MIF 2.1  NEW
     	-----------------------------------------------
               Specify Oxs_AtlasScalarField:foo {
                 atlas :atlas
                 default_value 7
                 values {
                     top 6.1
                     bottom 4.2
                 }
               }
     
               Specify Oxs_AtlasVectorField:bar {
                 atlas :atlas
                 default_value { 1 0 0 }
                 values {
                     top { 0.1 0.2 0.3 }
                     bottom { 1.1 2.2 3.3 }
                 }
               }
     	-----------------------------------------------
     	 NEW  MIF 2.1  NEW  MIF 2.1  NEW  MIF 2.1  NEW
     	-----------------------------------------------

   • Script field objects, i.e., Oxs_ScriptScalarField and Oxs_ScriptVectorField, now require a bounding box specification inside their Specify block. This may be either an atlas reference, or explicit xrange/yrange/zrange specifications. Also, the default import argument list for the designated script is a triplet of relative coordinates in 2.1 rather than the 9-tuple in 2.0. The script_args option is available to mimic the old behavior.
   • When used as imbedded objects inside the Specify blocks of other classes, the Oxs_UniformScalarField and Oxs_UniformVectorField objects can be implicitly specified. For example

     	-----------------------------------------------
     	 NEW  MIF 2.1  NEW  MIF 2.1  NEW  MIF 2.1  NEW
     	-----------------------------------------------
     	  Specify Oxs_UniaxialAnisotropy {
     	    K1  { Oxs_UniformScalarField { value 530e3 } }
     	    axis { Oxs_UniformVectorField {
     		     vector { 0 0 1 }
     	    } }
     	  }
     	-----------------------------------------------
     	 NEW  MIF 2.1  NEW  MIF 2.1  NEW  MIF 2.1  NEW
     	-----------------------------------------------

     is equivalent to

     	-----------------------------------------------
     	 NEW  MIF 2.1  NEW  MIF 2.1  NEW  MIF 2.1  NEW
     	-----------------------------------------------
     	  Specify Oxs_UniaxialAnisotropy {
     	    K1  530e3
     	    axis { 0 0 1 }
     	  }
     	-----------------------------------------------
     	 NEW  MIF 2.1  NEW  MIF 2.1  NEW  MIF 2.1  NEW
     	-----------------------------------------------

     However, if you use the implicit specification for the Oxs_UniformVectorField class, then the "norm" option is not available.

5. Miscellaneous block: This block is gone in 2.1. The random seed value is now specified with the RandomSeed Tcl extension command, usually placed near the top of the MIF file. The other Miscellaneous block option, basename, has been moved into the driver block.

6. The name of the "ignore" option inside Specify blocks has been changed to "comment". There is additionally a new Tcl extension command, Ignore, which may be used at the top-level to disable Specify blocks. This replaces the Skip proc commonly defined inside MIF 2.0 files.

MIF Changes: OOMMF 1.2a0 to 1.2a1
Back to OOMMF 1.2 software page or

The National Institute of Standards and Technology (NIST) is an agency of the U.S. Commerce Department.