MIF 2.2 New Extension Commands

In addition to the commands available in MIF 2.1 files, MIF 2.2 introduces the following new commands: GetMifFilename, GetMifParameters, GetOptions, SetOptions, EvalScalarField, EvalVectorField, GetAtlasRegions, and GetAtlasRegionByPosition.

GetMifFilename

The GetMifFilename command returns the full (absolute) name of the MIF file being read. This command takes no parameters.

GetMifParameters

This command takes no parameters, and returns an even numbered list of ``Parameter'' label + value pairs as set on the command line or in the Load Problem dialog box. If no parameters were specified, then the return will be an empty list.

GetOptions

The GetOptions command takes no parameters. It returns the accumulated contents of all preceding SetOptions blocks, as an even numbered list of label + value pairs.

SetOptions

In MIF 2.1 files, the output basename and output file formats are specified inside the driver's Specify block. In MIF 2.2 these specifications are moved to a separate SetOptions block. This block can be placed anywhere in the MIF file, but is typically placed near the start of the file so that it affects all output initializations. The SetOptions command takes a single argument, which is a list of label + value pairs. The default labels are:

• basename
• scalar_output_format
• scalar_field_output_format
• scalar_field_output_meshtype
• vector_field_output_format
• vector_field_output_meshtype

The basename value is used as a prefix for output filename construction by the data output routines. If basename is not specified, then the default value is taken from the filename of the input MIF file. The scalar_output_format value is a C-style printf string specifying the output format for DataTable output. This is optional, with default value ``%.17g''. The values associated with scalar_field_output_format and vector_field_output_format should be two element lists that specify the style and precision for scalar and vector field output sent to mmDisp and mmArchive. The first element in the list should be one of binary or text, specifying the output style. If binary output is selected, then the second element specifying precision should be either 4 or 8, denoting component binary output length in bytes. For text output, the second element should be a C-style printf string like that used by scalar_output_format. The default value for both scalar_field_output_format and vector_field_output_format is ``binary 8''. For scalar_field_output_meshtype and vector_field_output_meshtype the values should be either ``rectangular'' (default) or ``irregular'', specifying the grid type for the corresponding field output files.

Multiple SetOptions blocks are allowed. Label values specified in one SetOption block may be overwritten by a later SetOption block. Output formats for a given output are set during the processing of the Specify block for the enclosing Oxs_Ext object. Therefore, one can specify different formats for outputs in different Oxs_Ext objects by strategic placement of SetOptions blocks.

Additional label names may be added in the future, and may be Oxs_Ext class dependent. At present there is no checking for unknown label names, but that policy is subject to change.

An example SetOptions block:

SetOptions {
 basename fubar
 scalar_output_format %.12g
 scalar_field_output_format {text %.4g}
 scalar_field_output_meshtype irregular
 vector_field_output_format {binary 4}
}

EvalScalarField

This command allows access in a MIF file to values from a scalar field defined in a preceding Specify block. For example,

   Oxs_AtlasScalarField:Ms {
      atlas :atlas
      default_value 0
      values {
         Adisks 520e3
         Bdisks 520e3
      }
   }}

   set Ms_a [EvalScalarField :Ms 50e-9 20e-9 2e-9]

The four arguments to EvalScalarField are a reference to the scalar field (here :Ms), and the three coordinates of the point where you want the field evaluated. The coordinates are in the problem coordinate space, i.e., in meters.

EvalVectorField

This command is the same as the EvalScalarField command, except that the field reference is to a vector field, and the return value is a three item list representing the three components of the vector field at the specified point.

GetAtlasRegions

This command takes one argument, which is a reference to an atlas, and returns an ordered list of all the regions in that atlas. The first item on the returned list will always be ``universe'', which includes all points not in any of the other regions, including in particular any points outside the nominal bounds of the atlas. Sample usage:

   set regions_list [GetAtlasRegions :atlas]

GetAtlasRegionByPosition

This command takes four arguments: a reference to atlas, followed by the x, y, and z coordinates of a point using problem coordinates (i.e., meters). The return value is the name of the region containing the specified point. This name will match exactly one of the names on the list returned by the GetAtlasRegions command for the given atlas. Note that the return value might be the ``universe'' region. Sample usage:

   set rogue_region [GetAtlasRegionByPosition :atlas 350e-9 120e-9 7.5e-9]

OOMMF Documentation Team
September 30, 2022