MPB-DATA(1)						    MIT Photonic-Bands Package						       MPB-DATA(1)

NAME

       mpb-data - transformations of HDF5 files output by MPB

SYNOPSIS

       mpb-data [OPTION]... [HDF5FILE]...

DESCRIPTION

       mpb-data is a utility to perform additional processing and transformations of HDF5 files output by MPB, the MIT Photonic-Bands program.	In
       particular, it is designed to make the output more amenable to visualization by reformatting it into a rectangular grid,  extending  it	to
       multiple periods, and rescaling the data.

       MIT  Photonic  Bands  (MPB)  is	a free program to compute the band structures (dispersion relations) and electromagnetic modes of periodic
       dielectric structures.

       HDF5 is a free, portable binary format and supporting library developed by the National Center for Supercomputing Applications at the  Uni-
       versity of Illinois in Urbana-Champaign.  A single h5 file can contain multiple data sets; by default, mpb-data operates on all of the MPB-
       produced datasets in the file, but this can be changed via the -d option, or by using the syntax HDF5FILE:DATASET.

       mpb-data writes its output datasets as additional datasets in the input file(s), with "-new" appended to the dataset names.  Alternatively,
       it can write its output to a separate file, specified by the -o option.

       Note also that, by default, the output datasets are identical to the input datasets; you must use one or more of the options below to spec-
       ify a transformation (e.g. the -r/-e and -n options are very useful).

OPTIONS

       -h     Display help on the command-line options and usage.

       -V     Print the version number and copyright info for mpb-data.

       -v     Verbose output.

       -o file
	      Write output datasets to file (for the first input file only) rather than as additional datasets in the input file(s) (the default).

       -r     Output a rectangular cell with the same volume as the cell of the input data.  This option is particularly  useful  for  visualizing
	      data from non-orthogonal unit cells (e.g. a triangular lattice), as otherwise the data will appear skewed or warped in most graphics
	      programs.  This option should almost always be accompanied by the -n option to ensure a uniform resolution.

       -e x,y,z
	      As the -r option, but also make the first axis of the output along the x,y,z direction (in Cartesian coordinates) instead  of  along
	      the first lattice vector as for -r.

       -n n   Output  n grid points per lattice unit ("a").  This is useful not only for interpolating to finer (or coarser) resolutions, but also
	      to ensure that the resolution is uniform in each direction (to prevent the data from looking distorted when you visualize it).

       -x mx, -y my, -z mz
	      This tells mpb-data to output multiple periods in the corresponding lattice directions.  to use a particular  slice  of  a  two-	or
	      three-dimensional  dataset.  e.g.  -x 3.2 causes the output of 3.2 periods in the first lattice direction.  The default is to output
	      only a single period.

       -m s   Output s periods in each lattice direction; equivalent to: -x s -y s -z s.

       -T     The output has the first two dimensions (x and y) transposed.  This is useful in conjunction with the parallel (MPI) version of MPB,
	      which for performance reasons outputs all arrays with the first two dimensions transposed.  -T can undo this transposition.

       -p     Pixellized output.  Normally, the input data is linearly interpolated to the output grid, but the -p option causes it to instead use
	      the nearest grid point in the input data.  This is useful, for example, if you want to study the discretization of  the  dielectric-
	      function representation.

       -d name
	      Use  dataset  name  from	the  input  files;  otherwise,	the  first  dataset from each file is used.  Alternatively, use the syntax
	      HDF5FILE:DATASET, which allows you to specify a different dataset for each file.	You can use the h5ls command (included with  hdf5)
	      to find the names of datasets within a file.

BUGS

       Send bug reports to S. G. Johnson, stevenj@alum.mit.edu.

AUTHORS

       Written by Steven G. Johnson.  Copyright (c) 1999, 2000, 2001, 2002 by the Massachusetts Institute of Technology.

SEE ALSO

       mpb(1)

MPB
								 January 27, 2000						       MPB-DATA(1)