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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
       University 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
       specify 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.

       -P phaseangle
              For complex-valued datasets, this option causes the output
              values to be rotated by phaseangle degrees in the complex plane.
              That is, they are multiplied by exp(2 pi i phaseangle / 360).

       -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.

              Note that this option is generally unnecessary, since mpb-data
              can already find the relevant dataset(s) for files created by
              MPB.  Also, note that mpb-data treats the dataset specified by
              this option as a real scalar dataset and does not include the
              exp(ikx) factors when extending the dataset to multiple periods.

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

AUTHORS
       Written by Steven G. Johnson.  Copyright (c) 1999-2012 by the
       Massachusetts Institute of Technology.

SEE ALSO
       mpb(1)

MPB                            January 27, 2000                    MPB-DATA(1)