Generating NXT format

The gdf2nxt tool is used as follows:

Usage: gdf2nxt [options] [-t tiers] [-o observations] [input_path]
Options:
        -h, --help              Print this message
        -m, --makestylesheets   Generate one stylesheet per stream
        -v, --verbose           Print extra messages
        -t n, --tiers=n         List of tiers to generate
        -o n, --observations=n  List of observations to generate
        -p n, --outpath=n       Directory path for output  [default=./codings/]
        -c n, --conditionfile=n Name of condition CSV file [default=conditions.csv]
        -g n, --tangramprefix=n Prefix of tangram filename [default=tangram]

        [tiers]         if none, generate all known tiers
                        else, generate one tier per comma-separated argument
                                (per agent if required)
                        some tiers will also generate others
                                (objlooks requires screen-objects)
                                (phases requires docks, trials and breaks)

        [input_path]    Path containing the GDF files, conditions file, tangram
                        files, and any other input files.  Default is current directory.

        tangramprefix   Will look for files of the form tangramprefixNN.xml
                        e.g. if tangramprefix="tangram", will expect files named
                        tangram01.xml, tangram02.xml, etc.

An example usage is:

./gdf2nxt.py -v -p codings -c ~/jast/gdf2nxt-debug/jcte3_conditions.csv -g jcte3_tangram

In this example, we specify that the output should be placed in a subdirectory of the current directory called codings (in fact, the usage message shows that this is the default location for output in any case, so we did not need to specify this explicitly), and that the conditions file is located at the location ~/jast/gdf2nxt-debug/jcte3_conditions.csv. Note that we may specify a relative or absolute path for either of these options. We also specify that the tangram definition files have names of the form jcte3_tangramXX.xml, where XX is replaced by two digits representing the specific tangrams.