Input and Output Files

Most WXP programs will require an data file to process.  WXP can process many different types of files and plot information based on their content.  Because of this, programs are generally isolated to a specific type of file rather than one generic program to process every file type.

File Paths

The location of data files are specified by a set of resources called path resources.  These specify directories where data files are located and where generated data files are to be put.  By default, all files go in the local directory but this is often not used since most files will be saved in a directory on a server.   WXP provides the user with the following path resources:

• file_path - Specifies location of database files.
• data_path - Specifies location of data files produced by the WXP and LDM ingestors including WMO, HDS and McIDAS data files.
• con_path - Specifies location of converted data files produced by WXP decoders including WXP and netCDF file types.
• grid_path - Specifies location of grid files produced by WXP gridding programs.
• raw_path - Specifies location of raw files produced by WXP plotting programs.
• image_path - Specifies location of image files produced by WXP graphics programs.

Ingest Programs

The ingest program whether it be the WXP ingest program or the LDM, will produce several types of files based on the content of the file.  This includes surface, upper air, radar, NIDS, GRIB and text data files.  

The ingestor has a setup file which defines which data types and products are to be saved as well as defining the file name convention that these files will have.  The setup files are either ingest.bul for the WXP ingestor or the pqact.conf file for the LDM.  For example, textual forecasts may go into a forecast file based on the date and the have a file extension describing the type of data in that file:

   F[^OT]         >>   %D/%y%m%d%6h_for.wmo  %D/%y%m%d%6h_for.hdr

This will put all the forecast products for 6 hours into a file with a for.wmo extension.  The %y%m%d%h are used to create a filename based on the current year, month, day and hour. The final keyword is %D, which is the value of the data_path resource. This is where all ingested data goes.  Finally, a header file will be created so quick searching of data can be done.

Decoder Programs

Often it is necessary to decode the ingested data files for easier use by the WXP analysis programs.  The decoders rely on a name convention file to define both the input file name and to be used in creating the output file name.  Each type of data has a tag that is used to find the naming convention.  For example, when converting surface data using the sacvt program, the input tag is sfc_dat and the output tag is sfc_cvt.  These will then be crossed referenced in the name convention file:

   sfc_dat       %D/%y%m%d%h_sao.wmo
   sfc_cvt       %C/%y%m%d%h_sao.wxp

Similar to the ingest setup file, the name convention file uses the same nomenclature for naming its files.  In this case, the input to the decoder is from the ingested data files in the data_path directory.  The output of the decoder will go into a file in the con_path directory.  These path resources can be changed on the command line. Also, the tags themselves can be changed using the in_file and out_file resource.

The out_file resource can also be used to specify the type of decoded output file such as ASCII (wxp) or netCDF (cdf).  When specifying a file type, the type is appended to the tag: sfc_cvt_wxp and  sfc_cvt_cdf which can be used to denote specific file name conventions for each file type:

   sfc_cvt_wxp     %C/%y%m%d%h_sao.wxp
   sfc_cvt_cdf     %C/%y%m%d%h_sao.nc

Analysis Programs

These programs will either access data from the decoders or from the ingested data. Similar to the decoders, these programs use the name convention file to determine input and output naming conventions.   The name convention is also used in providing a list of available files for use at the file name prompt.

   List of available files:
   /home/wxp/convert/96112205_sao.wxp
   /home/wxp/convert/96112206_sao.wxp

   Enter the surface filename: 96112206

The user may wish to select the filename directly from the list or use the current resource to specify a current or latest available file.

These analysis programs often have optional output files that can be created by specifying the out_file resource.  In this case, the out_file resource specifies the type of output file and can be used to specify the output name convention tag.

   sfc_grd      %G/%v_%m%d%h.grd
   sfc_raw      %R/%v_%m%d%h.raw

In this case, special wildcard characters are set to specify internal parameters such as plot variable, vertical level and forecast time.

The contouring (contour) and raw file plotting programs (mapplt and grid) can then use these files.  Here is a list of file name tags:

* The MOS tags are not set.  Only the strings "ngm", "ngm_ua", "eta_ua", "mrfx" need to appear in the tag for the program to recognize the type of file.
** The GRIB data is defined through a model lookup table.

Name Conventions

The standard naming conventions involve the date and time of the file plus an extension that is based on the file type. The three basic naming conventions are:

• hhmmddyy.eee (hmdy)
• yymmddhh.eee (ymdh)
• yymmddhh_eee.ttt (ymdh_t)

where yy is the last two digits of the year, mm is month of the year, dd is the day of the month and hh is the hour in Universal Time (GMT or Z). Also, the eee is the file extension describing the content of the file and with the ymdh_t naming convention, there is a ttt extension which describes the format of the data.   Typical data types and associated file extensions are as follows:

The actual naming conventions are defined in the name convention file.  This is setup by the system administrator.  

in_file and out_file Resources

These resources can be used to specify the tags and the resulting file name conventions used in the program.  Each program has default tags compiled into the program but they can be overridden on the command line:

   -if=sfc_dat -of=sfc_cvt

The resource can specify a whole file name convention string instead of a tag:

   -if=%C/%y%m%d%h_sao.wxp

or specific files

   -if=/tmp/file.cvt