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Miscellaneous Analysis

Map and Raw File Plotting

The map plotting program called mapplt can be used for five purposes:

  • Base Maps -- drawing simple base maps by specifying domain information via the region or plot_domain resource. This is also handy for adding maps to overlay plot when the plot is complete rather than when the programs want to display the map.
  • Text Labels -- annotating plots by allowing text labels to be placed above and below the plotting area. This is done by specifying labels on the command line. The location and alignment of the labels are specified a location prefix VH: followed by the text string. This will place text either above 'u' or below 'l' the plot, either left 'l', right 'r' or centered 'c'. Multiple labels may be specified. This is handy if the user wants control over what the final labels are to be for an overlay plot. The wxpfile program can be used to generate certain labels.
  • Raw File Plotting -- displaying data from raw data files. If the user has created a raw data file, use this program to display the results. If the raw file contains multiple columns, all columns can be plotted or a specific one can be selected based on column number of header string. Also, a specific station identifier can be specified to only plot that station's data from the raw file. Also, the raw file may contain annotation and attributes information that can modify a station's output. A sample hurricane chart plotted from a raw file can be seen below.
  • City Database Plotting -- displaying station locations from a city database file. This can be handy in locating various reporting stations and for determining which stations have a certain plotting priority. The color of the output can be changed based on its station priority.
  • Plotting Locations -- plotting specific stations or specific locations using the identifier resource. This can be used to plot the location of a specific set of stations either by searching for its location in the city databases or by specifying a latitude and longitude. Also, the same annotation/attribute information as is specified in the raw data files to plot weather symbols or wind barbs.
mapplt -pd=ll,23.10,-63.60,25,17,2.76,2.76 track.raw-ID:ll:co=black \
   track.raw-LINE:mk=plus:co=black track.raw-LINE:wi=3 -de-d
track.gif (12788 bytes)

Raw Data Gridding and Contouring

A program is provided to grid and contour data from raw data files called grid. Raw data files can be generated by non-WXP programs or by any of the plotting programs such as sfcwx, upairwx and fouswx. This allows data to be manipulated prior to the gridding process such as with the rawmath program. The grid program will take raw data, fit it to a grid and then contour it as all other gridding and contouring programs do. The resulting grid can be saved to a file for future use.

Contour Existing Grids

The contour program is provided to contour existing grids. This includes grids generated by sfccalc, upcalc, focalc, grid and grbcalc as well as the model GRIB files.  This program also uses a file name extension to extract a specific grid from a multiple grid file.

Wind Vector Display from Existing Grids

The vector program is provided to display vector plots given two existing grids (U and V components). This program will work just as well with non-wind data such as gradients of a particular variable as it will with wind components but is generally used for displaying wind vectors. The program will prompt the user for two grid files and then will draw the vectors.


For further information about WXP, email technical-support@weather.unisys.com
Last updated by Dan Vietor on June 6, 1998