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contour - Contours existing grids


contour [parameters...] filename


Command Line Resource Default Description
-h help No Lists basic help information.
-df=filename default .wxpdef Sets the name of the resource file.
-na=name name contour Specifies the name used in resource file parsing.
-ba batch No Run program in batch mode
-me=level message out2 Specifies level of messages to be displayed
  • file information - mess
-fp=filepath file_path current directory Specifies location of database files.  
-dp=datapath data_path current directory Specifies the location (path) of the input raw data files. This may be modified in the name convention file.
-cp=conpath con_path current directory Specifies the location (path) of the input surface converted data files. This may be modified in the name convention file.
-rp=rawpath raw_path current directory Specifies the location of the output raw files generated by the program. These files will not be generated unless the out_file resource is specified and the output is plotted data.
-gp=gridpath grid_path current directory Specifies the location of the output grid files generated by the program. These files are not generated unless the out_file resource is specified and the output is a gridded field.
-ip=imagepath image_path current directory Specifies the default location of the output GIF images generated by the program.
-nc=name_conv name_conv name_conv The name convention file specifies how files are named in WXP. This sets which name convention file to use.
-if=in_file in_file grd Specifies the input file name tag. The default is grd, but it can be modified to any value in the filename convention file. A full name convention can be specified as well.
-mf=mapfile[,...] map_file wxp.map or
cont.dat, country.dat for domains outside North America
Specifies the name of the map database file. Multiple maps can be specified along with attributes to describe how to draw the map.
-cu=[hour|la] current None This specifies to use current data files. The current filename is based on the name convention. An optional hour can be specified for older data. If la is specified, the program will search back to find the most recent available file.
-ho=hour hour None This resource specifies the exact hour that a data file is valid for. This locks in the start hour for a multi-file sequence.
-nh=num_hour num_hour 0 (no loop) This specifies the number of hours that will be used in the plot. If this is not specified, a single hourly plot will appear. If this is specified, a loop of plots over this time will be generated.
-pd=domain plot_domain User prompt
Batch: first domain in wxp.reg file.
This specifies the plotting domain. The projection, aspect ratio and the domain size are specified.
-re=region region Same as plot domain This resource is synonymous with the plot_domain.
-pl=plot_type plot_type User prompt
Batch: fill contours or vectors
Specifies the type of output plot. By default, the user is prompted for the plot type. To produce a contour or vector plot, use the following plot types:


  • cf -- color fill contours
  • ln -- line contours
  • dln -- dashed line contours
  • ndln -- negative dash line contours
  • lcf -- both line and color fill contours
  • gvalue -- plot gridpoint values
  • none -- for no output plot
-sc=scale_factor plot_scale 1.0 Specifies a scaling factor for all plotted text, symbols, vectors, etc.
-fm=format plot_format None Specifies the output format of the plots.  This is generally used to specify how many decimal places get displayed on the plot and in the output raw files.
-pp=param[,param...] plot_param None Specifies additional plotting parameters. See the plot_param resource for more details.
-dr=drawable[,...] draw all Specifies which part of the plot is to be drawn.
-la=label[,...] label Program defaults Specifies the labels to be plotted around the plot. By default, labels are generated by the program and plotted above and below the plot. This resource overrides these labels.
-in=interval con_interval None for plots, User prompt for grids. Batch: 0 Specifies the contour interval to use in contouring grids. This can also be used to color code plotted data and vectors.
-cb=base con_base Lowest contour value, maximum wind speed Specifies the base value for color fill contours, and wind speed per grid distance. For more details, see the con_base resource.
-fl=font_list font_list modern.fnt Specifies a list of fonts to use in the plots.
-ct=color_table color_table wxp.clr Specifies the color table to use in the plot. This maps color names to actual RGB color values.
-cot=color[:attr] color_text white
for inverse plots.
Specifies the text color for labels above and below the plot.
-cod=color[:attr] color_data green Specifies the color for plotted data.
-com=color[:attr] color_map red Specifies the color for background maps.
-coln=color[:attr] color_line magenta:st=dsh Specifies the color for lat/lon lines.
-cocm=color[:attr] color_cmap black Specifies the color for color fill contour maps.
-coco=color[:attr] color_cont white
for inverse plots.
Specifies the color for line contours.
-cof=[val:]color[:attr],... color_fill A predefined color set based on the wxp.clr color table Specifies the color fill contour color set. See the color_fill resource for more details.
-cola=color[:attr] color_label white
for inverse plots.
Specifies the line contour label color.
-cocl=color[:attr] color_clabel black Specifies the color fill contour label color.
-de=device[,...] device User prompt
Batch: display
Specifies the output device.
-ti=title title Program name Specifies the window title.
-ic icon Off Specifies whether to open window in iconified mode.
-bg=color background black
white for inverse plots
Specifies the background color of the window.
-ge=geometry geometry 640x480 Specifies the window and paper geometry.
filename[+time:level:var[:units]] filename None
User Pompt
Batch: current=la
The name of the surface converted data file to be plotted. An optional sequence number can be added to designate the time for non-WXP files.


This program contours existing grid files either created by WXP or preformatted GRIB files. WXP grid files can be created with the out_file resource being set on the contouring programs such as sfccalc and upcalc.  For multigrid files, additional information can be tacked onto the filename to denote which grid to use. If not specified ont he command line, the filename will be prompted for.  The filename syntax is:


where filename is the name of the grid file to use.  If a relative path is used, the value of the grid_path is prepended to the filename.  The filename can be "std" where standard input is used.  

The extra information following the "+" or "#" defines which grid to use within a multigrid file. The value of num represents the sequence number of the grid in the file.  Grids are numbered starting at 0 (zero).  This number can be determined through a griblook listing.  

The values of time, level, and var make it possible to specify the grid based on typical grid information.  Possible values for each are:

  • time: init,06,12,18,24,30,36,42,48,60,72,d3,d4,d5,d6,d7,d8,d9,d10
  • level: sfc, sl (sea level), trop, mwnd, 1000, 850, 700, 500, 400, 300, 200, 100
  • var: temp, rhum, pres, vvel, uwnd, vwnd, prec, lift

The unit specification allows the user to change the units of the grid before performing the math.  

The user may also specify the input file using the in_file resource to specify a name convention tag and the current resource. To generate a loop, the num_hour resource can be specified. This will tell the program to loop through this number of hours.

The domain defaults to the domain of the first grid unless changed through the plot_domain resource. The domain can be interactively changed using the mouse once the plot has been generated.

The program will now open the graphics window and start processing the data. The user will be prompted for the output device. Then the grid file is opened and data read in. The background map will plot first unless the output is a color fill contour in which the map plots last. Next, the maximum and minimum of the grid are displayed for the user to pick an appropriate contour interval. Then, the contour or vector plot will display.

There are several plot types.  For contour plots, there is:

  • ln - line contours
  • dln - dashed line contours
  • ndln - negative dashed line contours. All contours less than 0 are dashed. The breakoff can be reset with the con_base resource.
  • cf - color fill contours.  These are contours where the areas between the contour lines are filled with a progressive color scheme. By default, this is a 15 color scale in which the colors wrap around if there are more than 15 color level.  The color scheme can be set by the color_fill resource.

For vectors:

  • vect -- vectors/arrows
  • strm -- streamlines
  • barb -- wind barbs

When the plot is complete, output can be saved to a GIF image file, spooled to the printer or the plot can be zoomed.  When zooming the image, the plot will redraw to the new domain.  It will also add more stations to the plot depending on the size of the domain. When the user is finished with the plot, the enter key can be hit which closes the window and returns the user to the variable prompt.


   contour -pl=cf -in=2 -de=d temp.grd

This produces a color fill contour plot of temperature at an interval of 2.



  • sfccalc - the surface contouring program
  • upcalc - the upper air contouring program

For further information about WXP, email technical-support@weather.unisys.com
Last updated by Dan Vietor on June 10, 1998