GPLTLN draws a map, latitude/longitude lines with a selected marker,
and various image and graphic products.

INPUT PARAMETERS
 
    MAP       Map color/dash/width/filter flag
    MSCALE    fgc;bgc;mask/units/lat;hide/values/anch/x;y/ln;wd/freq|text_info|t
    GAREA     Graphics area
    PROJ      Map projection/angles/margins|drop flag
    SATFIL    Satellite image filename(s)
    RADFIL    Radar image filename(s)
    IMCBAR    Color/ornt/anch/x;y/ln;wd/freq
    LAT       Latitude
    LON       Longitude
    PANEL     Panel loc/color/dash/width/regn
    MARKER    Marker color/type/size/width/hw
    TITLE     Title color/line/title
    TEXT      Size/fnt/wdth/brdr/N-rot/just/hw flg
    CLEAR     Clear screen flag
    DEVICE    Device|name|x size;y size|color type
    LUTFIL    Enhancement lookup table filename
    STNPLT    Txtc/txt attr|marker attr|stnfil#col
    VGFILE    Vgfile | scale file | attribute file | filter
    PLUS      Plus sign size/width
 
 

PROGRAM DESCRIPTION
 
    GPLTLN draws a map and/or latitude/longitude lines in every 10
    degrees with a selected marker for a specified graphics area.
    A plus sign is placed at the latitude/longitude intersections.
    Plots may be drawn in any GEMPAK projection and may be overlaid
    on images.  GPLTLN also post-processes NMAP Vector Graphics Files
    (VGFs) to create products in any format supported by GEMPAK device
    drivers.

    Images are animated if more than one image file is specified in
    SATFIL or RADFIL.  Images are sampled to correspond to the
    geographic area specified by GAREA.  The geographic area may be
    defined graphically by setting GAREA using the CURSOR command.
    This command allows for interactive zooming of images and the
    corresponding map and latitude/longitude plots.

    GPLTLN can post-process NMAP VGFs to create products in different
    formats including AFOS, AWIPS Redbook, GIF, TIFF, 6 bit FAX, and
    PostScript.  The VGFILE variable specifies the input VGF and the
    DEVICE variable specifies the desired output format.  VGF object
    attributes may be modified when creating products by specifying
    a table (attribute file) in the VGFILE variable.  This table uses
    the same format as the $GEMTBL/pgen/setting.tbl to alter object
    attributes.  For example, the color, width, and smoothing flag
    attributes can be changed for a solid line by setting them in the
    attribute file.  The table, $GEMTBL/pgen/uattribd.tbl, provides a
    template for this capability.  Refer to this table for additional
    details.  GPLTLN can also scale attributes for an entire class of
    objects by specifying a table (scale file) in the VGFILE
    variable.  Refer to the scale.fax table in $GEMTBL/pgen for
    additional information.


EXAMPLES
 
    1.  Draw a Polar Stereographic map of the Northern Hemisphere.
	Draw the map in color 1. Draw lat/lon lines with marker 15
	in color 3. Place a plus sign on lat/lon intersections every
	10 degrees in size 1 and width 3. The color is same with
	the marker.

	MAP	 =  1
	GAREA	 =  -10;-130;-10;50
	PROJ	 =  str/90;-80;0
	SATFIL	 =
	RADFIL	 =
        IMCBAR   =
	LAT	 =
	LON	 =
	PANEL	 =  0
	MARKER   =  3/15
	TITLE	 =  1
	TEXT	 =  1
	CLEAR	 =  yes
	DEVICE	 =  xw
	LUTFIL   =
	STNPLT   =
	VGFILE	 =
	PLUS	 =  1/3


ERROR MESSAGES
 
    [GPLTLN  -1]    Fatal error initializing TAE.
    [GPLTLN  -2]    Fatal error reading TAE parameters.
    [GPLTLN  -3]    Fatal error initializing GEMPLT.
