GDTHGT draws contours and wind barbs or arrows on a time section at a point within a grid. INPUT PARAMETERS GPOINT *Grid point GDATTIM *Grid date/time GVCORD *Grid vertical coordinate GFUNC *Grid function GVECT *Grid vector function GDFILE *Grid file PTYPE *Plot type/h:w ratio/margins YAXIS *Ystrt/ystop/yinc/lbl;gln;tck BORDER *Background color/dash/width LINE *Line color/type/width/label CINT *Contour interval/min/max WIND *Wind symbol/siz/wdth/typ/hdsz TITLE *Title color/line/title CLEAR *Clear screen flag SCALE *Scaling factor PANEL *Panel location/color/dash/width DEVICE *Graphics device TEXT *Text size/font/width/hw flag PROGRAM DESCRIPTION GDTHGT is a user contributed program that draws a vertical time section at a location in a grid field. The location is specified by setting GPOINT. Gridded data are interpolated to the time-section plane at regular intervals of time specified in GDATTIM. The grid vertical coordinate (GVCORD) may be PRES, THTA, or HGHT, depending on what is available in the grid file. The vertical axis scaling, set in PTYPE, can be LIN, LOG, KAP or STUVE. STUVE and KAP are the same; SKEWT may not be entered. The plot aspect ratio and margins may also be entered in PTYPE. Vector fields may be specified in GVECT and displayed as arrows or barbs. The vector function CIRC cannot be computed for time sections. If M is entered in WIND, winds will be displayed in meters per second unless the KNOTV operator has been specified in GVECT, in which case the winds will be displayed in knots. IF K is entered in WIND, the wind is displayed in knots. EXAMPLES 1. Plot temperature in Celsius on a log-P chart on a time section from f00 to f24 at BWI. Plot the contours in color number 2, using thick, solid lines. Plot wind barbs for the forecast wind. Plot the chart to 50 millibars using the default labels. Accept default values for the other parameters. GPOINT = bwi GDATTIM = all GVCORD = pres GFUNC = temp GVECT = wnd WIND = bm1 GDFILE = gemdata:hrcbob.grd PTYPE = log YAXIS = /50 CINT = SCALE = LINE = 2/1/7 BORDER = TITLE = CLEAR = yes DEVICE = xw TEXT = PANEL = 2. Now, using the same file, plot a log pressure time section of the vorticity advection, scaled by 10**9. Use a height-to-width plot ratio of 2. GFUNC = adv(avor(obs);obs) GVECT = PTYPE = log/2 SCALE = 9 WIND = am1 ERROR MESSAGES [GDTHGT -1] Fatal error initializing TAE. [GDTHGT -2] Fatal error reading TAE parameters. [GDTHGT -3] Fatal error initializing GEMPLT. [GDTHGT -4] Invalid vertical coordinate. [GDTHGT -7] Invalid axis type. [GDTHGT -8] Invalid vertical coordinate type. [GDTHGT -20] Input for YAXIS is invalid.