SFGRAM draws a meteogram for surface data.

INPUT PARAMETERS
 
    SFFILE    *Surface data file
    DATTIM    *Date/time
    STATION   *Stations
    TRACE1    *Parms/colors/range/witness
    TRACE2    *Parms/colors/range/witness
    TRACE3    *Parms/colors/range/witness
    TRACE4    *Parms/colors/range/witness
    TRACE5    *Parms/colors/range/witness
    NTRACE    *Number of traces
    TAXIS     *Time1-time2-tinc;lbl;gln;tck
    BORDER    *Background color/dash/width
    MARKER    *Marker color/type/size/width/hw
    TITLE     *Title color/line/title
    CLEAR     *Clear screen flag
    DEVICE    *Graphics device
    PANEL     *Panel location/color/dash/width
    TEXT      *Text size/font/width/hw flag
 
 

PROGRAM DESCRIPTION
 
    SFGRAM draws a time series plot for surface data.  Up to
    five traces may be drawn in a single plot.  NTRACE determines
    the number of traces to draw.  If NTRACE is 5, the plot area
    will be divided into fifths; if NTRACE is 4, the plot area will
    be divided into fourths, etc.  If STATION is a single station,
    all the traces will be for that station.  If STATION is a
    list of stations, TRACE1 will plot data from the first station,
    TRACE2 will plot data from the second station, etc.

    Each TRACE parameter contains specifications for the parameters
    to be plotted in the corresponding trace.  The format for
    each trace is:

	parms/colors/range/witness!parms/colors/range/witness

    The parameters before the ! will be labeled on the left of the
    plot; those after the ! will be labeled on the right.
    Any GEMPAK surface parameter may be entered.  Real valued
    parameters will be drawn as a graph.  Character valued
    parameters will be rotated 90 degrees and written on the plot.
    Symbols are plotted for the symbol parameters.  For GUST and
    GUMS, the character, G, will be plotted.

    Up to four parameters may be plotted along each axis.  The
    parameters must be separated using semicolons.  Character
    and symbols may only be plotted in positions 1, 2 or 3,
    where position 1 is at the bottom of the trace, position 2
    is in the middle and position 3 is at the top.

    Each parameter name may be followed by a colon, the size or
    line dash type, a second colon, and the width.  For example,
    WSYM:.5:5 will draw weather symbols half the default size with
    a line width of 5.  TMPF:3 will plot a temperature line using
    dash pattern 3.

    The colors for the parameters must also be separated using
    semicolons.  If a single number is entered, all parameters
    are drawn in that color.  If a zero is entered, the current
    default color is used.

    The range specifies the scaling of the y-axis.  The format
    is:
		start;stop;increment

    Note that, in this program, the parts of range must be
    separated using semicolons.  If no range is given, it
    is selected using the data values.

    Witness lines may be  specified for each TRACE.  These are
    horizontal dotted lines.  A list of y values, separated by
    semicolons, may be entered.  Alternatively, if WITNESS =
    YES, a witness line will be centered on the plot.

    The time axis is specified in TAXIS as a minimum time, a
    maximum time, and a time increment separated with dashes.
    If any or all of the parts of TAXIS is blank, reasonable
    values will be selected by the program.


EXAMPLES
 
    1.  Plot a meteogram for BWI using all the times in the file.
        Use the default time axis and background colors.  Do not
        plot markers.  TRACE1 plots TMPC and DWPC in colors 2
        and 3 with a data range from -10 to 30 degrees and a
        witness line at 0 degrees.  TRACE2 plots VSBY using a
        solid line connecting points with labels on the left and
        PMSL using a dashed line with labels on the right.  TRACE3
        plots directional arrows at the bottom of the plot along
        with the wind speed in knots and wind gusts.  TRACE4
        plots cloud cover codes at the bottom and weather symbols
        with size = .6 at the top.  TRACE5 plots ALTM.

        SFFILE   = data:sfdata.sfc
        DATTIM   = all
        STATION  = @bwi
        TRACE1   = tmpc;dwpc/2;3/-10;30;10/0
        TRACE2   = vsby!pmsl:3
        TRACE3   = darr;sknt;gust
        TRACE4   = clds;;wsym:.6
        TRACE5   = altm
        NTRACE   = 5
        TAXIS    =
        BORDER   = 1
        MARKER   = 0
        TITLE    = 1
        CLEAR    = yes
        DEVICE   = xw
        PANEL    =
        TEXT     =


ERROR MESSAGES
 
    [SFGRAM  +3]    Hardware text cannot generally be rotated.
    [SFGRAM  -1]    Fatal error initializing TAE.
    [SFGRAM  -2]    Fatal error reading TAE parameters.
    [SFGRAM  -3]    Fatal error initializing GEMPLT.
    [SFGRAM  -4]    No stations have been entered.
    [SFGRAM  -5]    ... cannot be plotted in position 4.
    [SFGRAM  -6]    The time range along the x axis is 0.
    [SFGRAM  -7]    The parameter ... cannot be computed.
    [SFGRAM  -8]    The graph coordinates are invalid.
    [SFGRAM  -9]    There  is no data at station ....
    [SFGRAM -10]    Station ... is invalid.
    [SFGRAM -11]    There are no times in the file.
    [SFGRAM -12]    The time ... is invalid.
    [SFGRAM -14]    The file ... cannot be opened.
    [SFGRAM -15]    There are no parameters specified.
    [SFGRAM -16]    Error in specifying TAXIS.