WMDRFT - plots weather map front lines.

       To  use WMDRFT or c_wmdrft, load the NCAR Graphics libraries ncarg, ncarg_gks, and ncarg_c, preferably in
       that order.

       #include <ncarg/gks.h>

       void c_wmdrft(int n, float *x, float *y)

       Copyright (C) 1987-2009
       University Corporation for Atmospheric Research
       The use of this Software is governed by a License Agreement.

UNIX                                              January 1995                                    WMDRFT(3NCARG)

       N           (Integer, Input) - The number of points supplied in the second and third arguments.

       X           (Real,  Input) - The X coordinates  (specified in world coordinates) of N points that specify
                   the control points of a spline curve that will be fitted to represent the  requested  weather
                   front.

       Y           (Real,  Input) - The Y coordinates  (specified in world coordinates) of N points that specify
                   the control points of a spline curve that will be fitted to represent the  requested  weather
                   front.

       WMDRFT - plots weather map front lines.

       Online: wmap, wmdflt, wmgetc, wmgeti, wmgetr, wmsetc, wmseti, wmsetr, wmap_params

       Hardcopy: WMAP - A Package for Producing Daily Weather Maps and Plotting Station Model Data

       CALL WMDRFT (N, X, Y)

       Set  the  values  for  the  appropriate  internal parameters before calling WMDRFT to produce the desired
       weather front.  The internal parameters that control the appearance of weather fronts are: ALO, ARC, BEG,
       BET, CFC, CS1, CS2, COL, DWD, END, FRO, LIN, NBZ, NMS, PAI, REV, SL1, SL2, SLF, STY, SWI, T1C, T2C,  WFC,
       and  WTY.   The  possible  fronts  are: warm, warm aloft, cold, cold aloft, stationary, stationary aloft,
       occluded, convergence line, instability line, intertropical.  As mentioned above, the points specified in
       the X and Y arrays serve as control points for a spline curve that is fitted between the first  and  last
       point.  The spline passes through the given points.  If the desired front line is reasonably smooth, then
       only a few input points need be specified.