wmbarb

The procedure wmbarb uses the wind barb functions from the Wmap package to draw wind barbs. Note: This function is only available in version 4.1.1 of NCL. If your site is licensed for version 4.1, then you can get version 4.1.1 for free. To get version 4.1.1 of NCAR Graphics software, please contact your site representative. If you don't know who your site representative is, then send email to ncarginf@ucar.edu or call (303) 497-1201.

Synopsis

    procedure wmbarb(
        wid[1]    : graphic,
        x[*]      : float,
        y[*]      : float,
        u[*]      : float,
        v[*]      : float,
    )

Arguments

wid

An NCL workstation identifier specifying where you want to draw your wind barbs. The identifier wid is the value returned from an NCL call that created a workstation.

x

A 1-dimensional array specifying X-coordinate values.

y

A 1-dimensional array specifying Y-coordinate values.

u

A 1-dimensional array specifying X-components of wind vectors at the associated (x,y) coordinates specified in arguments two and three of this procedure.

u

A 1-dimensional array specifying Y-components of wind vectors at the associated (x,y) coordinates specified in arguments two and three of this procedure.

Description

The procedure wmbarb draws wind barbs at the (x,y) coordinates specified in arguments two and three of the procedure. The (x,y) coordinates specify the center position of the base of the barb and u and v specify the components of the wind vector. The angle at which the wind barb is drawn is determined by the vector (u,v) and the magnitude of that vector determines the wind speed in knots.

Certain parameters may be set to control the appearance of a wind barb, such as its size, color, and so forth. The procedure wmsetp is used to set parameter values, and the function wmgetp is used to retrieve parameter values. The parameters applicable to wmbarb are: COL, WBF, WBA, WBC, WBD, WBR, WBS, WBT.

The procedure wmbarb does not call frame.

begin
;
;  Create an X11 workstation.
;
 
      wid = create "wmbarb_example" xWorkstationClass defaultapp
        "wkPause" : True
      end create
;
;  Draw wind barbs.
;
      x = (/0.25, 0.75, 0.75, 0.25/)
      y = (/0.25, 0.25, 0.75, 0.75/)
      u = (/50., -50., -50.,  50./)
      v = (/50.,  50., -50., -50./)
      wmsetp("wbs",0.2)
      wmbarb(wid, x, y, u, v)
      frame(wid)
;
;  Get parameter value.
;
      size = wmgetp("wbs")
      print(size)
end