windbarbs

windbarbs(u, v; kwargs...)

Plot wind barb field from two component grids with the x and y components of the wind field.

or
julia windbarbs(arg1; kwargs...)
Plot wind barb field from a data table with the x and y components of the wind field.
Description

Read two 2-D grid files which represents the x- and y-components of a wind field and produces a wind field plot by drawing wind barbs with orientation and barbs according to the information in the files. Alternatively, polar coordinate r, theta grids may be given instead. Alternatively, a data table with the x and y components of the wind field may be given.

Required Arguments

  • compx Contains the x-components of the wind field.

  • compy Contains the y-components of the wind field.

Optional Arguments

  • A or polar : – polar=true
    The grid files contain polar (r, theta) components instead of Cartesian (x, y) [Default is Cartesian components]. This option is valid only when the input files are 2-D grids.

  • G or fill : – fill=fill
    Sets color or shade for wind barb interiors (see ) [Default is no fill].

  • I or inc or increment or spacing : – inc=x_inc | inc=(x_inc, y_inc) | inc=“x”“multx”[“/multy”]
    Only plot wind barbs at nodes every x_inc, y_inc apart (must be multiples of original grid spacing). Append m for arc minutes or s for arc seconds. Alternatively, use inc=“x” to specify the multiples multx[/multy] directly [Default plots every node]. Example inc=“x10/5” to select every other 10 nodes in x and 5 nodes in y. NOTE: by default we estimate good values so that the arrows do no overlap so you may start by jumping this option unless some fine control is desired.

  • N or noclip or no_clip : noclip=true
    Do NOT clip wind barbs at map boundaries [Default will clip].

  • Q or barbs : – barbs=(length=length, angle=angle, fill=fill, pen=pen, justify=“b|e|c”, speed=speed, width=width)
    Modify wind barb parameters. Append wind barb length [Default is 0.5c]. Several modifiers may be appended to specify the placement of barbs, their shapes, and the justification of the wind barb. Below, left and right refers to the side of the wind barb line when viewed from the start point to the end point of the segment. Chose among these modifiers:

    • angle - Set the angle of the wind barb [120].
    • fill - Turn off fill (if -) or set the wind barb fill [Default fill is used, which may be no fill].
    • pen - Sets the wind barb pen attributes. If pen has a leading - then the outline is not drawn [Default pen is used, and outline is drawn].
    • justify - Determines how the input x, y point relates to the wind barb. Choose from beginning [default], end, or center.
    • speed - Set the wind speed which corresponds to a long barb [default 5].
    • width - Set the width of wind barbs.
  • T or sign_scale : – sign_scale=true
    Means the azimuths of Cartesian data sets should be adjusted according to the signs of the scales in the x- and y-directions [Leave alone]. This option can be used to convert vector azimuths in cases when a negative scale is used in one of both directions (e.g., positive down).
  • Z or azimuth : – azimuth=true
    The theta grid provided contains azimuths rather than directions (implies polar=true). This option is valid only when the input files are 2-D grids.

Examples

To draw the wind field given by the files r.nc and theta.nc on a barb plot with 0.25 cm length and centered on the node locations, run:

windbarb("r.nc", "theta.nc", polar=true, barbs=(len=0.25, justify=:c), show=true)

To plot a geographic data sets given the files comp_x.nc and comp_y.nc, and only plot every 3rd node in either direction, try:

windbarb("comp_x.nc", "comp_y.nc", inc="x3", proj=:guess, barbs=(len=0.25, justify=:c), show=true)

See Also

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