matplotlib.axes.Axes.barbs   Axes.barbs(*args, data=None, **kwargs)[source]
 
Plot a 2D field of barbs. Call signature: barbs([X, Y], U, V, [C], **kw)
 Where X, Y define the barb locations, U, V define the barb directions, and C optionally sets the color. All arguments may be 1D or 2D. U, V, C may be masked arrays, but masked X, Y are not supported at present. Barbs are traditionally used in meteorology as a way to plot the speed and direction of wind observations, but can technically be used to plot any two dimensional vector quantity. As opposed to arrows, which give vector magnitude by the length of the arrow, the barbs give more quantitative information about the vector magnitude by putting slanted lines or a triangle for various increments in magnitude, as show schematically below: :                   /\    \
:                  /  \    \
:                 /    \    \    \
:                /      \    \    \
:               ------------------------------
 The largest increment is given by a triangle (or "flag"). After those come full lines (barbs). The smallest increment is a half line. There is only, of course, ever at most 1 half line. If the magnitude is small and only needs a single half-line and no full lines or triangles, the half-line is offset from the end of the barb so that it can be easily distinguished from barbs with a single full line. The magnitude for the barb shown above would nominally be 65, using the standard increments of 50, 10, and 5. See also https://en.wikipedia.org/wiki/Wind_barb.  Parameters 
 
X, Y1D or 2D array-like, optional


The x and y coordinates of the barb locations. See pivot for how the barbs are drawn to the x, y positions. If not given, they will be generated as a uniform integer meshgrid based on the dimensions of U and V. If X and Y are 1D but U, V are 2D, X, Y are expanded to 2D using X, Y = np.meshgrid(X, Y). In this case len(X) and len(Y) must match the column and row dimensions of U and V.  
U, V1D or 2D array-like


The x and y components of the barb shaft.  
C1D or 2D array-like, optional


Numeric data that defines the barb colors by colormapping via norm and cmap. This does not support explicit colors. If you want to set colors directly, use barbcolor instead.  
lengthfloat, default: 7


Length of the barb in points; the other parts of the barb are scaled against this.  
pivot{'tip', 'middle'} or float, default: 'tip'


The part of the arrow that is anchored to the X, Y grid. The barb rotates about this point. This can also be a number, which shifts the start of the barb that many points away from grid point.  
barbcolorcolor or color sequence


The color of all parts of the barb except for the flags. This parameter is analogous to the edgecolor parameter for polygons, which can be used instead. However this parameter will override facecolor.  
flagcolorcolor or color sequence


The color of any flags on the barb. This parameter is analogous to the facecolor parameter for polygons, which can be used instead. However, this parameter will override facecolor. If this is not set (and C has not either) then flagcolor will be set to match barbcolor so that the barb has a uniform color. If C has been set, flagcolor has no effect.  
sizesdict, optional


A dictionary of coefficients specifying the ratio of a given feature to the length of the barb. Only those values one wishes to override need to be included. These features include:  'spacing' - space between features (flags, full/half barbs) 'height' - height (distance from shaft to top) of a flag or full barb 'width' - width of a flag, twice the width of a full barb 'emptybarb' - radius of the circle used for low magnitudes   
fill_emptybool, default: False


Whether the empty barbs (circles) that are drawn should be filled with the flag color. If they are not filled, the center is transparent.  
roundingbool, default: True


Whether the vector magnitude should be rounded when allocating barb components. If True, the magnitude is rounded to the nearest multiple of the half-barb increment. If False, the magnitude is simply truncated to the next lowest multiple.  
barb_incrementsdict, optional


A dictionary of increments specifying values to associate with different parts of the barb. Only those values one wishes to override need to be included.  'half' - half barbs (Default is 5) 'full' - full barbs (Default is 10) 'flag' - flags (default is 50)   
flip_barbbool or array-like of bool, default: False


Whether the lines and flags should point opposite to normal. Normal behavior is for the barbs and lines to point right (comes from wind barbs having these features point towards low pressure in the Northern Hemisphere). A single value is applied to all barbs. Individual barbs can be flipped by passing a bool array of the same size as U and V.    Returns 
 
barbsBarbs

  Other Parameters 
 
dataindexable object, optional


If given, all parameters also accept a string s, which is interpreted as data[s] (unless this raises an exception).  **kwargs

The barbs can further be customized using PolyCollection keyword arguments:   
Property Description   
agg_filter a filter function, which takes a (m, n, 3) float array and a dpi value, and returns a (m, n, 3) array  
alpha array-like or scalar or None  
animated bool  
antialiased or aa or antialiaseds bool or list of bools  
array array-like or None  
capstyle CapStyle or {'butt', 'projecting', 'round'}  
clim (vmin: float, vmax: float)  
clip_box Bbox  
clip_on bool  
clip_path Patch or (Path, Transform) or None  
cmap Colormap or str or None  
color color or list of rgba tuples  
edgecolor or ec or edgecolors color or list of colors or 'face'  
facecolor or facecolors or fc color or list of colors  
figure Figure  
gid str  
hatch {'/', '\', '|', '-', '+', 'x', 'o', 'O', '.', '*'}  
in_layout bool  
joinstyle JoinStyle or {'miter', 'round', 'bevel'}  
label object  
linestyle or dashes or linestyles or ls str or tuple or list thereof  
linewidth or linewidths or lw float or list of floats  
norm Normalize or None  
offset_transform Transform  
offsets (N, 2) or (2,) array-like  
path_effects AbstractPathEffect  
paths list of array-like  
picker None or bool or float or callable  
pickradius float  
rasterized bool  
sizes ndarray or None  
sketch_params (scale: float, length: float, randomness: float)  
snap bool or None  
transform Transform  
url str  
urls list of str or None  
verts list of array-like  
verts_and_codes unknown  
visible bool  
zorder float       
  Examples using matplotlib.axes.Axes.barbs
 
   Wind Barbs   

   barbs(X, Y, U, V)