matplotlib.quiver.Quiver¶

class
matplotlib.quiver.
Quiver
(ax, *args, scale=None, headwidth=3, headlength=5, headaxislength=4.5, minshaft=1, minlength=1, units='width', scale_units=None, angles='uv', width=None, color='k', pivot='tail', **kw)[source]¶ Bases:
matplotlib.collections.PolyCollection
Specialized PolyCollection for arrows.
The only API method is set_UVC(), which can be used to change the size, orientation, and color of the arrows; their locations are fixed when the class is instantiated. Possibly this method will be useful in animations.
Much of the work in this class is done in the draw() method so that as much information as possible is available about the plot. In subsequent draw() calls, recalculation is limited to things that might have changed, so there should be no performance penalty from putting the calculations in the draw() method.
The constructor takes one required argument, an Axes instance, followed by the args and kwargs described by the following pyplot interface documentation:
Plot a 2D field of arrows.
Call signature:
quiver([X, Y], U, V, [C], **kw)
X, Y define the arrow locations, U, V define the arrow directions, and C optionally sets the color.
Arrow size
The default settings autoscales the length of the arrows to a reasonable size. To change this behavior see the scale and scale_units parameters.
Arrow shape
The defaults give a slightly sweptback arrow; to make the head a triangle, make headaxislength the same as headlength. To make the arrow more pointed, reduce headwidth or increase headlength and headaxislength. To make the head smaller relative to the shaft, scale down all the head parameters. You will probably do best to leave minshaft alone.
Arrow outline
linewidths and edgecolors can be used to customize the arrow outlines.
Parameters:  X, Y1D or 2D arraylike, optional
The x and y coordinates of the arrow locations.
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 caselen(X)
andlen(Y)
must match the column and row dimensions of U and V. U, V1D or 2D arraylike
The x and y direction components of the arrow vectors.
They must have the same number of elements, matching the number of arrow locations. U and V may be masked. Only locations unmasked in U, V, and C will be drawn.
 C1D or 2D arraylike, optional
Numeric data that defines the arrow colors by colormapping via norm and cmap.
This does not support explicit colors. If you want to set colors directly, use color instead. The size of C must match the number of arrow locations.
 units{'width', 'height', 'dots', 'inches', 'x', 'y' 'xy'}, default: 'width'
The arrow dimensions (except for length) are measured in multiples of this unit.
The following values are supported:
 'width', 'height': The width or height of the axis.
 'dots', 'inches': Pixels or inches based on the figure dpi.
 'x', 'y', 'xy': X, Y or \(\sqrt{X^2 + Y^2}\) in data units.
The arrows scale differently depending on the units. For 'x' or 'y', the arrows get larger as one zooms in; for other units, the arrow size is independent of the zoom state. For 'width or 'height', the arrow size increases with the width and height of the axes, respectively, when the window is resized; for 'dots' or 'inches', resizing does not change the arrows.
 angles{'uv', 'xy'} or arraylike, default: 'uv'
Method for determining the angle of the arrows.
'uv': The arrow axis aspect ratio is 1 so that if U == V the orientation of the arrow on the plot is 45 degrees counterclockwise from the horizontal axis (positive to the right).
Use this if the arrows symbolize a quantity that is not based on X, Y data coordinates.
'xy': Arrows point from (x, y) to (x+u, y+v). Use this for plotting a gradient field, for example.
Alternatively, arbitrary angles may be specified explicitly as an array of values in degrees, counterclockwise from the horizontal axis.
In this case U, V is only used to determine the length of the arrows.
Note: inverting a data axis will correspondingly invert the arrows only with
angles='xy'
. scalefloat, optional
Number of data units per arrow length unit, e.g., m/s per plot width; a smaller scale parameter makes the arrow longer. Default is None.
If None, a simple autoscaling algorithm is used, based on the average vector length and the number of vectors. The arrow length unit is given by the scale_units parameter.
 scale_units{'width', 'height', 'dots', 'inches', 'x', 'y', 'xy'}, optional
If the scale kwarg is None, the arrow length unit. Default is None.
e.g. scale_units is 'inches', scale is 2.0, and
(u, v) = (1, 0)
, then the vector will be 0.5 inches long.If scale_units is 'width' or 'height', then the vector will be half the width/height of the axes.
If scale_units is 'x' then the vector will be 0.5 xaxis units. To plot vectors in the xy plane, with u and v having the same units as x and y, use
angles='xy', scale_units='xy', scale=1
. widthfloat, optional
Shaft width in arrow units; default depends on choice of units, above, and number of vectors; a typical starting value is about 0.005 times the width of the plot.
 headwidthfloat, default: 3
Head width as multiple of shaft width.
 headlengthfloat, default: 5
Head length as multiple of shaft width.
 headaxislengthfloat, default: 4.5
Head length at shaft intersection.
 minshaftfloat, default: 1
Length below which arrow scales, in units of head length. Do not set this to less than 1, or small arrows will look terrible!
 minlengthfloat, default: 1
Minimum length as a multiple of shaft width; if an arrow length is less than this, plot a dot (hexagon) of this diameter instead.
 pivot{'tail', 'mid', 'middle', 'tip'}, default: 'tail'
The part of the arrow that is anchored to the X, Y grid. The arrow rotates about this point.
'mid' is a synonym for 'middle'.
 colorcolor or color sequence, optional
Explicit color(s) for the arrows. If C has been set, color has no effect.
This is a synonym for the
PolyCollection
facecolor parameter.
Other Parameters:  **kwargs
PolyCollection
properties, optional All other keyword arguments are passed on to
PolyCollection
: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
arraylike or scalar or None animated
bool antialiased
or aa or antialiasedsbool or list of bools array
ndarray capstyle
{'butt', 'round', 'projecting'} clim
(vmin: float, vmax: float) clip_box
Bbox
clip_on
bool clip_path
Patch or (Path, Transform) or None cmap
Colormap
or str or Nonecolor
color or list of rgba tuples contains
unknown edgecolor
or ec or edgecolorscolor or list of colors or 'face' facecolor
or facecolors or fccolor or list of colors figure
Figure
gid
str hatch
{'/', '\', '', '', '+', 'x', 'o', 'O', '.', '*'} in_layout
bool joinstyle
{'miter', 'round', 'bevel'} label
object linestyle
or dashes or linestyles or lsstr or tuple or list thereof linewidth
or linewidths or lwfloat or list of floats norm
Normalize
or Noneoffset_position
unknown offsets
arraylike (N, 2) or (2,) path_effects
AbstractPathEffect
picker
None or bool or callable pickradius
unknown rasterized
bool or None sketch_params
(scale: float, length: float, randomness: float) snap
bool or None transform
Transform
url
str urls
list of str or None visible
bool zorder
float
See also
Axes.quiverkey
 Add a key to a quiver plot.

__init__
(ax, *args, scale=None, headwidth=3, headlength=5, headaxislength=4.5, minshaft=1, minlength=1, units='width', scale_units=None, angles='uv', width=None, color='k', pivot='tail', **kw)[source]¶ The constructor takes one required argument, an Axes instance, followed by the args and kwargs described by the following pyplot interface documentation:
Plot a 2D field of arrows.
Call signature:
quiver([X, Y], U, V, [C], **kw)
X, Y define the arrow locations, U, V define the arrow directions, and C optionally sets the color.
Arrow size
The default settings autoscales the length of the arrows to a reasonable size. To change this behavior see the scale and scale_units parameters.
Arrow shape
The defaults give a slightly sweptback arrow; to make the head a triangle, make headaxislength the same as headlength. To make the arrow more pointed, reduce headwidth or increase headlength and headaxislength. To make the head smaller relative to the shaft, scale down all the head parameters. You will probably do best to leave minshaft alone.
Arrow outline
linewidths and edgecolors can be used to customize the arrow outlines.
Parameters:  X, Y1D or 2D arraylike, optional
The x and y coordinates of the arrow locations.
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 caselen(X)
andlen(Y)
must match the column and row dimensions of U and V. U, V1D or 2D arraylike
The x and y direction components of the arrow vectors.
They must have the same number of elements, matching the number of arrow locations. U and V may be masked. Only locations unmasked in U, V, and C will be drawn.
 C1D or 2D arraylike, optional
Numeric data that defines the arrow colors by colormapping via norm and cmap.
This does not support explicit colors. If you want to set colors directly, use color instead. The size of C must match the number of arrow locations.
 units{'width', 'height', 'dots', 'inches', 'x', 'y' 'xy'}, default: 'width'
The arrow dimensions (except for length) are measured in multiples of this unit.
The following values are supported:
 'width', 'height': The width or height of the axis.
 'dots', 'inches': Pixels or inches based on the figure dpi.
 'x', 'y', 'xy': X, Y or \(\sqrt{X^2 + Y^2}\) in data units.
The arrows scale differently depending on the units. For 'x' or 'y', the arrows get larger as one zooms in; for other units, the arrow size is independent of the zoom state. For 'width or 'height', the arrow size increases with the width and height of the axes, respectively, when the window is resized; for 'dots' or 'inches', resizing does not change the arrows.
 angles{'uv', 'xy'} or arraylike, default: 'uv'
Method for determining the angle of the arrows.
'uv': The arrow axis aspect ratio is 1 so that if U == V the orientation of the arrow on the plot is 45 degrees counterclockwise from the horizontal axis (positive to the right).
Use this if the arrows symbolize a quantity that is not based on X, Y data coordinates.
'xy': Arrows point from (x, y) to (x+u, y+v). Use this for plotting a gradient field, for example.
Alternatively, arbitrary angles may be specified explicitly as an array of values in degrees, counterclockwise from the horizontal axis.
In this case U, V is only used to determine the length of the arrows.
Note: inverting a data axis will correspondingly invert the arrows only with
angles='xy'
. scalefloat, optional
Number of data units per arrow length unit, e.g., m/s per plot width; a smaller scale parameter makes the arrow longer. Default is None.
If None, a simple autoscaling algorithm is used, based on the average vector length and the number of vectors. The arrow length unit is given by the scale_units parameter.
 scale_units{'width', 'height', 'dots', 'inches', 'x', 'y', 'xy'}, optional
If the scale kwarg is None, the arrow length unit. Default is None.
e.g. scale_units is 'inches', scale is 2.0, and
(u, v) = (1, 0)
, then the vector will be 0.5 inches long.If scale_units is 'width' or 'height', then the vector will be half the width/height of the axes.
If scale_units is 'x' then the vector will be 0.5 xaxis units. To plot vectors in the xy plane, with u and v having the same units as x and y, use
angles='xy', scale_units='xy', scale=1
. widthfloat, optional
Shaft width in arrow units; default depends on choice of units, above, and number of vectors; a typical starting value is about 0.005 times the width of the plot.
 headwidthfloat, default: 3
Head width as multiple of shaft width.
 headlengthfloat, default: 5
Head length as multiple of shaft width.
 headaxislengthfloat, default: 4.5
Head length at shaft intersection.
 minshaftfloat, default: 1
Length below which arrow scales, in units of head length. Do not set this to less than 1, or small arrows will look terrible!
 minlengthfloat, default: 1
Minimum length as a multiple of shaft width; if an arrow length is less than this, plot a dot (hexagon) of this diameter instead.
 pivot{'tail', 'mid', 'middle', 'tip'}, default: 'tail'
The part of the arrow that is anchored to the X, Y grid. The arrow rotates about this point.
'mid' is a synonym for 'middle'.
 colorcolor or color sequence, optional
Explicit color(s) for the arrows. If C has been set, color has no effect.
This is a synonym for the
PolyCollection
facecolor parameter.
Other Parameters:  **kwargs
PolyCollection
properties, optional All other keyword arguments are passed on to
PolyCollection
: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
arraylike or scalar or None animated
bool antialiased
or aa or antialiasedsbool or list of bools array
ndarray capstyle
{'butt', 'round', 'projecting'} clim
(vmin: float, vmax: float) clip_box
Bbox
clip_on
bool clip_path
Patch or (Path, Transform) or None cmap
Colormap
or str or Nonecolor
color or list of rgba tuples contains
unknown edgecolor
or ec or edgecolorscolor or list of colors or 'face' facecolor
or facecolors or fccolor or list of colors figure
Figure
gid
str hatch
{'/', '\', '', '', '+', 'x', 'o', 'O', '.', '*'} in_layout
bool joinstyle
{'miter', 'round', 'bevel'} label
object linestyle
or dashes or linestyles or lsstr or tuple or list thereof linewidth
or linewidths or lwfloat or list of floats norm
Normalize
or Noneoffset_position
unknown offsets
arraylike (N, 2) or (2,) path_effects
AbstractPathEffect
picker
None or bool or callable pickradius
unknown rasterized
bool or None sketch_params
(scale: float, length: float, randomness: float) snap
bool or None transform
Transform
url
str urls
list of str or None visible
bool zorder
float
See also
Axes.quiverkey
 Add a key to a quiver plot.

__module__
= 'matplotlib.quiver'¶

draw
(renderer)[source]¶ Draw the Artist (and its children) using the given renderer.
This has no effect if the artist is not visible (
Artist.get_visible
returns False).Parameters:  renderer
RendererBase
subclass.
Notes
This method is overridden in the Artist subclasses.
 renderer

quiver_doc
= "\nPlot a 2D field of arrows.\n\nCall signature::\n\n quiver([X, Y], U, V, [C], **kw)\n\n*X*, *Y* define the arrow locations, *U*, *V* define the arrow directions, and\n*C* optionally sets the color.\n\n**Arrow size**\n\nThe default settings autoscales the length of the arrows to a reasonable size.\nTo change this behavior see the *scale* and *scale_units* parameters.\n\n**Arrow shape**\n\nThe defaults give a slightly sweptback arrow; to make the head a\ntriangle, make *headaxislength* the same as *headlength*. To make the\narrow more pointed, reduce *headwidth* or increase *headlength* and\n*headaxislength*. To make the head smaller relative to the shaft,\nscale down all the head parameters. You will probably do best to leave\nminshaft alone.\n\n**Arrow outline**\n\n*linewidths* and *edgecolors* can be used to customize the arrow\noutlines.\n\nParameters\n\nX, Y : 1D or 2D arraylike, optional\n The x and y coordinates of the arrow locations.\n\n If not given, they will be generated as a uniform integer meshgrid based\n on the dimensions of *U* and *V*.\n\n If *X* and *Y* are 1D but *U*, *V* are 2D, *X*, *Y* are expanded to 2D\n using ``X, Y = np.meshgrid(X, Y)``. In this case ``len(X)`` and ``len(Y)``\n must match the column and row dimensions of *U* and *V*.\n\nU, V : 1D or 2D arraylike\n The x and y direction components of the arrow vectors.\n\n They must have the same number of elements, matching the number of arrow\n locations. *U* and *V* may be masked. Only locations unmasked in\n *U*, *V*, and *C* will be drawn.\n\nC : 1D or 2D arraylike, optional\n Numeric data that defines the arrow colors by colormapping via *norm* and\n *cmap*.\n\n This does not support explicit colors. If you want to set colors directly,\n use *color* instead. The size of *C* must match the number of arrow\n locations.\n\nunits : {'width', 'height', 'dots', 'inches', 'x', 'y' 'xy'}, default: 'width'\n The arrow dimensions (except for *length*) are measured in multiples of\n this unit.\n\n The following values are supported:\n\n  'width', 'height': The width or height of the axis.\n  'dots', 'inches': Pixels or inches based on the figure dpi.\n  'x', 'y', 'xy': *X*, *Y* or :math:`\\sqrt{X^2 + Y^2}` in data units.\n\n The arrows scale differently depending on the units. For\n 'x' or 'y', the arrows get larger as one zooms in; for other\n units, the arrow size is independent of the zoom state. For\n 'width or 'height', the arrow size increases with the width and\n height of the axes, respectively, when the window is resized;\n for 'dots' or 'inches', resizing does not change the arrows.\n\nangles : {'uv', 'xy'} or arraylike, default: 'uv'\n Method for determining the angle of the arrows.\n\n  'uv': The arrow axis aspect ratio is 1 so that\n if *U* == *V* the orientation of the arrow on the plot is 45 degrees\n counterclockwise from the horizontal axis (positive to the right).\n\n Use this if the arrows symbolize a quantity that is not based on\n *X*, *Y* data coordinates.\n\n  'xy': Arrows point from (x, y) to (x+u, y+v).\n Use this for plotting a gradient field, for example.\n\n  Alternatively, arbitrary angles may be specified explicitly as an array\n of values in degrees, counterclockwise from the horizontal axis.\n\n In this case *U*, *V* is only used to determine the length of the\n arrows.\n\n Note: inverting a data axis will correspondingly invert the\n arrows only with ``angles='xy'``.\n\nscale : float, optional\n Number of data units per arrow length unit, e.g., m/s per plot width; a\n smaller scale parameter makes the arrow longer. Default is *None*.\n\n If *None*, a simple autoscaling algorithm is used, based on the average\n vector length and the number of vectors. The arrow length unit is given by\n the *scale_units* parameter.\n\nscale_units : {'width', 'height', 'dots', 'inches', 'x', 'y', 'xy'}, optional\n If the *scale* kwarg is *None*, the arrow length unit. Default is *None*.\n\n e.g. *scale_units* is 'inches', *scale* is 2.0, and ``(u, v) = (1, 0)``,\n then the vector will be 0.5 inches long.\n\n If *scale_units* is 'width' or 'height', then the vector will be half the\n width/height of the axes.\n\n If *scale_units* is 'x' then the vector will be 0.5 xaxis\n units. To plot vectors in the xy plane, with u and v having\n the same units as x and y, use\n ``angles='xy', scale_units='xy', scale=1``.\n\nwidth : float, optional\n Shaft width in arrow units; default depends on choice of units,\n above, and number of vectors; a typical starting value is about\n 0.005 times the width of the plot.\n\nheadwidth : float, default: 3\n Head width as multiple of shaft width.\n\nheadlength : float, default: 5\n Head length as multiple of shaft width.\n\nheadaxislength : float, default: 4.5\n Head length at shaft intersection.\n\nminshaft : float, default: 1\n Length below which arrow scales, in units of head length. Do not\n set this to less than 1, or small arrows will look terrible!\n\nminlength : float, default: 1\n Minimum length as a multiple of shaft width; if an arrow length\n is less than this, plot a dot (hexagon) of this diameter instead.\n\npivot : {'tail', 'mid', 'middle', 'tip'}, default: 'tail'\n The part of the arrow that is anchored to the *X*, *Y* grid. The arrow\n rotates about this point.\n\n 'mid' is a synonym for 'middle'.\n\ncolor : color or color sequence, optional\n Explicit color(s) for the arrows. If *C* has been set, *color* has no\n effect.\n\n This is a synonym for the `~.PolyCollection` *facecolor* parameter.\n\nOther Parameters\n\n**kwargs : `~matplotlib.collections.PolyCollection` properties, optional\n All other keyword arguments are passed on to `.PolyCollection`:\n\n \n .. table::\n :class: propertytable\n\n ================================================================================================= =====================================================================================================\n Property Description \n ================================================================================================= =====================================================================================================\n :meth:`agg_filter <matplotlib.artist.Artist.set_agg_filter>` a filter function, which takes a (m, n, 3) float array and a dpi value, and returns a (m, n, 3) array\n :meth:`alpha <matplotlib.collections.Collection.set_alpha>` arraylike or scalar or None \n :meth:`animated <matplotlib.artist.Artist.set_animated>` bool \n :meth:`antialiased <matplotlib.collections.Collection.set_antialiased>` or aa or antialiaseds bool or list of bools \n :meth:`array <matplotlib.cm.ScalarMappable.set_array>` ndarray \n :meth:`capstyle <matplotlib.collections.Collection.set_capstyle>` {'butt', 'round', 'projecting'} \n :meth:`clim <matplotlib.cm.ScalarMappable.set_clim>` (vmin: float, vmax: float) \n :meth:`clip_box <matplotlib.artist.Artist.set_clip_box>` `.Bbox` \n :meth:`clip_on <matplotlib.artist.Artist.set_clip_on>` bool \n :meth:`clip_path <matplotlib.artist.Artist.set_clip_path>` Patch or (Path, Transform) or None \n :meth:`cmap <matplotlib.cm.ScalarMappable.set_cmap>` `.Colormap` or str or None \n :meth:`color <matplotlib.collections.Collection.set_color>` color or list of rgba tuples \n :meth:`contains <matplotlib.artist.Artist.set_contains>` unknown \n :meth:`edgecolor <matplotlib.collections.Collection.set_edgecolor>` or ec or edgecolors color or list of colors or 'face' \n :meth:`facecolor <matplotlib.collections.Collection.set_facecolor>` or facecolors or fc color or list of colors \n :meth:`figure <matplotlib.artist.Artist.set_figure>` `.Figure` \n :meth:`gid <matplotlib.artist.Artist.set_gid>` str \n :meth:`hatch <matplotlib.collections.Collection.set_hatch>` {'/', '\\\\', '', '', '+', 'x', 'o', 'O', '.', '*'} \n :meth:`in_layout <matplotlib.artist.Artist.set_in_layout>` bool \n :meth:`joinstyle <matplotlib.collections.Collection.set_joinstyle>` {'miter', 'round', 'bevel'} \n :meth:`label <matplotlib.artist.Artist.set_label>` object \n :meth:`linestyle <matplotlib.collections.Collection.set_linestyle>` or dashes or linestyles or ls str or tuple or list thereof \n :meth:`linewidth <matplotlib.collections.Collection.set_linewidth>` or linewidths or lw float or list of floats \n :meth:`norm <matplotlib.cm.ScalarMappable.set_norm>` `.Normalize` or None \n :meth:`offset_position <matplotlib.collections.Collection.set_offset_position>` unknown \n :meth:`offsets <matplotlib.collections.Collection.set_offsets>` arraylike (N, 2) or (2,) \n :meth:`path_effects <matplotlib.artist.Artist.set_path_effects>` `.AbstractPathEffect` \n :meth:`picker <matplotlib.artist.Artist.set_picker>` None or bool or callable \n :meth:`pickradius <matplotlib.collections.Collection.set_pickradius>` unknown \n :meth:`rasterized <matplotlib.artist.Artist.set_rasterized>` bool or None \n :meth:`sketch_params <matplotlib.artist.Artist.set_sketch_params>` (scale: float, length: float, randomness: float) \n :meth:`snap <matplotlib.artist.Artist.set_snap>` bool or None \n :meth:`transform <matplotlib.artist.Artist.set_transform>` `.Transform` \n :meth:`url <matplotlib.artist.Artist.set_url>` str \n :meth:`urls <matplotlib.collections.Collection.set_urls>` list of str or None \n :meth:`visible <matplotlib.artist.Artist.set_visible>` bool \n :meth:`zorder <matplotlib.artist.Artist.set_zorder>` float \n ================================================================================================= =====================================================================================================\n\n\nSee Also\n\n.Axes.quiverkey : Add a key to a quiver plot.\n"¶

remove
()[source]¶ Remove the artist from the figure if possible.
The effect will not be visible until the figure is redrawn, e.g., with
FigureCanvasBase.draw_idle
. Callrelim
to update the axes limits if desired.Note:
relim
will not see collections even if the collection was added to the axes with autolim = True.Note: there is no support for removing the artist's legend entry.