Module « matplotlib.pyplot »

Fonction quiver - module matplotlib.pyplot

Signature de la fonction quiver

def quiver(*args, data=None, **kw) 

Description

quiver.__doc__

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 auto-scales 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 swept-back 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, Y : 1D or 2D array-like, 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 case ``len(X)`` and ``len(Y)``
    must match the column and row dimensions of *U* and *V*.

U, V : 1D or 2D array-like
    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.

C : 1D or 2D array-like, 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 :math:`\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 array-like, 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
      counter-clockwise 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, counter-clockwise 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'``.

scale : float, 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 x-axis
    units. To plot vectors in the x-y plane, with u and v having
    the same units as x and y, use
    ``angles='xy', scale_units='xy', scale=1``.

width : float, 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.

headwidth : float, default: 3
    Head width as multiple of shaft width.

headlength : float, default: 5
    Head length as multiple of shaft width.

headaxislength : float, default: 4.5
    Head length at shaft intersection.

minshaft : float, 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!

minlength : float, 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'.

color : color 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 : `~matplotlib.collections.PolyCollection` properties, optional
    All other keyword arguments are passed on to `.PolyCollection`:

    Properties:
    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: ndarray 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
    contains: unknown
    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_position: unknown
    offsets: (N, 2) or (2,) array-like
    path_effects: `.AbstractPathEffect`
    picker: None or bool or float or callable
    pickradius: float
    rasterized: bool
    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.