matplotlib.axes.Axes.hexbin#

Axes.hexbin(x, y, C=None, gridsize=100, bins=None, xscale='linear', yscale='linear', extent=None, cmap=None, norm=None, vmin=None, vmax=None, alpha=None, linewidths=None, edgecolors='face', reduce_C_function=<function mean>, mincnt=None, marginals=False, *, data=None, **kwargs)[source]#

Make a 2D hexagonal binning plot of points x, y.

If C is None, the value of the hexagon is determined by the number of points in the hexagon. Otherwise, C specifies values at the coordinate (x[i], y[i]). For each hexagon, these values are reduced using reduce_C_function.

Parameters:
x, yarray-like

The data positions. x and y must be of the same length.

Carray-like, optional

If given, these values are accumulated in the bins. Otherwise, every point has a value of 1. Must be of the same length as x and y.

gridsizeint or (int, int), default: 100

If a single int, the number of hexagons in the x-direction. The number of hexagons in the y-direction is chosen such that the hexagons are approximately regular.

Alternatively, if a tuple (nx, ny), the number of hexagons in the x-direction and the y-direction. In the y-direction, counting is done along vertically aligned hexagons, not along the zig-zag chains of hexagons; see the following illustration.

(Source code, 2x.png, png)

To get approximately regular hexagons, choose \(n_x = \sqrt{3}\,n_y\).

bins'log' or int or sequence, default: None

Discretization of the hexagon values.

  • If None, no binning is applied; the color of each hexagon directly corresponds to its count value.

  • If 'log', use a logarithmic scale for the colormap. Internally, \(log_{10}(i+1)\) is used to determine the hexagon color. This is equivalent to norm=LogNorm().

  • If an integer, divide the counts in the specified number of bins, and color the hexagons accordingly.

  • If a sequence of values, the values of the lower bound of the bins to be used.

xscale{'linear', 'log'}, default: 'linear'

Use a linear or log10 scale on the horizontal axis.

yscale{'linear', 'log'}, default: 'linear'

Use a linear or log10 scale on the vertical axis.

mincntint >= 0, default: None

If not None, only display cells with at least mincnt number of points in the cell.

marginalsbool, default: False

If marginals is True, plot the marginal density as colormapped rectangles along the bottom of the x-axis and left of the y-axis.

extent4-tuple of float, default: None

The limits of the bins (xmin, xmax, ymin, ymax). The default assigns the limits based on gridsize, x, y, xscale and yscale.

If xscale or yscale is set to 'log', the limits are expected to be the exponent for a power of 10. E.g. for x-limits of 1 and 50 in 'linear' scale and y-limits of 10 and 1000 in 'log' scale, enter (1, 50, 1, 3).

Returns:
PolyCollection

A PolyCollection defining the hexagonal bins.

If marginals is True, horizontal bar and vertical bar (both PolyCollections) will be attached to the return collection as attributes hbar and vbar.

Other Parameters:
cmapstr or Colormap, default: rcParams["image.cmap"] (default: 'viridis')

The Colormap instance or registered colormap name used to map scalar data to colors.

normstr or Normalize, optional

The normalization method used to scale scalar data to the [0, 1] range before mapping to colors using cmap. By default, a linear scaling is used, mapping the lowest value to 0 and the highest to 1.

If given, this can be one of the following:

vmin, vmaxfloat, optional

When using scalar data and no explicit norm, vmin and vmax define the data range that the colormap covers. By default, the colormap covers the complete value range of the supplied data. It is an error to use vmin/vmax when a norm instance is given (but using a str norm name together with vmin/vmax is acceptable).

alphafloat between 0 and 1, optional

The alpha blending value, between 0 (transparent) and 1 (opaque).

linewidthsfloat, default: None

If None, defaults to rcParams["patch.linewidth"] (default: 1.0).

edgecolors{'face', 'none', None} or color, default: 'face'

The color of the hexagon edges. Possible values are:

  • 'face': Draw the edges in the same color as the fill color.

  • 'none': No edges are drawn. This can sometimes lead to unsightly unpainted pixels between the hexagons.

  • None: Draw outlines in the default color.

  • An explicit color.

reduce_C_functioncallable, default: numpy.mean

The function to aggregate C within the bins. It is ignored if C is not given. This must have the signature:

def reduce_C_function(C: array) -> float

Commonly used functions are:

By default will only reduce cells with at least 1 point because some reduction functions (such as numpy.amax) will error/warn with empty input. Changing mincnt will adjust the cutoff, and if set to 0 will pass empty input to the reduction function.

dataindexable object, optional

If given, the following parameters also accept a string s, which is interpreted as data[s] (unless this raises an exception):

x, y, C

**kwargsPolyCollection properties

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 and two offsets from the bottom left corner of the image

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

BboxBase or None

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

mouseover

bool

norm

Normalize or str or None

offset_transform or transOffset

Transform

offsets

(N, 2) or (2,) array-like

path_effects

list of AbstractPathEffect

paths

list of array-like

picker

None or bool or float or callable

pickradius

float

rasterized

bool

sizes

numpy.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

See also

hist2d

2D histogram rectangular bins

Examples using matplotlib.axes.Axes.hexbin#

Hexagonal binned plot

Hexagonal binned plot

hexbin(x, y, C)

hexbin(x, y, C)