matplotlib.axes.Axes.spy

Axes.spy(Z, precision=0, marker=None, markersize=None, aspect='equal', origin='upper', **kwargs)[source]

Plot the sparsity pattern of a 2D array.

This visualizes the non-zero values of the array.

Two plotting styles are available: image and marker. Both are available for full arrays, but only the marker style works for scipy.sparse.spmatrix instances.

Image style

If marker and markersize are None, imshow is used. Any extra remaining keyword arguments are passed to this method.

Marker style

If Z is a scipy.sparse.spmatrix or marker or markersize are None, a Line2D object will be returned with the value of marker determining the marker type, and any remaining keyword arguments passed to plot.

Parameters

Z(M, N) array-like

The array to be plotted.

precisionfloat or 'present', default: 0

If precision is 0, any non-zero value will be plotted. Otherwise, values of \(|Z| > precision\) will be plotted.

For scipy.sparse.spmatrix instances, you can also pass 'present'. In this case any value present in the array will be plotted, even if it is identically zero.

aspect{'equal', 'auto', None} or float, default: 'equal'

The aspect ratio of the Axes. This parameter is particularly relevant for images since it determines whether data pixels are square.

This parameter is a shortcut for explicitly calling Axes.set_aspect. See there for further details.

• 'equal': Ensures an aspect ratio of 1. Pixels will be square.
• 'auto': The Axes is kept fixed and the aspect is adjusted so that the data fit in the Axes. In general, this will result in non-square pixels.
• None: Use rcParams["image.aspect"] (default: 'equal').

origin{'upper', 'lower'}, default: rcParams["image.origin"] (default: 'upper')

Place the [0, 0] index of the array in the upper left or lower left corner of the Axes. The convention 'upper' is typically used for matrices and images.

Returns

AxesImage or Line2D

The return type depends on the plotting style (see above).

Other Parameters

**kwargs

The supported additional parameters depend on the plotting style.

For the image style, you can pass the following additional parameters of imshow:

• cmap
• alpha
• url
• any Artist properties (passed on to the AxesImage)

For the marker style, you can pass any Line2D property except for linestyle:

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	scalar or None
animated	bool
antialiased or aa	bool
clip_box	Bbox
clip_on	bool
clip_path	Patch or (Path, Transform) or None
color or c	color
dash_capstyle	CapStyle or {'butt', 'projecting', 'round'}
dash_joinstyle	JoinStyle or {'miter', 'round', 'bevel'}
dashes	sequence of floats (on/off ink in points) or (None, None)
data	(2, N) array or two 1D arrays
drawstyle or ds	{'default', 'steps', 'steps-pre', 'steps-mid', 'steps-post'}, default: 'default'
figure	Figure
fillstyle	{'full', 'left', 'right', 'bottom', 'top', 'none'}
gid	str
in_layout	bool
label	object
linestyle or ls	{'-', '--', '-.', ':', '', (offset, on-off-seq), ...}
linewidth or lw	float
marker	marker style string, Path or MarkerStyle
markeredgecolor or mec	color
markeredgewidth or mew	float
markerfacecolor or mfc	color
markerfacecoloralt or mfcalt	color
markersize or ms	float
markevery	None or int or (int, int) or slice or list[int] or float or (float, float) or list[bool]
path_effects	AbstractPathEffect
picker	float or callable[[Artist, Event], tuple[bool, dict]]
pickradius	float
rasterized	bool
sketch_params	(scale: float, length: float, randomness: float)
snap	bool or None
solid_capstyle	CapStyle or {'butt', 'projecting', 'round'}
solid_joinstyle	JoinStyle or {'miter', 'round', 'bevel'}
transform	unknown
url	str
visible	bool
xdata	1D array
ydata	1D array
zorder	float

Examples using matplotlib.axes.Axes.spy