matplotlib.pyplot.spy

matplotlib.pyplot.spy(Z, precision=0, marker=None, markersize=None, aspect='equal', origin='upper', **kwargs)

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 kwargs 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 kwargs passed to plot.

Parameters:

Z : array-like (M, N)

The array to be plotted.

precision : float or 'present', optional, 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.

origin : {'upper', 'lower'}, optional

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. If not given, rcParams["image.origin"] is used, defaulting to 'upper'.

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

Controls the aspect ratio of the axes. The aspect is of particular relevance for images since it may distort the image, i.e. pixel will not be 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').

Default: 'equal'

Returns:

ret : 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	float
animated	bool
antialiased	bool
clip_box	Bbox
clip_on	bool
clip_path	[(Path, Transform) | Patch | None]
color	color
contains	callable
dash_capstyle	{'butt', 'round', 'projecting'}
dash_joinstyle	{'miter', 'round', 'bevel'}
dashes	sequence of floats (on/off ink in points) or (None, None)
drawstyle	{'default', 'steps', 'steps-pre', 'steps-mid', 'steps-post'}
figure	Figure
fillstyle	{'full', 'left', 'right', 'bottom', 'top', 'none'}
gid	str
in_layout	bool
label	object
linestyle	{'-', '--', '-.', ':', '', (offset, on-off-seq), ...}
linewidth	float
marker	unknown
markeredgecolor	color
markeredgewidth	float
markerfacecolor	color
markerfacecoloralt	color
markersize	float
markevery	unknown
path_effects	AbstractPathEffect
picker	float or callable[[Artist, Event], Tuple[bool, dict]]
pickradius	float
rasterized	bool or None
sketch_params	(scale: float, length: float, randomness: float)
snap	bool or None
solid_capstyle	{'butt', 'round', 'projecting'}
solid_joinstyle	{'miter', 'round', 'bevel'}
transform	matplotlib.transforms.Transform
url	str
visible	bool
xdata	1D array
ydata	1D array
zorder	float

Examples using matplotlib.pyplot.spy

Spy Demos