matplotlib.pyplot.pcolor¶

matplotlib.pyplot.
pcolor
(\*args, alpha=None, norm=None, cmap=None, vmin=None, vmax=None, data=None, \*\*kwargs)[source]¶ Create a pseudocolor plot with a nonregular rectangular grid.
Call signature:
pcolor([X, Y,] C, **kwargs)
X and Y can be used to specify the corners of the quadrilaterals.
Hint
pcolor()
can be very slow for large arrays. In most cases you should use the similar but much fasterpcolormesh
instead. See there for a discussion of the differences.Parameters:  Carraylike
A scalar 2D array. The values will be colormapped.
 X, Yarraylike, optional
The coordinates of the quadrilateral corners. The quadrilateral for
C[i, j]
has corners at:(X[i+1, j], Y[i+1, j]) (X[i+1, j+1], Y[i+1, j+1]) ++  C[i, j]  ++ (X[i, j], Y[i, j]) (X[i, j+1], Y[i, j+1])
Note that the column index corresponds to the xcoordinate, and the row index corresponds to y. For details, see the Notes section below.
The dimensions of X and Y should be one greater than those of C. Alternatively, X, Y and C may have equal dimensions, in which case the last row and column of C will be ignored.
If X and/or Y are 1D arrays or column vectors they will be expanded as needed into the appropriate 2D arrays, making a rectangular grid.
 cmapstr or
Colormap
, optional A Colormap instance or registered colormap name. The colormap maps the C values to colors. Defaults to
rcParams["image.cmap"]
(default: 'viridis'). norm
Normalize
, optional The Normalize instance scales the data values to the canonical colormap range [0, 1] for mapping to colors. By default, the data range is mapped to the colorbar range using linear scaling.
 vmin, vmaxscalar, optional, default: None
The colorbar range. If None, suitable min/max values are automatically chosen by the
Normalize
instance (defaults to the respective min/max values of C in case of the default linear scaling). edgecolors{'none', None, 'face', color, color sequence}, optional
The color of the edges. Defaults to 'none'. Possible values:
 'none' or '': No edge.
 None:
rcParams["patch.edgecolor"]
(default: 'black') will be used. Note that currentlyrcParams["patch.force_edgecolor"]
(default: False) has to be True for this to work.  'face': Use the adjacent face color.
 A color or sequence of colors will set the edge color.
The singular form edgecolor works as an alias.
 alphascalar, optional, default: None
The alpha blending value of the face color, between 0 (transparent) and 1 (opaque). Note: The edgecolor is currently not affected by this.
 snapbool, optional, default: False
Whether to snap the mesh to pixel boundaries.
Returns:  collection
matplotlib.collections.Collection
Other Parameters:  antialiasedsbool, optional, default: False
The default antialiaseds is False if the default edgecolors="none" is used. This eliminates artificial lines at patch boundaries, and works regardless of the value of alpha. If edgecolors is not "none", then the default antialiaseds is taken from
rcParams["patch.antialiased"]
(default: True). Stroking the edges may be preferred if alpha is 1, but will cause artifacts otherwise. **kwargs
Additionally, the following arguments are allowed. They are passed along to the
PolyCollection
constructor: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 or None animated
bool antialiased
or aa or antialiasedsbool or sequence 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 registered colormap name color
color or sequence of rgba tuples contains
callable edgecolor
or ec or edgecolorscolor or sequence of colors or 'face' facecolor
or facecolors or fccolor or sequence 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 ls{'', '', '.', ':', '', (offset, onoffseq), ...} linewidth
or linewidths or lwfloat or sequence of floats norm
Normalize
offset_position
{'screen', 'data'} offsets
arraylike (N, 2) or (2,) path_effects
AbstractPathEffect
picker
None or bool or float 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[str] or None visible
bool zorder
float
See also
pcolormesh
 for an explanation of the differences between pcolor and pcolormesh.
imshow
 If X and Y are each equidistant,
imshow
can be a faster alternative.
Notes
Masked arrays
X, Y and C may be masked arrays. If either
C[i, j]
, or one of the vertices surroundingC[i, j]
(X or Y at[i, j], [i+1, j], [i, j+1], [i+1, j+1]
) is masked, nothing is plotted.Grid orientation
The grid orientation follows the standard matrix convention: An array C with shape (nrows, ncolumns) is plotted with the column number as X and the row number as Y.
Handling of pcolor() endcases
pcolor()
displays all columns of C if X and Y are not specified, or if X and Y have one more column than C. If X and Y have the same number of columns as C then the last column of C is dropped. Similarly for the rows.Note: This behavior is different from MATLAB's
pcolor()
, which always discards the last row and column of C.Note
In addition to the above described arguments, this function can take a data keyword argument. If such a data argument is given, the following arguments are replaced by data[<arg>]:
 All positional and all keyword arguments.
Objects passed as data must support item access (
data[<arg>]
) and membership test (<arg> in data
).