float, default: None
            The alpha blending value, between 0 (transparent) and 1 (opaque).

        shading : {'flat', 'nearest', 'gouraud', 'auto'}, optional
            The fill style for the quadrilateral; defaults to
            :rc:`pcolor.shading`. Possible values:

            - 'flat': A solid color is used for each quad. The color of the
              quad (i, j), (i+1, j), (i, j+1), (i+1, j+1) is given by
              ``C[i, j]``. The dimensions of *X* and *Y* should be
              one greater than those of *C*; if they are the same as *C*,
              then a deprecation warning is raised, and the last row
              and column of *C* are dropped.
            - 'nearest': Each grid point will have a color centered on it,
              extending halfway between the adjacent grid centers.  The
              dimensions of *X* and *Y* must be the same as *C*.
            - 'gouraud': Each quad will be Gouraud shaded: The color of the
              corners (i', j') are given by ``C[i', j']``. The color values of
              the area in between is interpolated from the corner values.
              The dimensions of *X* and *Y* must be the same as *C*. When
              Gouraud shading is used, *edgecolors* is ignored.
            - 'auto': Choose 'flat' if dimensions of *X* and *Y* are one
              larger than *C*.  Choose 'nearest' if dimensions are the same.

            See :doc:`/gallery/images_contours_and_fields/pcolormesh_grids`
            for more description.

        snap : bool, default: False
            Whether to snap the mesh to pixel boundaries.

        rasterized : bool, optional
            Rasterize the pcolormesh when drawing vector graphics.  This can
            speed up rendering and produce smaller files for large data sets.
            See also :doc:`/gallery/misc/rasterization_demo`.

        Returns
        -------
        `matplotlib.collections.QuadMesh`

        Other Parameters
        ----------------
        data : indexable object, optional
            DATA_PARAMETER_PLACEHOLDER

        **kwargs
            Additionally, the following arguments are allowed. They are passed
            along to the `~matplotlib.collections.QuadMesh` constructor:

        %(QuadMesh:kwdoc)s

        See Also
        --------
        pcolor : An alternative implementation with slightly different
            features. For a detailed discussion on the differences see
            :ref:`Differences between pcolor() and pcolormesh()
            <differences-pcolor-pcolormesh>`.
        imshow : If *X* and *Y* are each equidistant, `~.Axes.imshow` can be a
            faster alternative.

        Notes
        -----
        **Masked arrays**

        *C* may be a masked array. If ``C[i, j]`` is masked, the corresponding
        quadrilateral will be transparent. Masking of *X* and *Y* is not
        supported. Use `~.Axes.pcolor` if you need this functionality.

        .. _axes-pcolormesh-grid-orientation:

        **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*.

        .. _differences-pcolor-pcolormesh:

        **Differences between pcolor() and pcolormesh()**

        Both methods are used to create a pseudocolor plot of a 2D array
        using quadrilaterals.

        The main difference lies in the created object and internal data
        handling:
        While `~.Axes.pcolor` returns a `.PolyQuadMesh`, `~.Axes.pcolormesh`
        returns a `.QuadMesh`. The latter is more specialized for the given
        purpose and thus is faster. It should almost always be preferred.

        There is also a slight difference in the handling of masked arrays.
        Both `~.Axes.pcolor` and `~.Axes.pcolormesh` support masked arrays
        for *C*. However, only `~.Axes.pcolor` supports masked arrays for *X*
        and *Y*. The reason lies in the internal handling of the masked values.
        `~.Axes.pcolor` leaves out the respective polygons from the
        PolyQuadMesh. `~.Axes.pcolormesh` sets the facecolor of the masked
        elements to transparent. You can see the difference when using
        edgecolors. While all edges are drawn irrespective of masking in a
        QuadMesh, the edge between two adjacent masked quadrilaterals in
        `~.Axes.pcolor` is not drawn as the corresponding polygons do not
        exist in the PolyQuadMesh. Because PolyQuadMesh draws each individual
        polygon, it also supports applying hatches and linestyles to the collection.

        Another difference is the support of Gouraud shading in
        `~.Axes.pcolormesh`, which is not available with `~.Axes.pcolor`.

        Nr