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Pseudocolor (checkerboard) plot

`pcolor(C)`

pcolor(X,Y,C)

pcolor(axes_handles,...)

h = pcolor(...)

A pseudocolor plot is a rectangular array of cells with colors
determined by `C`

. MATLAB^{®} creates a pseudocolor
plot using each set of four adjacent points in `C`

to
define a surface rectangle (i.e., cell).

The default `shading`

is `faceted`

, which
colors each cell with a single color. The last row and column of `C`

are not
used in this case. With `shading`

`interp`

, each cell is colored by interpolating the colors at its four
vertices, using all elements of `C`

.

The minimum and maximum elements of `C`

are
assigned the first and last colors in the colormap. Colors for the
remaining elements in `C`

are determined by a linear
mapping from value to colormap element.

`pcolor(C)`

draws a pseudocolor
plot. The elements of `C`

are linearly mapped to
an index into the current colormap. The mapping from `C`

to
the current colormap is defined by `colormap`

and `caxis`

.

`pcolor(X,Y,C)`

draws a
pseudocolor plot of the elements of `C`

at the locations
specified by `X`

and `Y`

. The plot
is a logically rectangular, two-dimensional grid with vertices at
the points `[X(i,j), Y(i,j)]`

. `X`

and `Y`

are
vectors or matrices that specify the spacing of the grid lines. If `X`

and `Y`

are
vectors, `X`

corresponds to the columns of `C`

and `Y`

corresponds
to the rows. If `X`

and `Y`

are
matrices, they must be the same size as `C`

.

`pcolor(axes_handles,...)`

plots into the axes with handle `axes_handle`

instead
of the current axes (`gca`

).

`h = pcolor(...)`

returns
a handle to a `surface`

graphics
object.

A pseudocolor plot is a flat surface plot viewed from above. `pcolor(X,Y,C)`

is
the same as viewing `surf(X,Y,zeros(size(X)),C)`

using ```
view([0
90])
```

.

When you use `shading`

`faceted`

or `shading`

`flat`

,
the constant color of each cell is the color associated with the corner
having the smallest *x*-*y* coordinates.
Therefore, `C(i,j)`

determines the color of the cell
in the *i*th row and *j*th column.
The last row and column of `C`

are not used.

When you use `shading interp`

, each cell's color results from an
interpolation of the colors at its four vertices, and all elements of `C`

are
used.

Use the `pcolor`

, `image`

,
or `imagesc`

function to display image data. Each
function displays a rectangular array of cells and uses `C`

to
determine the colors.

`pcolor(C)`

uses the values in`C`

to define the vertex colors by scaling the values to map to the full range of the colormap. The size of`C`

determines the number of vertices.`pcolor`

determines the cell colors using the colors defined at the cell vertices.`image(C)`

uses`C`

to define the cell colors by mapping the values directly into the colormap. The size of`C`

determines the number of cells.`imagesc(C)`

uses`C`

to define the cell colors by scaling the values to map to the full range of the colormap. The size of`C`

determines the number of cells.

`pcolor(X,Y,C)`

can produce parametric grids,
which is not possible with `image`

or `imagesc`

.

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