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Contour plot of matrix

`contour(Z)`

contour(Z,n)

contour(Z,v)

contour(X,Y,Z)

contour(X,Y,Z,n)

contour(X,Y,Z,v)

contour(...,LineSpec)

contour(...,Name,Value)

contour(ax,...)

[C,h] = contour(...)

A contour plot displays isolines of matrix `Z`

.
Label the contour lines using `clabel`

.

`contour(Z)`

draws a contour
plot of matrix `Z`

, where `Z`

is
interpreted as heights with respect to the *x*-*y* plane. `Z`

must
be at least a 2-by-2 matrix that contains at least two different values.
The *x* values correspond to the column indices
of `Z`

and the *y* values correspond
to the row indices of `Z`

. The contour levels are
chosen automatically.

`contour(Z,n)`

draws a contour
plot of matrix `Z`

with `n`

contour
levels where `n`

is a scalar. The contour levels
are chosen automatically.

`contour(Z,v)`

draws a contour
plot of matrix `Z`

with contour lines at the data
values specified in the monotonically increasing vector `v`

.
To display a single contour line at a particular value, define `v`

as
a two-element vector with both elements equal to the desired contour
level. For example, to draw contour lines at level `k`

,
use `contour(Z,[k k])`

. Specifying the vector `v`

sets
the `LevelListMode`

property
to manual.

`contour(X,Y,Z)`

, `contour(X,Y,Z,n)`

,
and `contour(X,Y,Z,v)`

draw contour plots of `Z`

using `X`

and `Y`

to
determine the *x* and *y* values.

If

`X`

and`Y`

are vectors, then`length(X)`

must equal`size(Z,2)`

and`length(Y)`

must equal`size(Z,1)`

. The vectors must be strictly increasing or strictly decreasing and cannot contain any repeated values.If

`X`

and`Y`

are matrices, then their sizes must equal the size of`Z`

. Typically, you should set`X`

and`Y`

so that the columns are strictly increasing or strictly decreasing and the rows are uniform (or the rows are strictly increasing or strictly decreasing and the columns are uniform).

If `X`

or `Y`

is
irregularly spaced, then `contour`

calculates contours
using a regularly spaced contour grid, and then transforms the data
to `X`

or `Y`

.

`contour(...,LineSpec)`

draws
the contours using the line type and color specified by `LineSpec`

. `contour`

ignores
marker symbols.

`contour(...,Name,Value)`

specifies
contour properties using one or more property name, property value
pairs. `Name`

is the property name and must appear
inside single quotes (`''`

). `Value`

is
the corresponding value. For example, `'LineWidth',2`

sets
the contour line width to 2. For a list of contour property names
and values, see Contour Properties.

`contour(ax,...)`

plots into
the axes specified by `ax`

instead of the current
axes (`gca`

).

`[C,h] = contour(...)`

returns
the contour matrix `C`

containing the data that defines
the contour lines, and the `Contour`

object `h`

.
The `ContourMatrix`

property
for the `Contour`

object also contains the contour
matrix. The `clabel`

function
uses the contour matrix to label the contour lines.

Use `Contour`

object properties to control the
contour plot appearance. For a list, see Contour Properties.

The

`contour`

function cannot determine if there are discontinuities in the input data. Add`NaN`

values to the data to prevent drawing the contour lines in those regions.

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