Note: This page has been translated by MathWorks. Please click here

To view all translated materials including this page, select Japan from the country navigator on the bottom of this page.

To view all translated materials including this page, select Japan from the country navigator on the bottom of this page.

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.

Was this topic helpful?