surf

Surface plot

Syntax

surf(X,Y,Z)

surf(X,Y,Z,C)

surf(Z)

surf(Z,C)

surf(ax,___)

surf(___,Name,Value)

s = surf(___)

Description

surf(X,Y,Z) creates a three-dimensional surface plot, which is a three-dimensional surface that has solid edge colors and solid face colors. The function plots the values in matrix Z as heights above a grid in the x-y plane defined by X and Y. The color of the surface varies according to the heights specified by Z.

surf(X,Y,Z,C) additionally specifies the surface color.

surf(Z) creates a surface plot and uses the column and row indices of the elements in Z as the x- and y-coordinates.

surf(Z,C) additionally specifies the surface color.

surf(ax,___) plots into the axes specified by ax instead of the current axes. Specify the axes as the first input argument.

surf(___,Name,Value) specifies surface properties using one or more name-value pair arguments. For example, 'FaceAlpha',0.5 creates a semitransparent surface.

s = surf(___) returns the chart surface object. Use s to modify the surface after it is created. For a list of properties, see Surface Properties.

Examples

Create Surface Plot

Create three matrices of the same size. Then plot them as a surface. The surface plot uses Z for both height and color.

[X,Y] = meshgrid(1:0.5:10,1:20);
Z = sin(X) + cos(Y);
surf(X,Y,Z)

Specify Colormap Colors for Surface Plot

Specify the colors for a surface plot by including a fourth matrix input, C. The surface plot uses Z for height and C for color. Specify the colors using a colormap, which uses single numbers to stand for colors on a spectrum. When you use a colormap, C is the same size as Z. Add a color bar to the graph to show how the data values in C correspond to the colors in the colormap.

[X,Y] = meshgrid(1:0.5:10,1:20);
Z = sin(X) + cos(Y);
C = X.*Y;
surf(X,Y,Z,C)
colorbar

Specify True Colors for Surface Plot

Specify the colors for a surface plot by including a fourth matrix input, CO. The surface plot uses Z for height and CO for color. Specify the colors using truecolor, which uses triplets of numbers to stand for all possible colors. When you use truecolor, if Z is m-by-n, then CO is m-by-n-by-3. The first page of the array indicates the red component for each color, the second page indicates the green component, and the third page indicates the blue component.

[X,Y,Z] = peaks(25);
CO(:,:,1) = zeros(25); % red
CO(:,:,2) = ones(25).*linspace(0.5,0.6,25); % green
CO(:,:,3) = ones(25).*linspace(0,1,25); % blue
surf(X,Y,Z,CO)

Modify Surface Plot Appearance

Create a semitransparent surface by specifying the FaceAlpha name-value pair with 0.5 as the value. To allow further modifications, assign the surface object to the variable s.

[X,Y] = meshgrid(-5:.5:5);
Z = Y.*sin(X) - X.*cos(Y);
s = surf(X,Y,Z,'FaceAlpha',0.5)

s = 
  Surface with properties:

       EdgeColor: [0 0 0]
       LineStyle: '-'
       FaceColor: 'flat'
    FaceLighting: 'flat'
       FaceAlpha: 0.5000
           XData: [21x21 double]
           YData: [21x21 double]
           ZData: [21x21 double]
           CData: [21x21 double]

  Show all properties

Use s to access and modify properties of the surface object after it is created. For example, hide the edges by setting the EdgeColor property.

s.EdgeColor = 'none';

Input Arguments

X — x-coordinates

matrix | vector

x-coordinates, specified as a matrix the same size as Z, or as a vector with length n, where [m,n] = size(Z). If you do not specify values for X and Y, surf uses the vectors (1:n) and (1:m).

You can use the meshgrid function to create X and Y matrices.

The XData property of the Surface object stores the x-coordinates.

Example: X = 1:10

Example: X = [1 2 3; 1 2 3; 1 2 3]

Example: [X,Y] = meshgrid(-5:0.5:5)

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | categorical | datetime | duration

Y — y-coordinates

matrix | vector

y-coordinates, specified as a matrix the same size as Z or as a vector with length m, where [m,n] = size(Z). If you do not specify values for X and Y, surf uses the vectors (1:n) and (1:m).

You can use the meshgrid function to create the X and Y matrices.

The YData property of the surface object stores the y -coordinates.

Example: Y = 1:10

Example: Y = [1 1 1; 2 2 2; 3 3 3]

Example: [X,Y] = meshgrid(-5:0.5:5)

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | categorical | datetime | duration

Z — z-coordinates

matrix

z-coordinates, specified as a matrix. Z must have at least two rows and two columns.

Z specifies the height of the surface plot at each x-y coordinate. If you do not specify the colors, then Z also specifies the surface colors.

The ZData property of the surface object stores the z -coordinates.

Example: Z = [1 2 3; 4 5 6]

Example: Z = sin(x) + cos(y)

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | categorical | datetime | duration

C — Color array

matrix | m-by-n-by-3 array of RGB triplets

Color array, specified as an m-by-n matrix of colormap indices or as an m-by-n-by-3 array of RGB triplets, where Z is m-by-n.

• To use colormap colors, specify C as a matrix. For each grid point on the surface, C indicates a color in the colormap. The CDataMapping property of the surface object controls how the values in C correspond to colors in the colormap.

• To use truecolor colors, specify C as an array of RGB triplets.

For more information, see Differences Between Colormaps and Truecolor.

The CData property of the surface object stores the color array. For additional control over the surface coloring, use the FaceColor and EdgeColor properties.

ax — Axes to plot in

axes object

Axes to plot in, specified as an axes object. If you do not specify the axes, then surf plots into the current axes.

Name-Value Pair Arguments

Specify optional comma-separated pairs of Name,Value arguments. Name is the argument name and Value is the corresponding value. Name must appear inside quotes. You can specify several name and value pair arguments in any order as Name1,Value1,...,NameN,ValueN.

Example: surf(X,Y,Z,'FaceAlpha',0.5,'EdgeColor','none') creates a semitransparent surface with no edges drawn.

Note

The properties listed here are only a subset. For a full list, see Surface Properties.

'EdgeColor' — Edge line color

[0 0 0] (default) | 'none' | 'flat' | 'interp' | RGB triplet | hexadecimal color code | 'r' | 'g' | 'b' | ...

Edge line color, specified as one of the values listed here. The default color of [0 0 0] corresponds to black edges.

Value	Description
'none'	Do not draw the edges.
'flat'	Use a different color for each edge based on the values in the CData property. First you must specify the CData property as a matrix the same size as ZData. The color value at the first vertex of each face (in the positive x and y directions) determines the color for the adjacent edges. You cannot use this value when the EdgeAlpha property is set to 'interp'.
'interp'	Use interpolated coloring for each edge based on the values in the CData property. First you must specify the CData property as a matrix the same size as ZData. The color varies across each edge by linearly interpolating the color values at the vertices. You cannot use this value when the EdgeAlpha property is set to 'flat'.
RGB triplet, hexadecimal color code, or color name	Use the specified color for all the edges. This option does not use the color values in the CData property.

RGB triplets and hexadecimal color codes are useful for specifying custom colors.

• An RGB triplet is a three-element row vector whose elements specify the intensities of the red, green, and blue components of the color. The intensities must be in the range [0,1]; for example, [0.4 0.6 0.7].

• A hexadecimal color code is a character vector or a string scalar that starts with a hash symbol (#) followed by three or six hexadecimal digits, which can range from 0 to F. The values are not case sensitive. Thus, the color codes '#FF8800', '#ff8800', '#F80', and '#f80' are equivalent.

Alternatively, you can specify some common colors by name. This table lists the named color options, the equivalent RGB triplets, and hexadecimal color codes.

Color Name	Short Name	RGB Triplet	Hexadecimal Color Code	Appearance
'red'	'r'	[1 0 0]	'#FF0000'
'green'	'g'	[0 1 0]	'#00FF00'
'blue'	'b'	[0 0 1]	'#0000FF'
'cyan'	'c'	[0 1 1]	'#00FFFF'
'magenta'	'm'	[1 0 1]	'#FF00FF'
'yellow'	'y'	[1 1 0]	'#FFFF00'
'black'	'k'	[0 0 0]	'#000000'
'white'	'w'	[1 1 1]	'#FFFFFF'

Here are the RGB triplets and hexadecimal color codes for the default colors MATLAB^® uses in many types of plots.

RGB Triplet	Hexadecimal Color Code	Appearance
[0 0.4470 0.7410]	'#0072BD'
[0.8500 0.3250 0.0980]	'#D95319'
[0.9290 0.6940 0.1250]	'#EDB120'
[0.4940 0.1840 0.5560]	'#7E2F8E'
[0.4660 0.6740 0.1880]	'#77AC30'
[0.3010 0.7450 0.9330]	'#4DBEEE'
[0.6350 0.0780 0.1840]	'#A2142F'

'LineStyle' — Line style

'-' (default) | '--' | ':' | '-.' | 'none'

Line style, specified as one of the options listed in this table.

Line Style	Description	Resulting Line
'-'	Solid line
'--'	Dashed line
':'	Dotted line
'-.'	Dash-dotted line
'none'	No line	No line

'FaceColor' — Face color

'flat' (default) | 'interp' | 'none' | 'texturemap' | RGB triplet | hexadecimal color code | 'r' | 'g' | 'b' | ...

Face color, specified as one of the values in this table.

Value	Description
'flat'	Use a different color for each face based on the values in the CData property. First you must specify the CData property as a matrix the same size as ZData. The color value at the first vertex of each face (in the positive x and y directions) determines the color for the entire face. You cannot use this value when the FaceAlpha property is set to 'interp'.
'interp'	Use interpolated coloring for each face based on the values in the CData property. First you must specify the CData property as a matrix the same size as ZData. The color varies across each face by interpolating the color values at the vertices. You cannot use this value when the FaceAlpha property is set to 'flat'.
RGB triplet, hexadecimal color code, or color name	Use the specified color for all the faces. This option does not use the color values in the CData property.
'texturemap'	Transform the color data in CData so that it conforms to the surface.
'none'	Do not draw the faces.

RGB triplets and hexadecimal color codes are useful for specifying custom colors.

• An RGB triplet is a three-element row vector whose elements specify the intensities of the red, green, and blue components of the color. The intensities must be in the range [0,1]; for example, [0.4 0.6 0.7].

• A hexadecimal color code is a character vector or a string scalar that starts with a hash symbol (#) followed by three or six hexadecimal digits, which can range from 0 to F. The values are not case sensitive. Thus, the color codes '#FF8800', '#ff8800', '#F80', and '#f80' are equivalent.

Alternatively, you can specify some common colors by name. This table lists the named color options, the equivalent RGB triplets, and hexadecimal color codes.

Color Name	Short Name	RGB Triplet	Hexadecimal Color Code	Appearance
'red'	'r'	[1 0 0]	'#FF0000'
'green'	'g'	[0 1 0]	'#00FF00'
'blue'	'b'	[0 0 1]	'#0000FF'
'cyan'	'c'	[0 1 1]	'#00FFFF'
'magenta'	'm'	[1 0 1]	'#FF00FF'
'yellow'	'y'	[1 1 0]	'#FFFF00'
'black'	'k'	[0 0 0]	'#000000'
'white'	'w'	[1 1 1]	'#FFFFFF'

Here are the RGB triplets and hexadecimal color codes for the default colors MATLAB uses in many types of plots.

RGB Triplet	Hexadecimal Color Code	Appearance
[0 0.4470 0.7410]	'#0072BD'
[0.8500 0.3250 0.0980]	'#D95319'
[0.9290 0.6940 0.1250]	'#EDB120'
[0.4940 0.1840 0.5560]	'#7E2F8E'
[0.4660 0.6740 0.1880]	'#77AC30'
[0.3010 0.7450 0.9330]	'#4DBEEE'
[0.6350 0.0780 0.1840]	'#A2142F'

'FaceAlpha' — Face transparency

1 (default) | scalar in range [0,1] | 'flat' | 'interp' | 'texturemap'

Face transparency, specified as one of these values:

• Scalar in range [0,1] — Use uniform transparency across all the faces. A value of 1 is fully opaque and 0 is completely transparent. Values between 0 and 1 are semitransparent. This option does not use the transparency values in the AlphaData property.

• 'flat' — Use a different transparency for each face based on the values in the AlphaData property. The transparency value at the first vertex determines the transparency for the entire face. First you must specify the AlphaData property as a matrix the same size as the ZData property. The FaceColor property also must be set to 'flat'.

• 'interp' — Use interpolated transparency for each face based on the values in AlphaData property. The transparency varies across each face by interpolating the values at the vertices. First you must specify the AlphaData property as a matrix the same size as the ZData property. The FaceColor property also must be set to 'interp'.

• 'texturemap' — Transform the data in AlphaData so that it conforms to the surface.

'FaceLighting' — Effect of light objects on faces

'flat' (default) | 'gouraud' | 'none'

Effect of light objects on faces, specified as one of these values:

• 'flat' — Apply light uniformly across each face. Use this value to view faceted objects.

• 'gouraud' — Vary the light across the faces. Calculate the light at the vertices and then linearly interpolate the light across the faces. Use this value to view curved surfaces.

• 'none' — Do not apply light from light objects to the faces.

To add a light object to the axes, use the light function.

Note

The 'phong' value has been removed. Use 'gouraud' instead.

Extended Capabilities

GPU Arrays

Accelerate code by running on a graphics processing unit (GPU) using Parallel Computing Toolbox™.

Usage notes and limitations:

• This function accepts GPU arrays, but does not run on a GPU.

For more information, see Run MATLAB Functions on a GPU (Parallel Computing Toolbox).

Distributed Arrays

Partition large arrays across the combined memory of your cluster using Parallel Computing Toolbox™.

Usage notes and limitations:

• This function operates on distributed arrays, but executes in the client MATLAB.

For more information, see Run MATLAB Functions with Distributed Arrays (Parallel Computing Toolbox).