stem

Plot discrete sequence data

Syntax

stem(Y)

stem(X,Y)

stem(___,'filled')

stem(___,LineSpec)

stem(___,Name,Value)

stem(ax,___)

h = stem(___)

Description

stem(Y) plots the data sequence, Y, as stems that extend from a baseline along the x-axis. The data values are indicated by circles terminating each stem.

• If Y is a vector, then the x-axis scale ranges from 1 to length(Y).

• If Y is a matrix, then stem plots all elements in a row against the same x value, and the x-axis scale ranges from 1 to the number of rows in Y.

stem(X,Y) plots the data sequence, Y, at values specified by X. The X and Y inputs must be vectors or matrices of the same size. Additionally, X can be a row or column vector and Y must be a matrix with length(X) rows.

• If X and Y are both vectors, then stem plots entries in Y against corresponding entries in X.

• If X is a vector and Y is a matrix, then stem plots each column of Y against the set of values specified by X, such that all elements in a row of Y are plotted against the same value.

• If X and Y are both matrices, then stem plots columns of Y against corresponding columns of X.

stem(___,'filled') fills the circles. Use this option with any of the input argument combinations in the previous syntaxes.

stem(___,LineSpec) specifies the line style, marker symbol, and color.

stem(___,Name,Value) modifies the stem chart using one or more Name,Value pair arguments.

stem(ax,___) plots into the axes specified by ax instead of into the current axes (gca). The option, ax, can precede any of the input argument combinations in the previous syntaxes.

h = stem(___) returns a vector of Stem objects in h. Use h to modify the stem chart after it is created.

Examples

Plot Single Data Series

Create a stem plot of 50 data values between $$-2\pi$$ and $$2\pi$$.

figure
Y = linspace(-2*pi,2*pi,50);
stem(Y)

Data values are plotted as stems extending from the baseline and terminating at the data value. The length of Y automatically determines the position of each stem on the x-axis.

Plot Multiple Data Series

Plot two data series using a two-column matrix.

figure
X = linspace(0,2*pi,50)';
Y = [cos(X), 0.5*sin(X)];
stem(Y)

Each column of Y is plotted as a separate series, and entries in the same row of Y are plotted against the same x value. The number of rows in Y automatically generates the position of each stem on the x-axis.

Plot Single Data Series at Specified x values

Plot 50 data values of cosine evaluated between 0 and $$2\pi$$ and specify the set of x values for the stem plot.

figure
X = linspace(0,2*pi,50)';
Y = cos(X);
stem(X,Y)

The first vector input determines the position of each stem on the x-axis.

Plot Multiple Data Series at Specified x values

Plot 50 data values of sine and cosine evaluated between 0 and $$2\pi$$ and specify the set of x values for the stem plot.

figure
X = linspace(0,2*pi,50)';
Y = [cos(X), 0.5*sin(X)];
stem(X,Y)

The vector input determines the x-axis positions for both data series.

Plot Multiple Data Series at Unique Sets of x values

Plot 50 data values of sine and cosine evaluated at different sets of x values. Specify the corresponding sets of x values for each series.

figure
x1 = linspace(0,2*pi,50)';
x2 = linspace(pi,3*pi,50)';
X = [x1, x2];
Y = [cos(x1), 0.5*sin(x2)];
stem(X,Y)

Each column of X is plotted against the corresponding column of Y.

Fill in Plot Markers

Create a stem plot and fill in the circles that terminate each stem.

X = linspace(0,10,20)';
Y = (exp(0.25*X));
stem(X,Y,'filled')

Specify Stem and Marker Options

Create a stem plot and set the line style to a dotted line, the marker symbols to diamonds, and the color to red using the LineSpec option.

figure
X = linspace(0,2*pi,50)';
Y = (exp(X).*sin(X));
stem(X,Y,':diamondr')

To color the inside of the diamonds, use the 'fill' option.

Specify Additional Stem and Marker Options

Create a stem plot and set the line style to a dot-dashed line, the marker face color to red, and the marker edge color to green using Name,Value pair arguments.

figure
X = linspace(0,2*pi,25)';
Y = (cos(2*X));
stem(X,Y,'LineStyle','-.',...
     'MarkerFaceColor','red',...
     'MarkerEdgeColor','green')

The stem remains the default color.

Specify Axes for Stem Plot

Create a figure with two subplots and return the handles to each axes, s(1) and s(2). Create a stem plot in the lower subplot by referring to its axes handle, s(2).

figure
s(1) = subplot(2,1,1);
s(2) = subplot(2,1,2);  

X = 0:25;
Y = [exp(0.1*X); -exp(.05*X)]';
stem(s(2),X,Y)

Modify Stem Series After Creation

Create a stem plot.

X = 0:25;
Y = [cos(X); exp(0.05*X)]';
h = stem(X,Y);

The stem function creates a stem series object for each column of data. The output argument, h, contains the two stem series objects.

Set the first stem series color to green. Change the markers of the second stem series to squares. Starting in R2014b, you can use dot notation to set properties. If you are using an earlier release, use the set function instead.

h(1).Color = 'green';
h(2).Marker = 'square';

Adjust Baseline Properties

Create a stem plot and change properties of the baseline.

X = linspace(0,2*pi,50);
Y = exp(0.3*X).*sin(3*X);
h = stem(X,Y);

Change the line style of the baseline. Starting in R2014b, you can use dot notation to set properties. If you are using an earlier release, use the set function instead.

hbase = h.BaseLine; 
hbase.LineStyle = '--';

Hide the baseline by setting its Visible property to 'off' .

hbase.Visible = 'off';

Change Baseline Level

Create a stem plot with a baseline level at 2.

X = linspace(0,2*pi,50)';
Y = (exp(0.3*X).*sin(3*X));
stem(X,Y,'BaseValue',2);

Input Arguments

Y — Data sequence to display

vector or matrix

Data sequence to display, specified as a vector or matrix. When Y is a vector, stem creates one Stem object. When Y is a matrix, stem creates a separate Stem object for each column.

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

X — Locations to plot data values in Y

vector or matrix

Locations to plot data values in Y, specified as a vector or matrix. When Y is a vector, X must be a vector of the same size. When Y is a matrix, X must be a matrix of the same size, or a vector whose length equals the number of rows in Y.

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

LineSpec — Line style, marker, and color

character vector | string

Line style, marker, and color, specified as a character vector or string. For more information, see LineSpec.

Example: ':*r'

ax — Axes object

Axes object

Axes object. If you do not specify the axes, then stem 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: 'LineStyle',':','MarkerFaceColor','red' plots the stem as a dotted line and colors the marker face red.

The Stem properties listed here are only a subset. For a complete list, see Stem Properties.

'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

'LineWidth' — Line width

0.5 (default) | positive value

Line width, specified as a positive value in points, where 1 point = 1/72 of an inch. If the line has markers, then the line width also affects the marker edges.

'Color' — Stem color

[0 0 0] (default) | RGB triplet | hexadecimal color code | 'r' | 'g' | 'b' | ...

Stem color, specified as an RGB triplet, a hexadecimal color code, a color name, or a short name.

For a custom color, specify an RGB triplet or a hexadecimal color code.

• 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'
'none'	Not applicable	Not applicable	Not applicable	No color

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'

Example: 'blue'

Example: [0 0 1]

Example: '#0000FF'

'Marker' — Marker symbol

'o' (default) | '+' | '*' | '.' | 'x' | ...

Marker symbol, specified as one of the markers listed in this table.

Value	Description
'o'	Circle
'+'	Plus sign
'*'	Asterisk
'.'	Point
'x'	Cross
'square' or 's'	Square
'diamond' or 'd'	Diamond
'^'	Upward-pointing triangle
'v'	Downward-pointing triangle
'>'	Right-pointing triangle
'<'	Left-pointing triangle
'pentagram' or 'p'	Five-pointed star (pentagram)
'hexagram' or 'h'	Six-pointed star (hexagram)
'none'	No markers

Example: '+'

Example: 'diamond'

'MarkerSize' — Marker size

6 (default) | positive value

Marker size, specified as a positive value in points, where 1 point = 1/72 of an inch.

'MarkerEdgeColor' — Marker outline color

'auto' (default) | RGB triplet | hexadecimal color code | 'r' | 'g' | 'b' | ...

Marker outline color, specified as 'auto', an RGB triplet, a hexadecimal color code, a color name, or a short name. The default value of 'auto' uses the same color as the Color property.

For a custom color, specify an RGB triplet or a hexadecimal color code.

• 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'
'none'	Not applicable	Not applicable	Not applicable	No color

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'

'MarkerFaceColor' — Marker fill color

'none' (default) | 'auto' | RGB triplet | hexadecimal color code | 'r' | 'g' | 'b' | ...

Marker fill color, specified as 'auto', an RGB triplet, a hexadecimal color code, a color name, or a short name. The 'auto' option uses the same color as the Color property of the parent axes. If you specify 'auto' and the axes plot box is invisible, the marker fill color is the color of the figure.

For a custom color, specify an RGB triplet or a hexadecimal color code.

• 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'
'none'	Not applicable	Not applicable	Not applicable	No color

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'

Output Arguments

h — Stem objects

Stem objects

Stem objects. These are unique identifiers, which you can use to modify the properties of a specific Stem object after it is created.

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).