# fplot

Plot expression or function

## Syntax

fplot(f)
fplot(f,xinterval)
fplot(funx,funy)
fplot(funx,funy,tinterval)
fplot(___,LineSpec)
fplot(___,Name,Value)
fplot(ax,___)
fp = fplot(___)
[x,y] = fplot(___)

## Description

example

fplot(f) plots the curve defined by the function y = f(x) over the default interval [-5 5] for x.

example

fplot(f,xinterval) plots over the specified interval. Specify the interval as a two-element vector of the form [xmin xmax].

example

fplot(funx,funy) plots the curve defined by x = funx(t) and y = funy(t) over the default interval [-5 5] for t.
fplot(funx,funy,tinterval) plots over the specified interval. Specify the interval as a two-element vector of the form [tmin tmax].
fplot(___,LineSpec) specifies the line style, marker symbol, and line color. For example, '-r' plots a red line. Use this option after any of the input argument combinations in the previous syntaxes. 

example

fplot(___,Name,Value) specifies line properties using one or more name-value pair arguments. For example, 'LineWidth',2 specifies a line width of 2 points.
fplot(ax,___) plots into the axes specified byax instead of the current axes (gca). Specify the axes as the first input argument.

example

fp = fplot(___) returns a FunctionLine object or a ParameterizedFunctionLine object, depending on the inputs. Use fp to query and modify properties of a specific line. For a list of properties, see FunctionLine Properties or ParameterizedFunctionLine Properties.
[x,y] = fplot(___) returns the abscissas and ordinates for the function without creating a plot. This syntax will be removed in a future release. Use the XData and YData properties of the line object, fp, instead. Notefplot no longer supports input arguments for specifying the error tolerance or the number of evaluation points. To specify the number of evaluation points, use the MeshDensity property. 

## Examples

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Plot sin(x) over the default x interval [-5 5].

fplot(@(x) sin(x))

Plot the parametric curve $x=cos\left(3t\right)$ and $y=sin\left(2t\right)$.

xt = @(t) cos(3*t); yt = @(t) sin(2*t); fplot(xt,yt)

Plot the piecewise function

$\begin{array}{cc}{e}^{x}& -3

Plot multiple lines using hold on. Specify the plotting intervals using the second input argument of fplot. Specify the color of the plotted lines as blue using 'b'. When you plot multiple lines in the same axes, the axis limits adjust to incorporate all the data.

fplot(@(x) exp(x),[-3 0],'b') hold on fplot(@(x) cos(x),[0 3],'b') hold off grid on

Plot three sine waves with different phases. For the first, use a line width of 2 points. For the second, specify a dashed red line style with circle markers. For the third, specify a cyan, dash-dotted line style with asterisk markers.

fplot(@(x) sin(x+pi/5),'Linewidth',2); hold on fplot(@(x) sin(x-pi/5),'--or'); fplot(@(x) sin(x),'-.*c') hold off

Plot sin(x) and assign the function line object to a variable.

fp = fplot(@(x) sin(x))

fp = FunctionLine with properties: Function: @(x)sin(x) Color: [0 0.4470 0.7410] LineStyle: '-' LineWidth: 0.5000 Show all properties 

Change the line to a dotted red line by using dot notation to set properties. Add cross markers and set the marker color to blue.

fp.LineStyle = ':'; fp.Color = 'r'; fp.Marker = 'x'; fp.MarkerEdgeColor = 'b';

Plot two lines using hold on.

fplot(@(x) sin(x)) hold on fplot(@(x) cos(x)) hold off

Plot $\mathrm{sin}\left(x\right)$ from $-2\pi$ to $2\pi$ using a function handle. Display the grid lines. Then, add a title and label the x-axis and y-axis.

fplot(@sin,[-2*pi 2*pi]) grid on title('sin(x) from -2\pi to 2\pi') xlabel('x'); ylabel('y');

Use gca to access the current axes object. Display tick marks along the x-axis at intervals of $\pi /2$. Format the x-axis tick values by setting the XTick and XTickLabel properties of the axes object. Similar properties exist for the y-axis.

ax = gca; ax.XTick = -2*pi:pi/2:2*pi; ax.XTickLabel = {'-2\pi','-3\pi/2','-\pi','-\pi/2','0','\pi/2','\pi','3\pi/2','2\pi'};

## Input Arguments

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Function to plot, specified as a function handle to a named or anonymous function.

Specify a function of the form y = f(x). The function must accept a vector input argument and return a vector output argument of the same size. Use array operators instead of matrix operators for the best performance. For example, use .* (times) instead of * (mtimes).

Note

Support for character vector inputs will be removed in a future release. Use function handles instead.

Example: f = @(x) sin(x);

Interval for x, specified as a two-element vector of the form [xmin xmax].

Parametric function for x coordinates, specified as a function handle to a named or anonymous function.

Specify a function of the form x = funx(t). The function must accept a vector input argument and return a vector output argument of the same size. Use array operators instead of matrix operators for the best performance. For example, use .* (times) instead of * (mtimes).

Example: funx = @(t) sin(2*t);

Parametric function for y coordinates, specified as a function handle to a named or anonymous function.

Specify a function of the form y = funy(t). The function must accept a vector input argument and return a vector output argument of the same size. Use array operators instead of matrix operators for the best performance. For example, use .* (times) instead of * (mtimes).

Example: funy = @(t) cos(3*t);

Interval for t, specified as a two-element vector of the form [tmin tmax].

Axes object. If you do not specify an axes object, then fplot uses the current axes (gca).

Line style, marker, and color, specified as a character vector or string containing symbols. The symbols can appear in any order. You do not need to specify all three characteristics (line style, marker, and color). For example, if you omit the line style and specify the marker, then the plot shows only the marker and no line.

Example: '--or' is a red dashed line with circle markers

Line StyleDescription
-Solid line
--Dashed line
:Dotted line
-.Dash-dot line
MarkerDescription
'o'Circle
'+'Plus sign
'*'Asterisk
'.'Point
'x'Cross
'_'Horizontal line
'|'Vertical line
's'Square
'd'Diamond
'^'Upward-pointing triangle
'v'Downward-pointing triangle
'>'Right-pointing triangle
'<'Left-pointing triangle
'p'Pentagram
'h'Hexagram
ColorDescription

y

yellow

m

magenta

c

cyan

r

red

g

green

b

blue

w

white

k

black

### 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: 'Marker','o','MarkerFaceColor','red'

The properties listed here are only a subset. For a complete list, see FunctionLine Properties or ParameterizedFunctionLine Properties.

Number of evaluation points, specified as a number. The default is 23. Because fplot uses adaptive evaluation, the actual number of evaluation points is greater.

Line 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 NameShort NameRGB TripletHexadecimal Color CodeAppearance
'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.

[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'

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

Line StyleDescriptionResulting Line
'-'Solid line

'--'Dashed line

':'Dotted line

'-.'Dash-dotted line

'none'No lineNo line

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.

The line width cannot be thinner than the width of a pixel. If you set the line width to a value that is less than the width of a pixel on your system, the line displays as one pixel wide.

Marker symbol, specified as one of the values listed in this table. By default, the object does not display markers. Specifying a marker symbol adds markers at each data point or vertex.

ValueDescription
'o'Circle
'+'Plus sign
'*'Asterisk
'.'Point
'x'Cross
'_'Horizontal line
'|'Vertical line
'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

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 NameShort NameRGB TripletHexadecimal Color CodeAppearance
'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 applicableNot applicableNot applicableNo color

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

[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'

Marker fill color, specified as 'auto', an RGB triplet, a hexadecimal color code, a color name, or a short name. The 'auto' value uses the same color as the MarkerEdgeColor 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 NameShort NameRGB TripletHexadecimal Color CodeAppearance
'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 applicableNot applicableNot applicableNo color

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

[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: [0.3 0.2 0.1]

Example: 'green'

Example: '#D2F9A7'

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

## Output Arguments

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One or more FunctionLine or ParameterizedFunctionLine objects, returned as a scalar or a vector.

• If you use the fplot(f) syntax or a variation of this syntax, then fplot returns FunctionLine objects.

• If you use the fplot(funx,funy) syntax or a variation of this syntax, then fplot returns ParameterizedFunctionLine objects.

You can use these objects to query and modify properties of a specific line. For a list of properties, see FunctionLine Properties and ParameterizedFunctionLine Properties.

## Tips

• Use element-wise operators for the best performance and to avoid a warning message. For example, use x.*y instead of x*y. For more information, see Array vs. Matrix Operations.

• When you zoom in on the chart, fplot replots the data, which can reveal hidden details.

## Extended Capabilities

Introduced before R2006a