fpolarplot

Plot symbolic expression or function in polar coordinates

Since R2024a

Syntax

fpolarplot(f)

fpolarplot(f,[a b])

fpolarplot(___,LineSpec)

fpolarplot(___,Name=Value)

fpolarplot(pax,___)

fp = fpolarplot(___)

Description

fpolarplot(f) plots the curve r = f(θ) in polar coordinates over the default interval 0 ≤ θ ≤ 2π.

fpolarplot(f,[a b]) plots r = f(θ) over the specified interval a ≤ θ ≤ b.

fpolarplot(___,LineSpec) specifies the line style, marker symbol, and line color. For example, "-r" plots a solid red line. Use this option after any of the input argument combinations in the previous syntaxes.

fpolarplot(___,Name=Value) specifies line properties using one or more name-value arguments. For example, LineWidth=2 specifies a line width of 2 points.

fpolarplot(pax,___) plots into the PolarAxes object specified by pax instead of the current axes (gca).

fp = fpolarplot(___) returns a FunctionLine object. Use the object to query and modify properties of the plotted line. For a list of properties, see FunctionLine Properties.

Examples

Polar Plot of Symbolic Expression

Create a polar plot of the expression $1+\cos \left(\mathit{t}\right)$ over the interval $$0\le \theta \le 2\pi$$.

syms t
expr = 1 + cos(t);
fpolarplot(expr)

Specify Plotting Interval

Plot$\mathit{f}\left(\mathit{t}\right)={\mathit{t}}^2$ over the interval $$-2\pi \le t\le 2\pi$$ by specifying the plotting interval as the second input to fpolarplot.

syms f(t)
f(t) = t^2;
fpolarplot(f(t),[-2*pi 2*pi])

Plot Negative Radius Values

Create a polar plot using negative radius values. By default, fpolarplot reflects negative values through the origin.

syms t
f = sin(t);
fpolarplot(f)

Change the limits of the $\mathit{r}$-axis so it ranges from –1 to 1.

rlim([-1 1])

Change Line Properties

Plot three curves in polar coordinates. Use a dash-dotted line for the first curve, a dashed line with a line width of 2 for the second curve, and a solid blue line for the third curve.

syms t
fpolarplot(t^(1/4),"-.")
hold on
fpolarplot(t^(2/3),"--",LineWidth=2)
fpolarplot(t,"-b")
legend
hold off

Alternatively, you can plot a vector of symbolic expressions by using a single fpolarplot command, and return an array of function line object handles.

syms t
figure
fp = fpolarplot([t^(1/4), t^(2/3), t])

fp = 
  3x1 FunctionLine array:

  FunctionLine
  FunctionLine
  FunctionLine

legend

You can access and modify properties of the function line object by using dot notation. For example, change the color, line style, and line width of each curve.

fp(1).LineStyle = "-.";
fp(2).LineStyle = "--";
fp(2).LineWidth = 2;
fp(3).Color = "blue";

Modify Polar Plot After Creation

Plot the curve $\mathit{r}=\sin \left(2\theta \right)\cos \left(2\theta \right)$ in polar coordinates, and return the function line object.

syms theta
r = sin(2*theta)*cos(2*theta);
fp = fpolarplot(r)

fp = 
  FunctionLine with properties:

     Function: cos(2*theta)*sin(2*theta)
        Color: [0 0.4470 0.7410]
    LineStyle: '-'
    LineWidth: 0.5000

  Use GET to show all properties

You can access and modify properties of the function line object by using dot notation. For example, change the color, line style, and line width.

fp.Color = "r";
fp.LineStyle = ":";
fp.LineWidth = 2;

Input Arguments

f — Expression or function to plot

symbolic expression | symbolic function | vector of symbolic expressions | vector of symbolic functions

Expression or function to plot, specified as a symbolic expression, symbolic function, vector of symbolic expressions, or vector of symbolic functions.

Example: syms t; f(t) = [t^(1/4); t^(2/3); t]

[a b] — Interval for polar angle

[0 2*pi] (default) | two-element vector | two-element symbolic vector

Interval for the polar angle θ, specified as a two-element vector or symbolic vector of the form [a b]. fpolarplot plots over the specified interval a ≤ θ ≤ b.

pax — PolarAxes object

PolarAxes object

PolarAxes object. You can modify the appearance and behavior of a PolarAxes object by setting its properties. For a list of properties, see PolarAxes Properties.

LineSpec — Line style, marker, and color

string scalar | character vector

Line style, marker, and color, specified as a string scalar or character vector 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 Style	Description	Resulting Line
"-"	Solid line
"--"	Dashed line
":"	Dotted line
"-."	Dash-dotted line

Marker	Description	Resulting Marker
"o"	Circle
"+"	Plus sign
"*"	Asterisk
"."	Point
"x"	Cross
"_"	Horizontal line
"|"	Vertical line
"square"	Square
"diamond"	Diamond
"^"	Upward-pointing triangle
"v"	Downward-pointing triangle
">"	Right-pointing triangle
"<"	Left-pointing triangle
"pentagram"	Pentagram
"hexagram"	Hexagram

Color Name	Short Name	RGB Triplet	Appearance
"red"	"r"	[1 0 0]
"green"	"g"	[0 1 0]
"blue"	"b"	[0 0 1]
"cyan"	"c"	[0 1 1]
"magenta"	"m"	[1 0 1]
"yellow"	"y"	[1 1 0]
"black"	"k"	[0 0 0]
"white"	"w"	[1 1 1]

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Example: fpolarplot(f,Marker="o",MarkerFaceColor="red")

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

Color — Line color

[0 0.4470 0.7410] (default) | RGB triplet | hexadecimal color code | "r" | "g" | "b" | ...

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 string scalar or character vector 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. Therefore, 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"

Example: "blue"

Example: [0 0 1]

Example: "#0000FF"

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.

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 — Marker symbol

"none" (default) | "o" | "+" | "*" | "." | ...

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.

Marker	Description	Resulting Marker
"o"	Circle
"+"	Plus sign
"*"	Asterisk
"."	Point
"x"	Cross
"_"	Horizontal line
"|"	Vertical line
"square"	Square
"diamond"	Diamond
"^"	Upward-pointing triangle
"v"	Downward-pointing triangle
">"	Right-pointing triangle
"<"	Left-pointing triangle
"pentagram"	Pentagram
"hexagram"	Hexagram
"none"	No markers	Not applicable

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 string scalar or character vector 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. Therefore, 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" 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 string scalar or character vector 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. Therefore, 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: [0.3 0.2 0.1]

Example: "green"

Example: "#D2F9A7"

MarkerSize — Marker size

6 (default) | positive value

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

Version History

Introduced in R2024a