pie

Pie chart

• 

Syntax

pie(X)

pie(X,explode)

pie(X,labels)

pie(X,explode,labels)

pie(ax,___)

p = pie(___)

Description

pie(X) draws a pie chart using the data in X. Each slice of the pie chart represents an element in X.

• If sum(X) ≤ 1, then the values in X directly specify the areas of the pie slices. pie draws only a partial pie if sum(X) < 1.

• If sum(X) > 1, then pie normalizes the values by X/sum(X) to determine the area of each slice of the pie.

• If X is of data type categorical, the slices correspond to categories. The area of each slice is the number of elements in the category divided by the number of elements in X.

pie(X,explode) offsets slices from the pie. explode is a vector or matrix of zeros and nonzeros that correspond to X. The pie function offsets slices for the nonzero elements only in explode.

If X is of data type categorical, then explode can be a vector of zeros and nonzeros corresponding to categories, or a cell array of the names of categories to offset.

pie(X,labels) specifies options for labelling the pie slices. In this case, X must be numeric.

pie(X,explode,labels) offsets slices and specifies the text labels. X can be numeric or categorical.

pie(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.

p = pie(___) returns a vector of patch and text graphics objects. The input can be any of the input argument combinations in the previous syntaxes.

Examples

Create Pie Chart with Offset Slices

Create a pie chart of vector X.

X = [1 3 0.5 2.5 2];
pie(X)

Offset the second and fourth pie slices by setting the corresponding explode elements to 1.

explode = [0 1 0 1 0];
pie(X,explode)

Specify Text Labels for Pie Chart

Create a pie chart of vector X and label the slices.

X = 1:3;
labels = {'Taxes','Expenses','Profit'};
pie(X,labels)

Modify Text Label for Pie Chart

Create a labeled pie chart, and then modify the color and font size of the text labels.

X = 1:3;
labels = {'Taxes','Expenses','Profit'};
p = pie(X,labels)

p = 
  1x6 graphics array:

    Patch    Text     Patch    Text     Patch    Text 

Get the text object for the label 'Profit'. Change its color and font size. Use dot notation to set properties.

t = p(6);
t.BackgroundColor = 'cyan';
t.EdgeColor = 'red';
t.FontSize = 14;

Specify Format for Percentage Labels

Create a pie chart, and specify a format expression to display each label with three digits after the decimal point. To include a percent sign in the labels, specify '%%' at the end of the expression.

X = [1/3 2/3];
pie(X,'%.3f%%')

Plot Partial Pie Chart

Create a pie chart of vector X where the sum of the elements is less than 1.

X = [0.19 0.22 0.41];
pie(X)

pie draws a partial pie because the sum of the elements is less than 1.

Compare Two Pie Charts

Create vectors y2010 and y2011, that contain financial data for two years. Then create a cell array containing the labels for the values.

y2010 = [50 0 100 95];
y2011 = [65 22 97 120];
labels = {'Investments','Cash','Operations','Sales'};

Create a 1-by-2 tiled chart layout, and display two pie charts that each have a title. Then display a shared legend in the east tile of the layout. To do this, call the legend function with a return argument to store the legend object. Then move the legend to the east tile by setting the Layout.Tile property to 'east'.

t = tiledlayout(1,2,'TileSpacing','compact');

% Create pie charts
ax1 = nexttile;
pie(ax1,y2010)
title('2010')

ax2 = nexttile;
pie(ax2,y2011)
title('2011')

% Create legend
lgd = legend(labels);
lgd.Layout.Tile = 'east';

Plot Categorical Pie Chart with Offsets

Plot a categorical pie chart with offset slices corresponding to categories.

X = categorical({'North','South','North','East','South','West'});
explode = {'North','South'};
pie(X,explode)

Now, use a logical vector to offset the same slices.

explode = [0 1 1 0];
pie(X,explode)

Plot Categorical Pie Chart with Labels

Plot a categorical pie chart without any offset slices and label the slices. When X is of data type categorical you must specify the input argument explode. To specify labels without any offset slices, specify explode as an empty cell array, and labels as the labels.

X = categorical({'North','South','North','East','South','West'});
explode = {};
labels = {'E','N','S','W'};
pie(X,explode,labels)

Now, offset a slice and label all slices.

X = categorical({'North','South','North','East','South','West'});
explode = {'West'};
labels = {'E','N','S','W'};
pie(X,explode,labels)

Input Arguments

X — Input array

vector | matrix

Input vector or matrix.

• If X is numeric, then all values in X must be finite.

• If X is categorical, then pie ignores undefined elements.

Data Types: double|categorical

explode — Offset slices

numeric vector or matrix | logical vector or matrix | string array | cell array of character vectors

Offset slices, specified as a numeric vector or matrix, logical vector or matrix, string array, or cell array of character vectors.

• If X is numeric, then explode must be a logical or numeric vector or matrix of zeros and nonzeros that correspond to X. A true (nonzero) value offsets the corresponding slice from the center of the pie chart, so that X(i,j) is offset from the center if explode(i,j) is nonzero. explode must be the same size as X.

• If X is categorical, then explode can be a string array or cell array of category names. pie offsets slices corresponding to categories in explode.

• If X is categorical, then explode also can be a logical or numeric vector with elements that correspond to each category in X. The pie function offsets slices corresponding to true (nonzero) in category order.

labels — Label options

'%.0f%%' (default) | array of text labels | format expression

Label options, specified as an array of text labels or a format expression. Use this argument to display custom text labels with the pie slices, or to display the percentage values that MATLAB^® provides in a specific format.

Note

To specify the label options when X contains categorical values, you must specify the explode argument before the label options.

Display Text Labels

Specify the labels as a cell array of character vectors or as a string array.

When X contains numeric values, the number of elements in labels must equal the number of elements in X.

When X contains categorical values, the number and order of the elements in labels must equal the number and order of the categories in X. To determine the number and order of the categories, use the categories function.

Display Percentages in a Specific Format

Specify a format expression as a character vector or as a string scalar. The format expression begins with a percent symbol (%) followed by a series of identifiers.

All the identifiers are optional except for the conversion character. Specify the identifiers in this order:

1. One or more flags — Options for displaying plus signs, decimal points, and justifying the labels.

   • Plus sign (+) — Display a plus sign next to positive values.

   • Hash symbol (#) — Display the decimal point even when the precision is 0, such as in '50.'.

   • Minus sign (–) — Left justify the labels and pad the ends of the labels with spaces instead of padding them at the beginning.

2. Field width — Minimum number of characters to display in the label. Specify the field width as an integer value. If the number of digits in a label is smaller than the field width, then the label is padded with spaces.

3. Precision — Number of digits to the right of the decimal point. Specify the precision as a decimal point followed by an integer value.

4. Conversion character — Fixed-point or exponential notation. For a list of conversion characters, see the table below. If you specify a conversion character that does not fit the data, MATLAB uses %e instead.

Conversion Character	Description	Example
f	Fixed-point notation. The precision value indicates the number of decimal places.	'%.4f%%' displays the label for a slice that is 6.25% of the pie as 6.2500%.
e	Exponential notation. The precision value indicates the number of decimal places.	'%.4e%%' displays the label for a slice that is 6.25% of the pie as 6.2500e+00%.
g	The more compact version of e or f, with no trailing zeros. The precision value indicates the maximum number of decimal places.	'%.4g%%'displays the label for a slice that is 6.25% of the pie as 6.25%.

In addition to the identifiers listed above, you can also specify literal text at the beginning or end of the format expression. To display a single quotation mark, use ''. To display a percent symbol, use %%. For example, '%.2f%%' displays the labels with two trailing decimal places followed by a percent symbol.

ax — Axes

axes object

Axes object. Use ax to plot the pie chart in a specific axes instead of the current axes (gca).

Output Arguments

p — Patch and Text objects

vector

Patch and Text objects, returned as a vector. For more information, see Patch Properties and Text Properties.

Extended Capabilities

Tall Arrays

Calculate with arrays that have more rows than fit in memory.

This function supports tall arrays with the following limitations:

X must be a tall categorical array.

For more information, see Tall Arrays.

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).

Version History

Introduced before R2006a

R2019b: Pie Charts Display Zero Values

When you call the pie function, and specify data that contains zero values, your pie chart shows the zero values and corresponding labels. If you call pie with an output argument, the output includes objects for each zero value.

In previous releases, pie omitted the zero values from the chart, and it did not return any objects that corresponded to those values. If you do not want to display zero values or return the corresponding objects, then remove the zeros from your data.