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varargin

Variable-length input argument list

Syntax

Description

example

vararginis an input variable in a function definition statement that enables the function to accept any number of input arguments. Specifyvararginusing lowercase characters, and include it as the last input argument after any explicitly declared inputs.

When the function executes,vararginis a 1-by-Ncell array, whereNis the number of inputs that the function receives after the explicitly declared inputs. However, if the function receives no inputs after the explicitly declared inputs, thenvararginis an empty cell array.

Examples

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Define a function in a file namedacceptVariableNumInputs.mthat accepts a variable number of inputs and displays the values of each input.

typeacceptVariableNumInputs
function acceptVariableNumInputs(varargin) disp("Number of input arguments: " + nargin) celldisp(varargin) end

Call the function with several inputs.

acceptVariableNumInputs(ones(3),'some text',pi)
Number of input arguments: 3 varargin{1} = 1 1 1 1 1 1 1 1 1 varargin{2} = some text varargin{3} = 3.1416

Define a function in a file nameddefinedAndVariableNumInputs.mthat expects two inputs and accepts an additional number of inputs.

typedefinedAndVariableNumInputs
函数definedAndVariableNumInputs (X, Y,变长度输入宗量)disp("Total number of input arguments: " + nargin) formatSpec = "Size of varargin cell array: %dx%d"; str = compose(formatSpec,size(varargin)); disp(str) end

Call the function with several inputs.

definedAndVariableNumInputs(7,pi,rand(4),datetime('now'),'hello')
Total number of input arguments: 5 Size of varargin cell array: 1x3

Call the function with two inputs.vararginis an empty cell array.

definedAndVariableNumInputs(13,42)
Total number of input arguments: 2 Size of varargin cell array: 0x0

Define a function in a file namedvariableNumInputAndOutput.mthat accepts a variable number of inputs and outputs.

typevariableNumInputAndOutput
function varargout = variableNumInputAndOutput(varargin) disp(['Number of provided inputs: ' num2str(length(varargin))]) disp(['Number of requested outputs: ' num2str(nargout)]) for k = 1:nargout varargout{k} = k; end end

Call the function with two inputs and three outputs.

[d,g,p] = variableNumInputAndOutput(6,'Nexus')
Number of provided inputs: 2 Number of requested outputs: 3
d = 1
g = 2
p = 3

Call the function again with no inputs or outputs.

variableNumInputAndOutput
Number of provided inputs: 0 Number of requested outputs: 0

In a file in your working folder, create a wrapper to the plot function that plots a red line. Theredplotfunction accepts a variable-length input argument list and returns a variable-length output argument list. It sets the line color to red, and forwards other input values to theplot函数。这个函数包装器允许您不是sredplotthe same inputs asplotand not specify that the line color is red.

typeredplot.m
function varargout = redplot(varargin) [varargout{1:nargout}] = plot(varargin{:},'Color',[1,0,0]); end

Useredplotto create a line plot.

x = 0:pi/100:2*pi; y = sin(x); redplot(x,y)

Figure contains an axes object. The axes object contains an object of type line.

Callredplotagain, and specify input and output arguments to forward to theplot函数。

h = redplot(x,y,'Marker','o','MarkerEdgeColor','green');

Figure contains an axes object. The axes object contains an object of type line.

Extended Capabilities

Introduced before R2006a