Support Variable Number of Inputs
This example shows how to define a function that accepts a variable number of input arguments using
varargin. The varargin argument is a cell array that contains the function inputs, where each
input is in its own cell.
Create a function in a file named plotWithTitle.m that accepts a variable number of paired (x,y)
inputs for the plot function and an optional title. If the function receives an odd number of inputs, it
assumes that the last input is a title.
function plotWithTitle(varargin)
if rem(nargin,2) ~= 0
myTitle = varargin{nargin};
numPlotInputs = nargin - 1;
else
myTitle = 'Default Title';
numPlotInputs = nargin;
end
plot(varargin{1:numPlotInputs})
title(myTitle)
Because varargin is a cell array, you access the contents of each cell using curly braces, {}. The
syntax varargin{1:numPlotInputs} creates a comma-separated list of inputs to the plot
function.
Call plotWithTitle with two sets of (x,y) inputs and a title.
x = [1:.1:10];
y1 = sin(x);
y2 = cos(x);
plotWithTitle(x,y1,x,y2,'Sine and Cosine')
You can use varargin alone in an input argument list, or at the end of the list of inputs, such as
function myfunction(a,b,varargin)
In this case, varargin{1} corresponds to the third input passed to the function, and nargin returns
length(varargin) + 2.
See Also
nargin | varargin
Related Examples
•
“Access Data in Cell Array” on page 12-5
More About
•
“Checking Number of Arguments in Nested Functions” on page 21-8
•
“Comma-Separated Lists” on page 2-79
21 Function Arguments
21-4