MATLAB: Function with variable number of input arguments

functionsinput

Hey everyone,

I created a function called matrixmultiply, and I'm trying to define it for 2, 3, and 4 input arguments. How do I do this in one single script? I've heard "varargin" and "nargin" variables could work, but I don't know how to use those.

(I've defined it separately for 4 arguments already.)

Thanks!

Best Answer

In your case you can just use nargin to know the number of inputs. Look at this example

function y=fcn10(a,b,c,d)
if nargin==2
    y=a+b
elseif nargin==3
    y=a*b*c
elseif nargin==4
    y=(a+b)*(c+d)
end

Related Solutions

MATLAB: Hi, what should I do to get the ‘Not enough input arguments’-error,

Hi Rebecca,

your problem seems to be closely related to the question of strict data typing for function arguments in Matlab. As far as I know, you cannot do it automatically in Matlab. Matlab functions usually start with checking the number and data type of the input arguments manually, see e.g. gaussmf from the statistics toolbox with 7 lines of checking input arguments and 2 lines of actual code (R2014b).

There are several ways of checking the input arguments:

Using nargin (or narginchk), is* and error. Check the Fundamental MATLAB Classes to get a feeling of the checks you need to perform.
Using the validateattributes function.
Using the inputParser class.
Using try catch
Compile it as a mex-function. You will need to specify the datatypes before compiling.

MATLAB: Enable/disable parameter in embedded matlab function

function y=fcn(a,b,c,d)
if d==1
 y=a
elseif d==2
 y=a+b
elseif d==3
 y=a+b+c
end

%or

function y=fcn(a,b,c,d)
v=[a b c];
y=sum(v(1:d))

Best Answer

Related Solutions

MATLAB: Hi, what should I do to get the ‘Not enough input arguments’-error,

MATLAB: Enable/disable parameter in embedded matlab function

Related Question