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matlabfunctionoctaveanonymous-functiondimensions

Finding the dimensions of an anonymous function

I have a function in Octave/MATLAB like this:

A = @(x1, x2) [0 1; -1*x1 -0.9*x2^2; x1 3*x2];

And I want to find the dimension of the function. One option to check the amount of columns is:

nargin(A)

Which gives 2 in this case. But how about the rows? I know there are 3 rows. But when I check the dimensions, I'll get:

size(A)
ans = 
   1   1

How to find the amount of rows of the function A?

Solution

  • nargin doesn't check the amount of columns. It returns the number of input arguments of the function instead.

    One straight-forward way would be to input any values and then find the size. i.e.

    >> size(A(0,0))

ans =
     3     2

    If there are a lot of input arguments and you want to automate the process of entering input arguments then:

    >> tmp = num2cell(zeros(nargin(A),1));
>> size(A(tmp{:}))

ans =
     3     2