在MATLAB函数参数中使用'full'

Question

In some libraries, eg the one below from CVX, I notice the argument full . I can't seem to find any documentation that explains what this is and why it's there. Can anyone explain?

EDIT: As suggested, here is a link to the function . Please note that this is the entire function.

function y = cvx_isaffine( x, full ) 
narginchk(1,2);
if nargin == 1,
    y = true;
else
    y = true( size( x ) );
end

Answer 1

In this function, the test if nargin == 1 checks to see if the second input argument, full is given. If it is, the output is a logical array of same size as x . If it is not, then the output is a scalar logical array.

That is,

M = randn(10,3);
cvx_isaffine(M)

returns true , whereas

cvx_isaffine(M,1)

returns a 10x3 array with all elements are true .

You can fill in whatever you want for this second argument, as its value is not used anywhere. Just the presence of the 2nd argument is a flag for a change in behavior.

The function seems to not be documented because it is meant for internal use, and not for use by the end-user.