[Gretl-devel] Re: Default col argument for matrix creation functions

On Sun, 7 Jul 2019, Sven Schreiber wrote: > Well except for F_IMAT where the second arg isn't skipped but is > actually NULL, right? Actually, you got me thinking about the possibility of having a second argiment to I() (aka F_IMAT); in many cases, you want to construct a matrix that is an identity matrix "plus some zeros"; without loss of backward compatibility, we may introduce an optional 2nd argument to I() such that I(r,c) returns * I(r) ~ zeros(r, c-r) if c > r, * I(c) | zeros(r-c, c) if r < c and obviously I(r) if r == c; in this way, building (say) a companion matrix would be really easy; for example, comp = A | I(cols(A) - rows(A), cols(A)) Besides, I believe this is what Matlab does, so this would also be nice to have when porting scripts from the Octave/Matlab galaxy. Do you guys like the idea?