[Gretl-devel] Numerical optimization functions

It just recently struck us that three built-in gretl functions concerned with numerical optimization -- BFGSmax, NRmax and simann -- are anomalous in their treatment of their first argument. In each case the first argument is an initial parameter vector, given in straight "matrix" form, and on exit this matrix holds the optimized vector. This is something that a user-defined function cannot do: modify an argument given in straight, non-pointer form in such a way that the caller ends up with the modified version. While it's not _necessarily_ the case that built-in functions obey the same rules as user-defined ones, we reckon it's very desirable that they do, to avoid potential confusion. So in CVS we have done two things: * Modified these three functions so they accept a matrix-pointer first argument. * Revised the documentation to specify this form of usage. For backward compatibility we have not disabled the old form of usage: calls that give the first argument in straight matrix form will still work. But we recommend that the new form be used in all newly written hansl code. We don't have any specific milestone in mind, but it's possible the old form will be disabled at some future point (with warning, of course). Allin