Re: [Gretl-users] dummify with list and script output window

On Thu, 14 Feb 2013, Pindar wrote: > Hi there, > > I'd like to ask what the interaction operator 'makes'? > > I was working on a function that generates new interaction series for > each step combination of factors. > This is working for a list of factors and generates bivariate > combinations as in A*B > I'm stuck with making it possible to generate A*B*C and so on. > This should be possible with a recursive function! > I think with a new gretl operato '*' the whole procedure would get > much easier to implement. > > I also encountered some bugs (at least on W8): > - having 'opened' a bundle and then using the '= null' command > gretl crashes > - 'smpl full' does 'sometimes' not work in functions - I think if > it's outside a loop. > - 'delete --type==' does not update the symbols window automatically > > Here is the code for the function as well (gonna be implemented in my > new multivariate statistic package). > Perhaps someone has an idea how to solve the sorting issue for more > than A*B. I've documented the new operator (warning: it's "^", not "*") in the CVS version of the manual not very long ago: in the A4 version (http://sourceforge.net/projects/gretl/files/manual/gretl-guide-a4.pdf/dow...) look for pages 91-92. Anyway, the following script should give you a good idea: <hansl> open mroz87.gdt --quiet # the coding below makes it so that # KIDS = 0 -> no kids # KIDS = 1 -> young kids only # KIDS = 2 -> young or older kids series KIDS = (KL6 > 0) + ((KL6 > 0) || (K618 > 0)) list D = CIT KIDS # interaction discrete variables list X = WE WA # variables to "split" list INTER = D ^ X smpl 1 6 print D X INTER -o </hansl> ------------------------------------------------------- Riccardo (Jack) Lucchetti Dipartimento di Scienze Economiche e Sociali (DiSES) Università Politecnica delle Marche (formerly known as Università di Ancona) r.lucchetti(a)univpm.it http://www2.econ.univpm.it/servizi/hpp/lucchetti -------------------------------------------------------