[Gretl-users] Random draw from a known discrete distribution

Dear all, I am running gretl 2016b on Linux Mint Debian 2. I would like to sample from a known discrete distribution. In particular, given a vector of probabilities p = (p_1,p_2...p_n) (where n can change) with associated natural numbers i = (1,2...n), I would like to make a draw from this distribution. So, my first question is: is there in gretl a built-in function to do this? Of course I can write down some code to accomplish the task, but in R the function "sample" can directly do it. So, in R the simple function: sampleDist = function(p) { sample(seq(1,length(p)),1,replace=T,p) } works as expected, where p is a vector of probabilities. Example: p <- c(0.1, 0.4, 0.2, 0.3, 0.0) sampleDist(p) Therefore, I tried to use R shared libraries and to define functions in R in a foreign block in gretl set R_functions on foreign language=R sampleDist = function(p) { sample(seq(1,length(p)),1,replace=T,p) } end foreign The code is executed in gretl and returns no error, but, when I recall the function, gretl returns an error of "unknown function" ? matrix p = {0.1,0.1,0.5,0.3,0} Generated matrix p ? scalar c = R.sampleDist(p) The symbol 'R.sampleDist' is undefined Error executing script: halting This is an issue that I encounter also when I try to use some simple built-in R function from gretl. For instance, this code (taken from the guide) does not work: ? set R_functions on ? scalar b=R.choose(10,4) The symbol 'R.choose' is undefined Error executing script: halting My R version is 3.1.1 and has been built with the shared library enabled (this is the default option in the Debian package for R) and I checked that gretl has correctly detected the path to R library libR.so in my pc. Is this a problem with the R version and I should upgrade/downgrade R? Any idea or suggestion? Best, Giuseppe -- Giuseppe Vittucci Marzetti Assistant Professor, PhD Department of Sociology and Social Research University of Milano-Bicocca Via Bicocca degli Arcimboldi 8 - Building U7 - Floor III - Room 330 20126 Milan, Italy Phone: +39 0461 882162 Fax: +39 0461 882222 E-mail: giuseppe.vittucci(a)unimib.it