[Gretl-users] Issue with dummify command and a head scratcher

Good afternoon. 1) I have a series X characterized as discrete, with 9 unique values, one of them negative the other positive. When I execute dummify X I get all 9 dummies that the command should produce. I found out that I can also execute list dumXlist = dummify(X) ...but in which case the command does not produce the dummy_1, related to the negative value, and so the dumXlist contains only 8 dummies. Note: the dummies that are produced are labelled correctly, namely their names start from DX_2, DX_3 etc. So Gretl tells me "I know there is one more dummy in there, but I won't create it"... is this a bug? I want to use the command "list" because the whole thing will be inside a loop. 2) I was unable to determine the combination of Gretl commands that will give me the following: Let X be a series, X(i), i=1,...,n. I want to create the following series Y(i) = "the immediately smaller value than X(i) in the X series". (If the Y series is created using a loop, I guess I can deal with what happens when X(i) is the minimum value in the series by an "if" command) E.g. if the X series has unique values {-3,  -1,     5,   17}, then X(i) = 5 => Y(i) = -1, X(j) = -1 => Y(j) = -3,   etc. I would much appreciate any ideas. -- Alecos Papadopoulos PhD Athens University of Economics and Business web: alecospapadopoulos.wordpress.com/