Hi Allin; I wanted to comment you that, in my Gretl 1.6.1, the correlation matrix, cross tabulation, main components, Mahalanobis distance and cross correlogram are always inactive, independently of the type of data set I have (time series, cross section or panel data), is there any problem with it?? Maybe is necessary install any specific program to complete Gretl (like TRAMO or ARIMA X12) Regards Javi --------------------------------- LLama Gratis a cualquier PC del Mundo. Llamadas a fijos y móviles desde 1 céntimo por minuto. http://es.voice.yahoo.com