On Fri, 23 Mar 2012, clarodina clarodina wrote: corr Output: scalar Arguments: y1 (series or vector) y2 (series or vector) Computes the correlation coefficient between y1 and y2. The arguments should be either two series, or two vectors of the same length. See also cov, mcov, mcorr. ... mcorr Output: matrix Argument: X (matrix) Computes a correlation matrix treating each column of X as a variable. See also corr, cov, mcov. Gretl comes with TWO manuals: one is the User's Guide. The other one is the Command Reference, which also contains documentation on the functions. The information contained in the Command reference can also be found under the Help menu, under "Command reference" and "Function Reference", respectively. Riccardo (Jack) Lucchetti Dipartimento di Economia Università Politecnica delle Marche (formerly known as Università di Ancona) r.lucchetti(a)univpm.it http://www2.econ.univpm.it/servizi/hpp/lucchetti