Hi, I am trying to fit t copula to some data, and I am using the following function in the library(QRMlib). Udatac <- apply(datac, 2, edf,adjust=1) tcopulac <- fit.tcopula.rank(Udatac) But the error message come out "Error in fit.tcopula.rank(Udatac) : Non p.s.d. covariance matrix" Could anyone give me some advice? In fact, I am not sure what the "adjust=1" is used for. Many thanks. -- View this message in context: http://www.nabble.com/Fit-t-Copula-tf4152818.html#a11814432 Sent from the R help mailing list archive at Nabble.com.