Hallo I need some help with the output provided by gam.check after a gam fit (using the package mgcv). To give a brief description of my data, I have claims: a vector of values, which include NA's and one large negative value - otherwise all positive (55 values in total that are not NA). origin: a factor with 10 levels j : taking the values 1, 2, ...., 10 I have fitted a gam, with: > library(mgcv) > modelg <- gam(claims ~ origin + s(log(col)), family = quasipoisson(), + subset=!is.na(claims)) (I have obtained a work-around of the quasipoisson family to deal with the negative value.) After this I tried the following: > gam.check(modelg) This gives a plot in the usual way (that looks fine, except for the "outlier" which was a negative value), but returns the following message: fit method: deviance based outer iter. - newton, exact hessian. step failed after 1 iteration. gradient range [9.136047,9.136047] (score 994.1401 & scale 733.0711). Hessian positive definite, eigenvalue range [42.98903,42.98903].
What does this mean? Is there a problem? Any help is much appreciated. Thanks. Jacob L van Wyk Dept of Statistics University of Johannesburg P O Box 524 Auckland Park 2006 South Africa Tel: +27-11-559-3080 Fax: +27-11-559-2832 Cell: +27-82-859-2031 [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.