Thank you Dr. David. I try to summarize it. Assumes x and z are two covariates: x = dummy variable (1 or 0) z = factors (people name)
x*z = x + z + x*z therefore this is not a 2nd-order interactions, it should be (for an exponential survival regression):- h(t|(X=x,Z=z)) = exp(Beta0 + XZBeta1) #--------------------------------------------------- I believe there is no 2nd-order interactions survival regression as I searched over www.rseek.org. While I tried to read through the codes of survreg(), I stuck (cannot understand) at survreg6.c survreg6.c apply C Language which involves Cholesky decomposition multi-matrix (first-order interactions) calculation. 1) chinv2.c 2) cholesky3.c 3) chsolve2.c (only solve the equations of first-order interactions) If someone gives some idea or suggestion on these? Thank you. Best, Ryusuke -- View this message in context: http://r.789695.n4.nabble.com/Second-order-effect-in-Parametric-Survival-Analysis-tp4034318p4036005.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.
