Hi, Dieter, I did add (test="F") in my script, but it does not matter. The following is my whole script.
################################################################# modelsurs_fer13<-gam(sum_surv15~s(FLBS)+SES+s(byear)+s(FLBS,byear),family=quasipoisson) modelsurs_fer14<-gam(sum_surv15~s(FLBS)+s(byear)+s(FLBS,byear),family=quasipoisson) anova.gam(modelsurs_fer14,modelsurs_fer13,test="F") ################################################################# Would you please make further suggestions? Thank you in advance! Jianghua Dieter Menne wrote: > > willow1980 <jianghua.liu <at> shef.ac.uk> writes: > >> However, when I run LRT to compare >> them, the test did not return F value and p-value for me. What's the >> reason? >> >> #################################################### >> Analysis of Deviance Table >> >> Model 1: sum_surv15 ~ s(FLBS) + s(byear) + s(FLBS, byear) >> Model 2: sum_surv15 ~ s(FLBS) + SES + s(byear) + s(FLBS, byear) >> Resid. Df Resid. Dev Df Deviance F Pr(>F) >> 1 1202.21094 601.27 >> 2 1201.43848 601.29 0.77246 -0.02 >> #################################################### > > -- Provide at least the command line you used > -- Wild guess: Try to add test="F" (which is indicated in the docs) > > Dieter > > ______________________________________________ > 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. > > -- View this message in context: http://www.nabble.com/Why-there-is-no-p-value-from-likelihood-ratio-test-using-anova-in-GAM-model-fitting--tp23275224p23277535.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.