Why there is no p-value from likelihood ratio test using anova in GAM model fitting?
willow1980 wrote:
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
We can't make further suggestions until you (1) provide the output of sessionInfo() ; (2) provide a reproducible example. The following example works for me: library(mgcv) example(anova.gam) b1 <- gam(y~x0+s(x1)+s(x2),family=quasipoisson,data=dat) b2 <- gam(y~x0+s(x1),family=quasipoisson,data=dat) anova.gam(b1,b2,test="F") Analysis of Deviance Table Model 1: y ~ x0 + s(x1) + s(x2) Model 2: y ~ x0 + s(x1) Resid. Df Resid. Dev Df Deviance F Pr(>F) 1 187.9672 83.684 2 194.2014 226.042 -6.2342 -142.358 51.291 < 2.2e-16 *** Unless you can provide us with an example that _will not work_ when we run it, it will be hard for us to help you. Ben Bolker
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