Likelihood ratio test using the anova.yppe() function

library(YPPE)
data(gastric)

ph <- phpe(Surv(time, status)~trt, data = gastric, n_int = 10, init = 0)
po <- pope(Surv(time, status)~trt, data = gastric, n_int = 10, init = 0)
yp <- yppe(Surv(time, status)~trt, data = gastric, n_int = 10, init = 0)
anova(ph, po, yp)
#> 
#> Model 1 ( ph ):  Surv(time, status) ~ trt 
#> Model 2 ( po ):  Surv(time, status) ~ trt 
#> Model 3 ( yp ):  Surv(time, status) ~ trt 
#> --- 
#>             loglik        LR df  Pr(>Chi)    
#> Model 1: -588.4035   11.7338  1 0.0006138 ***
#> Model 2: -586.5475    8.0219  1 0.0046214 ** 
#> Model 3: -582.5366         -  -         -    
#> ---
#> Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
AIC(ph, po, yp)
#>       yp       po       ph 
#> 1189.073 1195.095 1198.807