(require "coxreg")
(load "pbc.lsp")
(cox-model :times time :status status :x bili)
(cox-model :times time :status status :x (log bili))

(def mayo-model-formula 
     (as-formula '((term age) (term (log bili)) (term (log protime)) 
                   (term (log alb)) (term edtrt))))

(def mayo-model (cox-model :times time :status status :x mayo-model-formula))

(send mayo-model :plot-delta-betas)

(def typical (list 0 (log 3.5) (log 10) (log 1.75 ) 50)) 
(send mayo-model :plot-survival :xvec typical)