Surv 	 	 Package a survival variable 
clogit		 Conditional logistic regression
cluster 	 Identify clusters. 
cox.zph 	 Test the proportional hazards assumption of a Cox regression. 
coxph 	 	 Proportional Hazards Regression 
coxph.detail 	 Details of a cox model fit 
coxph.object 	 Proportional Hazards Regression Object 
coxph.rvar 	 Robust variance for a Cox model 
frailty		 Frailty models by penalised likelihood
is.ratetable 	 Verify that an object is of class ratetable. 
lines.survfit 	 Add lines to a survival plot 
plot.cox.zph 	 Graphical test of proportional hazards (requires splines)
plot.survfit 	 Plot method for survfit. 
print.survfit 	 Short summary of a survival curve 
pspline		 Penalised (smoothing) splines
pyears 	 	 Person Years 
residuals.coxph  Calculate residuals for a coxph fit. 
residuals.survreg Compute Residuals for survreg Objects
ridge		 ridge regression 
strata 	 	 Identify strata variables. 
summary.survfit  Print a Survival Curve 
survdiff 	 Test Survival Curve Differences 
survexp 	 Compute Expected Survival 
survexp.fit 	 Compute expected survival 
survexp.usr      Mortality tables for US and some states (requires date)
survfit 	 Compute a survival Curve for Censored Data 
survfit.object 	 Survival Curve Object 
survobrien 	 O'Brien's test for association of a variable with survival 
survreg 	 Regression for a parametric survival model 
survreg.object 	 Parametric Survival Model Object 
survSplit	 Split data for creating time-dependent covariates.
anova.survreg    ANOVA tables for survreg objects
untangle.specials  Help process the 'specials' argument of the terms function. 

-------- date functions --------------
as.date          Coerce Data to Dates
date.ddmmmyy     Format a Julian date
date.mdy         Convert from Julian Dates to Month, Day, and
                         Year
date.mmddyy      Format a Julian date
date.mmddyyyy    Format a Julian date
date.object      Date Objects
mdy.date         Convert to Julian Dates
