Z Package conventions

Function names

Estimator functions

• Input is data set, following the Analysis Data Model (ADaM
• Typically calculate model estimates together with confidence limits
• Output is a model object
• prefix vr_est?

An example is vr_est_KM function that estimates the Kaplan-Meier estimates from a Basic Data Structure (BDS) Time-to-Event (TTE) data set. The output is an survfit object.

plotting functions

• Recognize the model object and proposes a visual pleasing representation
• Layers can be added
• prefix vr_add??
• Plots can be modified using ggplot

An example is vr_plot function that plots the survival function from a survfit object.

Summary functions

• Recognize the input object and summarizes it accordingly
• output is a data frame with the summarized data
• prefix vr_get??

vr_get_xx allows estimation of p-values, calculation of summary statistics and risktables.

=> Creating new objects = vr_get_xxx eg vr_get_tableone, vr_get_risktable, ... get is more general than create eg create_pvalue sounds weird => adding to plot = vr_add_risktable (uses vr_get_risktable), vr_add_annotation (can use any of the vr_get functions) ...