Add a number-at-risk panel

Adds the at-risk table layer to a TTE plot: a separate panel stacked below the curve, showing the number of subjects still at risk at a grid of time points, computed from the fit already stored internally within the plot object.

Usage

er_tte_add_risktable(object, style = NULL, times = NULL, n_times = 6, ...)

Arguments

object: Partially constructed plot (has S3 class er_tte).
style: Style used to generate the at-risk table in the plot. Can either be a string corresponding to one of the registered style labels (e.g., "text", the default), or a builder function used to compute the relevant plot object (see "Styles" below).
times: Numeric vector of time points at which to report the number at risk, or NULL (the default) to use n_times evenly spaced breaks across the time range.
n_times: Number of evenly spaced breaks to use when times is NULL. Must be a single whole number of at least 2. Ignored when times is supplied. Defaults to 6.
...: Additional named arguments forwarded to the style builder function when the plot is built.

Value

The input object, with the risktable layer added.

Details

The time breaks used for the number-at-risk grid also become the x-axis tick marks on the primary plot, so the two panels' collected x-axis lines up exactly (see er_tte_build()).

Styles

The following pre-defined styles are available for this layer. Please see the documentation for the corresponding builder function to see what customisation options are available:

Label	Builder	Description
`"text"`	`er_style_tte_risktable_text()`	Number-at-risk counts as a text grid, one row per stratum (the only built-in, and the default).

See er_style_tte() for details on how style builder functions are defined for the TTE mini-grammar, should a custom style be required.

Examples

library(survival)
lung |>
  er_tte(time, status == 2) |>
  er_tte_add_curve() |>
  er_tte_add_risktable() |>
  plot()