plot_traj: Plot observed longitudinal trajectories using facets
In sambrilleman/simjm: Simulate Joint Longitudinal and Survival Data

Description Usage Arguments Value Examples

This is a convenience function that allows the user to easily plot the observed longitudinal biomarker trajectory for each individual. Each individual is shown in a separate facet in the plot. This function can be useful to assess whether the "true" parameter values passed to simjm are generating realistic longitudinal trajectories for the simulated biomarkers.

1 2	plot_traj(yvar = "Yij_1", data, data_filter = NULL, timevar = "tij", idvar = "id")

`yvar`	Name of the variable corresponding to the longitudinal biomarker.
`data`	The data frame with simulated data for the longitudinal submodel. The variable indicating the individual should be called "id", as is the case in the data frames returned by `simjm`.
`data_filter`	Optionally, a condition wrapped in quotes indicating the subset of individuals to include in the plot (for example we could use `data_filter = "id <= 20"` to include plots the first 20 individuals). If `NULL` then a separate facet is included for every individual in `data`.
`timevar`	Name of the variable corresponding to time.
`idvar`	Name of the variable identifying individuals.

A ggplot object that can be further customised using the ggplot2 package.

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  dat <- simjm(n = 20, random_trajectory = "poly", b_sd = c(2,2,2), seed = 123)
  plot_traj("Yij_1", data = dat$Long1)
  plot_traj("Yij_1", data = dat$Long1, data_filter = "id <= 10")