New covariate

Describe data for a covariate, either fixed or time-variant

Usage

new_covariate(
  value = NULL,
  times = NULL,
  implementation = c("interpolate", "locf"),
  unit = NULL,
  interpolation_join_limit = 1,
  remove_negative_times = TRUE,
  round_times = NULL,
  comments = NULL,
  verbose = TRUE
)

Arguments

value

a numeric vector

times

NULL for time-invariant covariate or a numeric vector specifying the update times for the covariate

implementation

for time-varying covariates either 'locf' (last observation carried forward) or 'interpolate' (default). Non-numeric covariate values are assumed to be locf.

unit

specify covariate unit (optional, for documentation purposes only)

interpolation_join_limit

for interpolate option, if covariate timepoints are spaced too close together, the ODE solver sometimes chokes. This argument sets a lower limit on the space between timepoints. It will create average values on joint timepoints instead. If undesired set to NULL or 0.

remove_negative_times

should times before zero be discarded (with value at time zero determined based on implementation argument), TRUE or FALSE.

round_times

round times to specified number of digits. If NULL, will not round.

comments

NULL, or vector of length equal to value specifying comments to each observation (optional, for documentation only)

verbose

verbosity

Value

Object of class "covariate"