R-based workflow for the AgeingError package

Ian Taylor

2026-06-16

Note: for a general introduction to the AgeingError package and its model structure, see the Getting Started vignette.

Helper functions in AgeingError

The AgeingError package provides a set of helper functions to create input files and run the ageing error model from R.

The main helpers are:

• write_data_file(): write an input data file from an R data frame or tibble.
• write_specs_file(): write an input specifications file from user inputs for bias and sigma options.
• write_files(): convenience wrapper that calls write_data_file() and write_specs_file() together.
• run(): load the generated files (via load_data() and load_specs()) and run the TMB estimation.

Flowchart of workflow with separate calls to write_data_file() and write_specs_file():

Flowchart of workflow where writing the files are combined in a single call to write_files():

Writing the data file

write_data_file() creates the data file. The main required input is an R data frame or tibble with columns for each reader and rows for each age reading combination (including a count column) or each individual fish (with repeats), in which case the tally_repeats() function will be called to add the count column.

Defaults will be calculated for minage, maxage, refage, minusage, and plusage if not provided, but these can be overridden by the user.

library(AgeingError)

data_test <- data.frame(
  reader1 = c(7, 10, 7, 6, 6, 10, 7, 9, 8, 10, 10, 5, 6, 7, 9, 7, 7, 5, 8, 5),
  reader2 = c(8, 10, 7, 6, 6, 10, 7, 9, 8, 10, 10, 5, 6, 7, 9, 7, 7, NA, NA, NA),
  reader3 = c(7, 10, 7, 6, 6, 8, 7, 9, 8, 10, 10, 5, 6, 7, NA, NA, NA, 5, 8, 5)
)

write_data_file(
  dat = data_test,
  dir = tempdir(),
  file_name = "age_error.dat"
)

Writing the specifications file

write_specs_file() creates the specifications file. This file defines bias options and sigma options for each reader. See the Getting Started vignette vignette for details on the options. The options are provided as a vector of length equal to the number of readers. When called directly, this function also requires the number of readers (nreaders) to be specified. If called via write_files(), the number of readers will be inferred from the data file.

write_specs_file(
  dir = tempdir(),
  file_name = "age_error.spc",
  nreaders = 4,
  biasopt = c(0, 0, 0, 0),
  sigopt = c(1, -1, 7, 8)
)

The options that use cubic splines for uncertainty (sigopt = 5 and sigopt = 6), the knotages argument must be a list of numeric knot locations with one element per reader. Use NA for readers that do not need knots.

write_specs_file(
  dir = tempdir(),
  file_name = "age_error.spc",
  nreaders = 4,
  sigopt = c(5, -1, 7, 8),
  knotages = list(c(0, 3, 5, 7, 9), NA, NA, NA)
)

Note that the R helper functions do not provide the user with control over the parameter lines (low, high, or initial values). If the defaults need to be changed, they can be modified by editing the text files directly.

Convenience wrapper: write_files()

write_files() is a convenience helper that writes both the data and specs files in a single call.

write_files(
  dat = data_test,
  dir = tempdir(),
  file_dat = "age_error.dat",
  file_specs = "age_error.spc",
  biasopt = c(0, 0, 0),
  sigopt = c(1, -1, 2)
)

This is equivalent to running write_data_file() and write_specs_file() separately and is the recommended workflow for most users.

Running the model

run() wraps the full process of loading the generated files and executing AgeingError.

write_files(dat = data_test, dir = tempdir())
out <- run(dir = tempdir())

# model results
out$model$par
out$output$ModelSelection

Note that run() calls load_data() and load_specs() internally, then passes the resulting objects to DoApplyAgeError() and ProcessResults(). These functions could be called directly as needed.