Skip to contents

Coerce data.tables

Source: R/check.R
coerce_dt.Rd

Provides consistent coercion of inputs to data.table with error handling, column checking, and optional selection.

Usage

coerce_dt(
  data,
  select = NULL,
  required_cols = select,
  forbidden_cols = NULL,
  group = FALSE,
  dates = FALSE,
  copy = TRUE,
  msg_required = "The following columns are required: ",
  msg_forbidden = "The following columns are forbidden: "
)

Arguments

data

Any of the types supported by data.table::as.data.table()

select

An optional character vector of columns to return; unchecked n.b. it is an error to include ".group"; use group argument for that

required_cols

An optional character vector of required columns

forbidden_cols

An optional character vector of forbidden columns

group

A logical; ensure the presence of a .group column?

dates

A logical; ensure the presence of report_date and reference_date? If TRUE (default), those columns will be coerced with as.IDate.

copy

A logical; if TRUE (default), a new data.table is returned

msg_required

A character string; for required_cols-related error message

msg_forbidden

A character string; for forbidden_cols-related error message

Value

A data.table; the returned object will be a copy, unless copy = FALSE, in which case modifications are made in-place

Details

This function provides a single-point function for getting a "local" version of data provided by the user, in the internally used data.table format. It also enables selectively copying versus not, as well as checking for the presence and/or absence of various columns.

While it is intended to address garbage in from the user, it does not generally attempt to address garbage in from the developer - e.g. if asking for overlapping required and forbidden columns (though that will lead to an always-error condition).

When dates = TRUE, this function ensures that report_date and reference_date columns are coerced to IDate class with integer storage mode. This is necessary because some operations (such as dplyr::filter()) can convert IDate columns to double storage mode whilst preserving the class, which violates data.table's requirements and causes errors in subsequent date arithmetic operations.

See also

Utility functions aggregate_rolling_sum(), coerce_date(), date_to_numeric_modulus(), get_internal_timestep(), is.Date(), stan_fns_as_string()