new_col_meta: Create a new 'col_meta' class object
In a-maldet/readall: Read FWF, DSV, EXCEL And SAS Files

Description Usage Arguments Value meta information See Also

This class holds a set of meta information for a specific column and is usually stored in a file_meta class object, which is usually stored ina file_structure class object.

new_col_meta(
  desc = NULL,
  values = NULL,
  values_desc = NULL,
  valid_start = NULL,
  valid_end = NULL
)

`desc`	An optional string holding a column description.
`values`	An optional vector (character/logical/numeric) usually holding the possible column values (e.g. `c(1, 2)`) or a more abstract text version of the column values (e.g. `c("JJJJMMDD", "99999999", "")`). The argument can be omitted.
`values_desc`	An optional character vector that corresponds to the `values` vector. Each entry of `values_desc` is a more detailed description of the corresponding entry in `values`. If some descriptions are not present, the entries are filled with `NA`. The argument can be omitted. But if `values` and `values_desc` are both present, then they have to be of the same length.
`valid_start`	An optional atomic argument (string or number) holding information about the first data set, in which the current variable is valid (present in the data sets). For example `valid_start = 2017`.
`valid_end`	An optional atomic argument (string or number) holding information about the last data set, in which the current variable is valid (present in the data sets). For example `valid_end = Inf`.

A col_meta class object, holding the meta information for a specific data column.

The col_meta class objects are used in order to store some meta information about single data columns, like additional column desciptions, and column value/level descriptions. In order to store meta information about a set of columns a file_meta class object can be used. This objects store a list of col_meta class objects, where each col_meta class object corresponds to a specific column in a data set. This file_meta class objects are usually stored in file_structure class objects or file_definition class objects. But when calling read_data(), the meta information gets also appended to the resulting data.frame. The meta information stored in a file_structure, a file_definition class object or a read data.frame can be extracted by using the function get_meta(). A col_meta class object holds the following informations:

desc: A string holding the column description.
values: A vector (character/logical/numeric) usually holding the possible column values (e.g. c(1, 2)) or a more abstract text version of the column values (e.g. c("JJJJMMDD", "99999999", "")).
values_desc: A character vector that corresponds to the values vector. Each entry of values_desc is a more detailed description of the corresponding entry in values. If some descriptions are not present, the entries are NA values.