Document exdf columns by specifying units and categories

Adds new columns to a table-like object, and sets/modifies the units or categories of columns in an exdf object.

Usage

document_variables(x, ...)

  # S3 method for class 'data.frame'
document_variables(x, ...)

  # S3 method for class 'exdf'
document_variables(x, ...)

Arguments

x

A table-like R object such as a data frame or an exdf.

...

Each optional argument should be a character vector with three elements that describe a column, where the first element is the category, the second is the name, and the third is the units. For example, c('GasEx', 'A', 'micromol m^(-2) s^(-1)') specifies that the category and units for the A column are GasEx and micromol m^(-2) s^(-1), respectively. If the column name is not in x, it will be added with all values initialized to NA. Categories and units will be ignored when x is a data frame.

Value

An object based on x with new and/or modified columns.

See also

exdf

Examples

# Create a simple exdf object with two columns (`A` and `B`) and default values
# for its units and categories.
simple_exdf <- exdf(data.frame(A = c(3, 2, 7, 9), B = c(4, 5, 1, 8)))

print(simple_exdf)
#> 
#> Converting an `exdf` object to a `data.frame` before printing
#> 
#>   A [NA] (NA) B [NA] (NA)
#> 1           3           4
#> 2           2           5
#> 3           7           1
#> 4           9           8

# Specify units and categories for the `A` and `B` columns, and add a new `C`
# column.
document_variables(
  simple_exdf,
  c('cat1', 'A', 'm'), # The category of `A` is `cat1` and its units are `m`
  c('cat2', 'B', 's'), # The category of `B` is `cat2` and its units are `s`
  c('cat3', 'C', 'g')  # The category of `C` is `cat3` and its units are `g`
)
#> 
#> Converting an `exdf` object to a `data.frame` before printing
#> 
#>   A [cat1] (m) B [cat2] (s) C [cat3] (g)
#> 1            3            4           NA
#> 2            2            5           NA
#> 3            7            1           NA
#> 4            9            8           NA

# Do the same but for a data frame; in this case columns A and B will not be
# altered, but a new column C will be added (and initialized to NA)
document_variables(
  simple_exdf$main_data,
  c('cat1', 'A', 'm'), # The category of `A` is `cat1` and its units are `m`
  c('cat2', 'B', 's'), # The category of `B` is `cat2` and its units are `s`
  c('cat3', 'C', 'g')  # The category of `C` is `cat3` and its units are `g`
)
#>   A B  C
#> 1 3 4 NA
#> 2 2 5 NA
#> 3 7 1 NA
#> 4 9 8 NA