How do I create a data table in code in R

I have a data table as a CSV file that I use to create metrics for a dashboard. The data table includes Metric IDs and associates these with field names. This table--this definition of metrics--is largely static, and I'd like to include it within R code rather than, for example, importing a CSV file containing these headings.

The table looks something like this:

Metric_ID	Metric_Name	Numerator	Denominator
AB0001	Number_of_Customers	No_of_Customers
AB0002	Percent_New_Customers	No_of_New_Customers	No_of_Customers

This has about 40 rows of data, and I'd like to set this table up in code so that it is created at the time the R query is run. I'll then use it to associate metric IDs with measures I retrive through SQL queries. Sometimes this table may change -- for example, new metrics might be added or existing metrics modified. This would need some modificatoin in the code to incorporate these metrics.

The closet way I could find was to create a data table, along the lines described in the query below.

dt<-data.table(x=c(1,2,3),y=c(2,3,4),z=c(3,4,5))
dt

   x y z
1: 1 2 3
2: 2 3 4
3: 3 4 5

cbind with data table and data frame

This works for a table with a few rows or columns, but will be unwieldy for tables with 40+ rows. For example, if I wanted to modify a metric 20 rows down, I'd have to go 20 rows down in each column, and then test the table to ensure I switched the metric at the right place in each column -- especially where some metrics have empty cells. for example, I may correct the metric ID in row 20, but accidentally put the definition (a separate column) in row 19.

Is there a more straightforward way of, in essence, creating a table in code?

(I appreciate the most straightforward way would be to keep a CSV file accessible and use read_csv to import it into R. However, this doesn't work so well if colleagues are running this query on their machine and have a different file path to the CSV -- it also raises the risk of them running the query with an out-of-date metrics table, as they may not have the latest version in their files).

Thanks in advance for any guidance you might have!

Tony

Solution

Here are two options (examples taken from respective help pages):

data.table::fread()

fread("A,B
1,2
3,4
")
#>        A     B
#>    <int> <int>
#> 1:     1     2
#> 2:     3     4

https://rdatatable.gitlab.io/data.table/reference/fread.html

tibble::tribble()

tribble(
  ~colA, ~colB,
  "a",   1,
  "b",   2,
  "c",   3
)
#> # A tibble: 3 × 2
#>   colA   colB
#>   <chr> <dbl>
#> 1 a         1
#> 2 b         2
#> 3 c         3

https://tibble.tidyverse.org/reference/tribble.html

Other options:

If you already have the data.frame from somewhere, you can also use dput() to get a structure() code you can paste into the files you are distributing.
use the reprex package https://reprex.tidyverse.org/