Register variables as counts for analysis

jcount() tells jstats to treat one or more variables as count variables (non-negative whole-number tallies). A count is numeric-like – it passes wherever a numeric variable does and shows mean/median in jscreen – and additionally carries count semantics: it is the asserted signal behind the count-regression caveat in jlm and the routing target for future count-model functions. Unlike the structural guess, jcount accepts counts of any range, including those outside the automatic small-range detection (e.g. a 0-30 victimization count).

Usage

jcount(data, ..., remove = FALSE, clear.all = FALSE)

Arguments

data: A data frame, or omitted to use the juse default. jcount(NULL) clears the count registrations on the juse default frame (or, with no default set, the only frame that carries them; if several do, it asks rather than wiping all). jcount(data, NULL) clears that one frame's count registrations. Called with no arguments, jcount() lists the session's numeric and count registrations.
...: One or more unquoted variable names to register.
remove: Logical; if TRUE, remove the count registration for the named variables instead of adding it.
clear.all: Logical; if TRUE, clear count registrations on every data frame that carries them.

Value

invisible(NULL). Called for its side effect on the session registration notebook.

Details

A variable carries exactly one registered intent at a time, so registering it as a count clears any prior dummy or numeric registration. Registration changes no data and assigns nothing. It is stored for the session, keyed by the data frame's name; save the data frame in R format (.rds) to keep it across sessions.

Examples

df <- data.frame(arrests = c(0, 1, 2, 0, 3, 1, 0, 12),
                 age      = c(21, 34, 45, 29, 51, 38, 26, 60))
jcount(df, arrests)                 # treat as a count (here 0-12)
#> Count registration set for 'arrests' in df.
#> Note: this registration is stored for this session only.
#> To keep it across sessions, save the data frame in R format (.rds):
#>   jsave(df, "df.rds")
#> 
#> Next session, load that file to restore the registration:
#>   df <- jload("df.rds")
jcount(df, arrests, remove = TRUE)
#> Count registration removed for 'arrests' in df.
jcount()                            # list all registrations
#> No variable registrations in this session.
jcount(df, NULL)                    # clear df's count registrations
#> No count registrations to clear for df.
jcount(clear.all = TRUE)            # clear every frame's count registrations
#> No count registrations to clear.