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. Registrations are stored under the data frame's name, so it is given as a name (or as a place such as lst$d); an expression that builds one is refused, with the two lines that name it first. The NULL and remove = TRUE forms work on a name whose data frame has since been removed.
...: One or more unquoted variable names to register. The registration applies to numeric variables and to haven-labelled variables that hold numbers. Any other type is refused, and none of the call's variables is then registered: convert a factor or a text variable to numbers first with jencode.
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:
#>   jload("df.rds")
jcount(data = df, arrests)          # the data frame by name
#> 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:
#>   jload("df.rds")
juse(df); jcount(arrests); juse(NULL)  # or the juse() default
#> Default data frame set to: df
#> Using default data frame: df
#> 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:
#>   jload("df.rds")
#> Default data frame cleared.
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.