Skip to contents

Set, activate, deactivate, or clear a per-dataset case-selection expression

jsubset.Rd

jsubset() sets a persistent case-selection expression that is applied automatically by jstats analysis functions when the default data frame (set by juse()) is in use. This is analogous to the SPSS FILTER command.

The expression is stored per dataset, so switching juse() between datasets preserves each dataset's setting independently.

The expression applies whenever the matching dataset is used, regardless of whether it was supplied via juse() or specified explicitly in a function call. To bypass it temporarily without losing it, use jsubset(off) before the analysis and jsubset(on) afterward. This matches the SPSS FILTER / USE ALL convention.

Expressions use standard R logical operators: ==, !=, <, <=, >, >=, & (AND), | (OR), ! (NOT), xor() (XOR), and %in%. Using = for equality or the SPSS-style keywords AND/OR/NOT will produce a helpful error suggesting the correct R syntax.

Usage

jsubset(data, expr)

Arguments

data

Optional data frame. If supplied, the expression is stored on that dataset specifically. If omitted, the dataset set by juse() is used.

expr

A logical expression (e.g. Age < 40 & Gender == 1), or one of the following special values:

off

Deactivate the setting but remember the expression.

on

Reactivate a previously deactivated setting.

NULL

Clear the setting entirely (forget the expression).

If expr and data are both omitted, prints the current jsubset status.

Value

Invisibly returns NULL. Called for its side effect.

See also

jstats for the package overview, workflow conventions, and complete function listing.

Examples

juse(community)
#> Default data frame set to: community
jsubset(Age < 40)                        # Set using juse default
#> jsubset activated for community: Age < 40
jsubset(community, Age < 40)             # Explicit dataset
#> jsubset activated for community: Age < 40
jsubset(Age < 40 & WellbeingScore > 50)  # Compound condition
#> jsubset replaced for community: Age < 40 & WellbeingScore > 50 (was: Age < 40)
jsubset(off)                             # Deactivate
#> jsubset deactivated for community.
jsubset(on)                              # Reactivate
#> jsubset reactivated for community: Age < 40 & WellbeingScore > 50
jsubset()                                # Check status
#> jsubset active for community: Age < 40 & WellbeingScore > 50
jsubset(NULL)                            # Clear entirely
#> jsubset cleared for community (had: Age < 40 & WellbeingScore > 50).
# Not normally needed. You'd clear a default or registration only to
# undo a mistake, or -- as in this example -- to reset state for testing.
juse(NULL)
#> Default data frame cleared.