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Extract actor time range information

Source: R/get_actor_time_info.R
get_actor_time_info.Rd

get_actor_time_info returns a per-actor data.frame of entry and exit times. it dispatches on the first argument:

Usage

get_actor_time_info(x, ...)

# S3 method for class 'netify'
get_actor_time_info(x, ...)

# S3 method for class 'data.frame'
get_actor_time_info(x, actor1, actor2, time, ...)

# Default S3 method
get_actor_time_info(x, actor1, actor2, time, ...)

Arguments

x

a netify object, or a data.frame of dyadic observations.

...

unused; reserved for future methods.

actor1

character string specifying the column name for the first actor in each dyad (data.frame method only).

actor2

character string specifying the column name for the second actor in each dyad (data.frame method only).

time

character string specifying the column name for time periods (data.frame method only).

Value

a data.frame with three columns:

  • actor: character vector of unique actor identifiers.

  • min_time: earliest time period the actor is in the network (entry point).

  • max_time: latest time period the actor is in the network (exit point).

for the netify method, this is a verbatim copy of attr(x, "actor_pds"). for the data.frame method, actors are ordered as they appear in the aggregation, not alphabetically or by time.

Details

  • if x is a netify object, it returns the stored actor_pds attribute directly (one row per actor with min_time / max_time). this is the open-cohort roster the netlet was built with – and the roster every per-period statistic (density, degree, homophily) is computed against.

  • if x is a data.frame of dyadic observations, it computes the entry / exit times from the data. entry is defined as the first time period in which an actor appears in any interaction (as either sender or receiver), and exit as the last time period. use this form to prepare the actor_pds argument to netify().

use cases:

  • on a dyad data.frame: build the actor_pds argument to netify(..., actor_time_uniform = FALSE, actor_pds = ...) for open-cohort panels (panel surveys with attrition, contact-tracing chains, organizational membership over time, etc.).

  • on a netify object: inspect the entry / exit roster the netlet is currently using – useful when debugging density denominators, writing custom exporters, or verifying that an open-cohort netlet has the actor windows you expect.

assumptions (data.frame method):

  • an actor is considered "present" in any time period where they appear in the data, regardless of role (sender/receiver).

  • missing values in time are ignored when calculating min/max.

  • actors must appear in at least one non-missing time period.

Note

the data.frame method assumes that presence in the data indicates network participation. if actors can be temporarily absent from the network while still being considered members, this method will not capture such gaps – supply an explicit actor_pds roster to netify() instead.

Author

shahryar minhas, ha eun choi

cassy dorff, shahryar minhas

Examples

# data.frame input: derive the roster
df <- data.frame(
    i = c("a", "a", "b", "c"),
    j = c("b", "c", "c", "a"),
    t = c(1, 2, 2, 3)
)
get_actor_time_info(df, "i", "j", "t")
#>   actor min_time max_time
#> 1     a        1        3
#> 2     b        1        2
#> 3     c        2        3

# netify input: read back the stored roster
if (FALSE) { # \dontrun{
roster <- data.frame(actor = c("a", "b"), min_time = c(1, 1), max_time = c(3, 4))
net <- netify(df, actor1 = "i", actor2 = "j", time = "t",
              actor_time_uniform = FALSE, actor_pds = roster)
get_actor_time_info(net)
} # }