egor (version 1.24.2)

subset.egor: Filter and Subset Ego-centered Datasets

Description

Functions to index and take subsets of egor() objects: manipulate egos, alters, or alter-alter ties.

Usage

# S3 method for egor
subset(x, subset, ..., unit = attr(x, "active"))
# S3 method for egor
[(x, i, j, unit = attr(x, "active"), ...)

Value

An egor() object.

Arguments

x

an egor() object.

subset

either an expression evaluated on each of the rows of the selected unit (as in the eponymous argument of subset()) or a function whose first argument is a row, specifying which egos, alters, or alter-alter ties to keep. The expressions can access variables in the calling environment; columns of the active unit, columns of other units with which the active unit shares an ego via ego$, alter$, and aatie$ as well as the following "virtual" columns to simplify indexing:

Ego index .egoRow

contains the index (counting from 1) of the row being evaluated. (This can be used to access vector variables in the calling environment.)

Alter index .altRow

contains the index (counting from 1) of the row number in the alter table.

Alter--alter indices .srcRow and .tgtRow

contain the index (counting from 1) of the row of the alter being referenced by .srcID and .tgtID. (This can be used to quickly access the attributes of the alters in question.)

...

extra arguments to subset if subset is a function; otherwise unused.

unit

a selector of the unit of analysis being affected: the egos, the alters or the (alter-alter) ties. Note that only one type of unit can be affected at a time. Defaults to the current active unit selected by activate.egor().

i

numeric or logical vector indexing the appropriate unit.

j

either an integer vector specifying which columns of the filtered structure (ego, alters, or ties) to select, or a logical vector specifying which columns to keep. Note that the special columns .egoID, .altID, .srcID, .tgtID are not indexed by j.

Details

Removing or duplicating an ego will also remove or duplicate their alters and ties.

Examples

# Generate a small sample dataset
(e <- make_egor(5,4))

# First three egos in the dataset
e[1:3,]

# Using an external vector
# (though normally, we would use e[.keep,] here)
.keep <- rep(c(TRUE, FALSE), length.out=nrow(e$ego))
subset(e, .keep)

    # Filter egos
subset(x = egor32, subset = egor32$ego$variables$sex == "m", unit="ego")
subset(x = egor32, sex == "m")

# Filter alters
subset(x = egor32, sex == "m", unit = "alter")

# Filter aaties
subset(x = egor32, weight != 0, unit = "aatie")

# Filter egos by alter variables (keep only egos that have more than 13 alters)
subset(x = egor32, nrow(alter) > 13, unit = "alter")

# Filter alters by ego variables (keep only alters that have egos from Poland)
subset(x = egor32, ego$country == "Poland", unit = "ego")

# Filter edges by alter variables (keep only edges between alters where `sex == "m"`)
subset(x = egor32, all(alter$sex == "m"), unit = "aatie")