aggs: Aggregate Data by Group

In quest: Prepare Questionnaire Data for Analysis

Aggregate Data by Group

Description

aggs evaluates a function separately for each group and combines the results back together into a data.frame that is returned. Depending on rep, the results of fun are repeated for each element of data[vrb.nm] in the group (TRUE) or only once for each group (FALSE). Note, aggs evaluates fun separately for each variable vrb.nm within data. If instead, you want to evaluate fun for variables as a set data[vrb.nm], then use agg_dfm.

Usage

aggs(
  data,
  vrb.nm,
  grp.nm,
  rep = TRUE,
  rtn.grp = !rep,
  sep = "_",
  suffix = "_a",
  fun,
  ...
)

Arguments

data	data.frame of data.
vrb.nm	character vector of colnames from data specifying the variables.
grp.nm	character vector of colnames from data specifying the groups.
rep	logical vector of length 1 specifying whether the result of fun should be repeated for every instance of the group in data[vrb.nm] (TRUE) or only once for each group (FALSE).
rtn.grp	logical vector of length 1 specifying whether the group columns (i.e., data[grp.nm]) should be included in the return object as columns. The default is the opposite of rep as traditionally it is most important to return the group columns when rep = FALSE.
sep	character vector of length 1 specifying what string should separate different group values when naming the return object. This argument is only used if grp.nm has length > 1 AND rep = FALSE AND rtn.grp = FALSE.
suffix	character vector of length 1 specifying the string to append to the end of the colnames in the return object.
fun	function to use for aggregation. This function is expected to return an atomic vector of length 1.
...	additional named arguments to fun.

Details

If rep = TRUE, then agg calls ave; if rep = FALSE, then agg calls aggregate.

Value

data.frame of aggregated values. If rep is TRUE, then nrow = nrow(data). If rep = FALSE, then nrow = length(levels(interaction(data[grp.nm]))). The names are specified by paste0(vrb.nm, suffix). If rtn.grp = TRUE, then the group columns are appended to the begining of the data.frame.

See Also

agg, agg_dfm, ave, aggregate,

Examples

aggs(data = airquality, vrb.nm = c("Ozone","Solar.R"), grp.nm = "Month",
   fun = mean, na.rm = TRUE)
aggs(data = airquality, vrb.nm = c("Ozone","Solar.R"), grp.nm = "Month",
   rtn.grp = TRUE, fun = mean, na.rm = TRUE) # include the group columns
aggs(data = airquality, vrb.nm = c("Ozone","Solar.R"), grp.nm = "Month",
   rep = FALSE, fun = mean, na.rm = TRUE) # do NOT repeat aggregated values
aggs(data = mtcars, vrb.nm = c("mpg","cyl","disp"), grp.nm = c("vs","am"),
   rep = FALSE, fun = mean, na.rm = TRUE) # with multiple group columns
aggs(data = mtcars, vrb.nm = c("mpg","cyl","disp"), grp.nm = c("vs","am"),
   rep = FALSE, rtn.grp = FALSE, fun = mean, na.rm = TRUE) # without returning groups

quest documentation built on May 29, 2024, 4:59 a.m.