describe_ml {quest}

Multilevel Descriptive Statistics

Description

describe_ml decomposes descriptive statistics from multilevel data into within-group and between-group descriptives. The data is first separated out into within-group components via centers_by and between-group components via aggs. Then the psych function describe is applied to both.

Usage

describe_ml(
  data,
  vrb.nm,
  grp.nm,
  na.rm = TRUE,
  interp = FALSE,
  skew = TRUE,
  ranges = TRUE,
  trim = 0.1,
  type = 3,
  quant = NULL,
  IQR = FALSE
)

Arguments

data

data.frame of data.

vrb.nm

character vector of colnames from data specifying the variable columns.

grp.nm

character vector of length 1 of a colname from data specifying the grouping column.

na.rm

logical vector of length 1 specifying whether missing values should be removed before calculating the descriptive statistics. See psych::describe.

interp

logical vector of length 1 specifying whether the median should be standard (FALSE) or interpolated (TRUE).

skew

logical vector of length 1 specifying whether skewness and kurtosis should be calculated (TRUE) or not (FALSE).

ranges

logical vector of length 1 specifying whether the minimum, maximum, and range (i.e., maximum - minimum) should be calculated (TRUE) or not (FALSE). Note, if ranges = FALSE, the trimmed mean and median absolute deviation is also not computed as per the psych::describe function behavior.

trim

numeric vector of length 1 specifying the top and bottom quantiles of data that are to be excluded when calculating the trimmed mean. For example, the default value of 0.1 means that only data within the 10th - 90th quantiles are used for calculating the trimmed mean.

type

numeric vector of length 1 specifying the type of skewness and kurtosis coefficients to compute. See the details of psych::describe. The options are 1, 2, or 3.

quant

numeric vector specifying the quantiles to compute. Foe example, the default value of c(0.25, 0.75) computes the 25th and 75th quantiles of the group number of cases. If quant = NULL, then no quantiles are returned.

IQR

logical vector of length 1 specifying whether to compute the Interquartile Range (TRUE) or not (FALSE), which is simply the 75th quantil - 25th quantile.

Value

list of two elements each containing a data.frame of descriptive statistics, the first for the within-person components ("within") and the second for the between-person components ("between").

See Also

describe

Examples

tmp_nm <- c("outcome","case","session","trt_time")
dat <- as.data.frame(lmeInfo::Bryant2016)[tmp_nm]
stats_by <- psych::statsBy(dat, group = "case") # requires you to include "case" column in dat
describe_ml(data = dat, vrb.nm = c("outcome","session","trt_time"), grp.nm = "case")