smd_calc: SMD Calculation

In TOSTER: Two One-Sided Tests (TOST) Equivalence Testing

SMD Calculation

Description

A function to only calculate standardized mean differences.

Usage

smd_calc(
  x,
  ...,
  paired = FALSE,
  var.equal = FALSE,
  alpha = 0.05,
  bias_correction = TRUE,
  rm_correction = FALSE,
  glass = NULL,
  smd_ci = c("nct", "goulet", "t", "z")
)

## Default S3 method:
smd_calc(
  x,
  y = NULL,
  paired = FALSE,
  var.equal = FALSE,
  alpha = 0.05,
  mu = 0,
  bias_correction = TRUE,
  rm_correction = FALSE,
  glass = NULL,
  smd_ci = c("nct", "goulet", "t", "z"),
  ...
)

## S3 method for class 'formula'
smd_calc(formula, data, subset, na.action, ...)

Arguments

x	a (non-empty) numeric vector of data values.
...	further arguments to be passed to or from methods.
paired	a logical indicating whether you want a paired t-test.
var.equal	a logical variable indicating whether to treat the two variances as being equal. If TRUE then the pooled variance is used to estimate the variance otherwise the Welch (or Satterthwaite) approximation to the degrees of freedom is used.
alpha	alpha level (default = 0.05)
bias_correction	Apply Hedges' correction for bias (default is TRUE).
rm_correction	Repeated measures correction to make standardized mean difference Cohen's d(rm). This only applies to repeated/paired samples. Default is FALSE.
glass	A option to calculate Glass's delta as an alternative to Cohen's d type SMD. Default is NULL to not calculate Glass's delta, "glass1" will use the first group's SD as the denominator whereas "glass2" will use the 2nd group's SD.
smd_ci	Method for calculating SMD confidence intervals. Methods include Goulet, noncentral t (nct), central t (t), and normal method (z).
y	an optional (non-empty) numeric vector of data values.
mu	Null value. Deviating from zero will give the x-y-mu.
formula	a formula of the form lhs ~ rhs where lhs is a numeric variable giving the data values and rhs either 1 for a one-sample or paired test or a factor with two levels giving the corresponding groups. If lhs is of class "Pair" and rhs is 1, a paired test is done.
data	an optional matrix or data frame (or similar: see model.frame) containing the variables in the formula formula. By default the variables are taken from environment(formula).
subset	an optional vector specifying a subset of observations to be used.
na.action	a function which indicates what should happen when the data contain NAs. Defaults to getOption("na.action").

Details

For details on the calculations in this function see vignette("SMD_calcs").

Value

A data frame containing the SMD estimates.

See Also

Other effect sizes: boot_ses_calc(), boot_smd_calc(), ses_calc()

Examples

## Not run: 
smd_calc(formula = extra ~ group,data = sleep, paired = TRUE, smd_ci = "nct")

## End(Not run)

TOSTER documentation built on May 29, 2024, 9:57 a.m.