calc_nbar: This function calculates needed nbar to achieve a given power

Description

This function calculates needed nbar to achieve a given power

Usage

calc_nbar(
  d_m,
  MT = 2.8,
  MDES,
  J = NULL,
  K = NULL,
  Tbar,
  R2.1,
  R2.2 = NULL,
  ICC.2 = NULL,
  omega.2 = NULL,
  R2.3 = NULL,
  ICC.3 = NULL,
  omega.3 = NULL
)

Value

nbar, the number of individuals needed, or NA if not possible given design

Arguments

d_m: a single RCT design (see list/naming convention)
MT: Number of approximate effect-size unit SEs (adjusted for degrees of freedom issues) that the MDES needs to be to achieve desired power. E.g., 2.8 for normal theory.
MDES: scalar; the MDES values for each outcome
J: scalar; the number of schools
K: scalar; the number of level 3 units (districts).
Tbar: scalar; the proportion of samples that are assigned to the treatment.
R2.1: scalar, or vector of length M; percent of variation explained by level 1 covariates for each outcome.
R2.2: scalar, or vector of length M; percent of variation explained by level 2 covariates for each outcome.
ICC.2: scalar, or vector of length M; level 2 (school) intraclass correlation.
omega.2: scalar, or vector of length M; ratio of variance of level 2 average impacts to variance of level 2 random intercepts.
R2.3: scalar, or vector of length M; percent of variation explained by level 3 covariates for each outcome.
ICC.3: scalar, or vector length M; level 3 (district) intraclass correlation.
omega.3: scalar, or vector of length M; ratio of variance of level 3 average impacts to variance of level 3 random intercepts.