minter

A collection of functions for computing effect sizes of interactions for meta-analysis.

⚠️ This package is under active development and not yet stable. Use with caution.

Installation

You can install the development version of minter from GitHub:

devtools::install_github("fdecunta/minter", force = TRUE)

Example

Calculate the standardized mean difference (SMD) for the interaction between fertilization and CO2 enrichment:

library(minter)


# Create sample data for a 2x2 factorial experiment
# Control: No fertilization, ambient CO2
# Fertilization: Added nutrients
# CO2: Elevated CO2
# Fert_CO2: Both treatments combined

experiment_data <- data.frame(
  Ctrl_mean = 10.2, Ctrl_sd = 2.1, Ctrl_n = 25,  # Control: No treatment
  Fert_mean = 15.7, Fert_sd = 3.2, Fert_n = 25,  # Fertilization only
  CO2_mean = 12.4, CO2_sd = 2.5, CO2_n = 24,    # Elevated CO2 only
  Fert_CO2_mean = 18.9, Fert_CO2_sd = 3.8, Fert_CO2_n = 26  # Both treatments
)

# Calculate SMD for interaction
result <- SMD_inter(
  data = experiment_data,
  col_names = c("SMD", "SMDv"),
  Ctrl_mean = Ctrl_mean,
  Ctrl_sd = Ctrl_sd,
  Ctrl_n = Ctrl_n,
  A_mean = Fert_mean,
  A_sd = Fert_sd,
  A_n = Fert_n,
  B_mean = CO2_mean,
  B_sd = CO2_sd,
  B_n = CO2_n,
  AB_mean = Fert_CO2_mean,
  AB_sd = Fert_CO2_sd,
  AB_n = Fert_CO2_n
)

# Model
library(metafor)
res <- rma.mv(SMD, SMDv, ..., data = experiment_data)