Quade: Quade Method for Nonparametric ANCOVA

In npANCOVA: Nonparametric ANCOVA Methods

Quade Method for Nonparametric ANCOVA

Description

Performs Quade's ANCOVA using ranked variables and analysis of residuals. The method fits a linear model of the ranked response on the ranked covariates, and then performs an ANOVA on the residuals of that model.

Usage

Quade(data, formula)

Arguments

data	A data frame containing the variables specified in the formula.
formula	An object of class "formula": a symbolic description of the model to be fitted. The structure should be 'response ~ covariate1 + ... + group'.

Value

A list containing the following components:

regression_equation

Summary of the linear model regressing the ranked response on the ranked covariates.

anova_summary

The summary of the ANOVA model performed on the residuals.

group_means

A data frame of the mean of residuals for each group.

group_sds

A data frame of the standard deviation of residuals for each group.

regression_equation_residuals

The summary of the model fitting residuals on the group.

data

The original data frame augmented with ranked variables and residuals.

References

Quade DJJotASA. Rank analysis of covariance. 1967;62(320):1187-200.

Olejnik SF, Algina JJER. A review of nonparametric alternatives to analysis of covariance. 1985;9(1):51-83.

Examples

# 1. Create a sample data frame
data <- data.frame(
  group = c(1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3),
  response = c(16, 60, 82, 126, 137, 44, 67, 87, 100, 142, 17, 28, 105, 149, 160),
  covariate1 = c(26, 10, 42, 49, 55, 21, 28, 5, 12, 58, 1, 19, 41, 48, 35),
  covariate2 = c(12, 21, 24, 29, 34, 17, 2, 40, 38, 36, 8, 1, 9, 28, 16)
)

# 2. Run the Quade method
results <- Quade(
  formula = response ~ covariate1 + covariate2 + group,
  data = data
)

# 3. View the results
print(results)
print(results$anova_summary)

npANCOVA documentation built on Nov. 9, 2025, 5:06 p.m.