daewr (version 1.1-8)

Tukey1df: This function performs Tukey's single degree of freedom test for interaction in an unreplicated two-factor design

Description

This function performs Tukey's single degree of freedom test for interaction in an unreplicated two-factor design

Usage

Tukey1df(data)

Arguments

data

input - this is a data frame with three variables, the first variable is a numeric response and next two variables are factors. There should be \(ab\) lines in the data frame where \(a\) is the number of levels of the first factor, and \(b\) is the number of levels of the second factor.

Examples

# NOT RUN {
library(daewr)
data(virus)
Tukey1df(virus)

## The function is currently defined as
function (data) 
{
    y <- data[, 1]
    Afactor <- data[, 2]
    Bfactor <- data[, 3]
    tst1 <- is.factor(Afactor)
    tst2 <- is.factor(Bfactor)
    tst3 <- is.numeric(y)
    if (tst1 & tst2 & tst3) {
        a <- nlevels(Afactor)
        b <- nlevels(Bfactor)
    }
    else {
        stop("The first column of the data frame is the numeric response, 
		the 2nd and 3rd columns should be coded as factors")
    }
    tst4 <- max(a, b) > 2
    tst5 <- length(y) == a * b
    if (tst4 & tst5) {
        ybb <- with(data, tapply(y, Bfactor, mean))
        yba <- with(data, tapply(y, Afactor, mean))
        sbb <- with(data, tapply(y, Bfactor, sum))
        sba <- with(data, tapply(y, Afactor, sum))
        ybardd <- mean(y)
        CT <- (sum(y)^2)/(a * b)
        ssA <- sum(sba^2/b) - CT
        ssB <- sum(sbb^2/a) - CT
        ssE <- sum(y^2) - CT - ssA - ssB
        ybdj <- rep(ybb, 6)
        prody <- y * ybdj
        sumprod <- tapply(prody, Afactor, sum)
        leftsum <- sum(sumprod * yba)
        ssAB <- (a * b * (leftsum - (ssA + ssB + a * b * ybardd^2) * 
            ybardd)^2/(ssA * ssB))
        ssR <- ssE - ssAB
        F <- ssAB/(ssR/((a - 1) * (b - 1) - 1))
        Pval <- 1 - pf(F, 1, ((a - 1) * (b - 1) - 1))
        cat("Source           df     SS        MS        F     Pr>F", 
            "\n")
        cat("A            ", paste(format(a - 1, width = 6), 
            " ", format(round(ssA, 4), justify = "right"), "  ", 
            format(round(ssA/(a - 1), 4), justify = "right"), 
            "\n"), sep = "")
        cat("B            ", paste(format(b - 1, width = 6), 
            " ", format(round(ssB, 4), justify = "right"), "  ", 
            format(round(ssB/(b - 1), 4), justify = "right"), 
            "\n"), sep = "")
        cat("Error        ", paste(format((b - 1) * (a - 1), 
            width = 6), " ", format(round(ssE, 4), justify = "right"), 
            "  ", format(round(ssE/(a - 1) * (b - 1), 4), justify = "right"), 
            "\n"), sep = "")
        cat("NonAdditivity", paste(format(1, width = 6), " ", 
            format(round(ssAB, 4), justify = "right"), "  ", 
            format(round(ssAB, 4), justify = "right"), "  ", 
            format(round(F, 2), justify = "right"), "  ", format(round(Pval, 
                4), justify = "right"), "\n"), sep = "")
        cat("Residual     ", paste(format((b - 1) * (a - 1) - 
            1, width = 6), " ", format(round(ssR, 4), justify = "right"), 
            "  ", format(round(ssR/((a - 1) * (b - 1) - 1), 4), 
                justify = "right"), "\n"), sep = "")
    }
    else {
        stop("This function only works for unreplicated 2-factor 
		factorials with >2 levels for one of the factors")
    }
  }
# }