half_normal {ggDoE}R Documentation

Half-Normal Effects Plots

Description

Half-Normal Effects Plots

Usage

half_normal(
  model,
  method = "Lenth",
  alpha = 0.05,
  label_active = FALSE,
  ref_line = FALSE,
  margin_errors = FALSE,
  point_color = "#21908CFF",
  showplot = TRUE
)

Arguments

model

object of class "lm"

method

Character value. Method to calculate PSE. Default is Lenth. Options include: Zahn, WZahn, Lenth, RMS, Dong, JuanPena, Daniel. See Details.

alpha

specify the significance level to compute margin of errors. Numeric significance level, between 0 and 1. Default is alpha=0.05

label_active

If TRUE, active effects are labeled if the effects cross the computed margin of error (ME). See method argument for more details

ref_line

Dafault is TRUE, if FALSE the abline with slope (1/PSE) is not displayed. Reference line should follow along most points that are not considered outliers.

margin_errors

Default is FALSE, if TRUE the cutoffs for margin of errors (ME) and simultaneous margin of error (SME) are shown

point_color

Change color of points in plot

showplot

Default is TRUE, if FALSE plot will not be shown and a tibble is returned used to create the plot along with the calculated PSE,ME,SME

Details

The method argument is a simple wrapper for the function PSE() from the unrepx R package. For more details you can use ?unrepx::PSE(). The method arguement implements methods of estimating the standard error of effects estimates from unreplicatd designs. The methods include

Value

A tibble with the absolute effects and half-normal quantiles. A ggplot2 version of halfnormal plot for factorial effects is returned

References

Daniel, C (1959) Use of Half-Normal Plots in Interpreting Factorial Two-Level Experiments. Technometrics, 1(4), 311-341

Dong, F (1993) On the Identification of Active Contrasts in Unreplicated Fractional Factorials. Statistica Sinica 3, 209-217

Hamada and Balakrishnan (1998) Analyzing Unreplicated Factorial Experiments: A Review With Some New Proposals. Statistica Sinica 8, 1-41

Juan, J and Pena, D (1992) A Simple Method to Identify Significant Effects in Unreplicated Two-Level Factorial Designs. Communications in Statistics: Theory and Methods 21, 1383-1403

Lenth, R (1989) Quick and Easy Analysis of Unrelicated Factorials Technometrics 31(4), 469-473

Zahn, D (1975) Modifications of and Revised Critical Values for the Half-Normal Plot. Technometrics 17(2), 189-200

Examples

model <- lm(ybar ~ (A+B+C+D)^4,data=adapted_epitaxial)
half_normal(model)
half_normal(model,alpha=0.1,label_active=TRUE,margin_errors=TRUE)
half_normal(model,method='Zahn',alpha=0.1,ref_line=TRUE,
            label_active=TRUE,margin_errors=TRUE)

[Package ggDoE version 0.7.8 Index]