Example 2.2 from Experimental Design and Analysis for Tree Improvement

Source: R/Exam2.2.R

Exam2.2 is used to compare two seed lots by using ANOVA under RCB Design.

References

  1. E.R. Williams, C.E. Harwood and A.C. Matheson (2023). Experimental Design and Analysis for Tree Improvement. CSIRO Publishing (https://www.publish.csiro.au/book/3145/).

See also

DataExam2.2

Author

  1. Muhammad Yaseen (myaseen208@gmail.com)

  2. Sami Ullah (samiullahuos@gmail.com)

Examples

library(car)
library(dae)
library(dplyr)
library(emmeans)
library(ggplot2)
library(lmerTest)
library(magrittr)
library(predictmeans)
library(supernova)

data(DataExam2.2)

# Pg. 24
fmtab2.5 <- lm(formula  = dbh ~ Blk + SeedLot, data = DataExam2.2)

# Pg. 26
anova(fmtab2.5)
#> Analysis of Variance Table
#> 
#> Response: dbh
#>           Df Sum Sq Mean Sq F value  Pr(>F)  
#> Blk        7 48.867  6.9810  3.8959 0.04671 *
#> SeedLot    1 14.270 14.2695  7.9635 0.02570 *
#> Residuals  7 12.543  1.7919                  
#> ---
#> Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
supernova(fmtab2.5, type = 1)
#>  Analysis of Variance Table (Type I SS)
#>  Model: dbh ~ Blk + SeedLot
#> 
#>                                SS df     MS     F   PRE     p
#>  ------- --------------- | ------ -- ------ ----- ----- -----
#>    Model (error reduced) | 63.136  8  7.892 4.404 .8343 .0330
#>      Blk                 | 48.867  7  6.981 3.896 .7957 .0467
#>  SeedLot                 | 14.270  1 14.270 7.964 .5322 .0257
#>    Error (from model)    | 12.543  7  1.792                  
#>  ------- --------------- | ------ -- ------ ----- ----- -----
#>    Total (empty model)   | 75.679 15  5.045                  

# Pg. 26
emmeans(object = fmtab2.5, specs = ~ SeedLot)
#>  SeedLot emmean    SE df lower.CL upper.CL
#>  SO        30.6 0.473  7     29.5     31.7
#>  P         28.7 0.473  7     27.6     29.8
#> 
#> Results are averaged over the levels of: Blk 
#> Confidence level used: 0.95 
emmip(object = fmtab2.5, formula = ~ SeedLot) +
  theme_classic()