Here is my real data. Group A is my reference and I want to compare the other groups to group A (dunnett analysis). I want to simulate another 5 random numbers for Group A based on the mean and std for my current Group A. and use the combined the data to do the analysis.
Group Y
A 30.17
B 30.65
A 30.35
C 30.57
D 30.75
A 30.52
E 30.05
F 30.56
G 30.86
A 30.89
H 30.69
I 31.19
J 30.68
K 30.84
A 30.82
B 24.13
C 24.5
D 24.28
Here is my R code:
library(readxl)
library(emmeans)
import the real data
data <- read_excel("Path/Sample.xlsx")
View(data)
A_sd<-sd(data[which(data$Group=="A"),]$Y)
A_mean<-mean(data[which(data$Group=="A"),]$Y)
do 100 times Simulations
sim=100
create vectors to save the anona results.
res = vector("list",sim)
Create data frames for the simulated the data
df_sim<- replicate(n=sim,data.frame(Group = rep('A',5), Y=rep(0,5)),simplify=FALSE)
create data frames for the combined data( real data merged with simulated data)
df_merge<-replicate(n=sim,data.frame(Group=rep(NA,23),Y=rep(0,23)),simplify=FALSE)
for (i in 1:sim)
{
Y<-rnorm(n=5,A_mean,A_sd)
df_sim[[i]]$Y[which(df_sim[[i]]$Group=='A')]<-Y
df_merge[[i]]<-rbind(data,df_sim[[i]])
df_merge[[i]]$Group<-as.factor( df_merge[[i]]$Group)
res[[i]]<- lm(df_merge[[i]]$Y ~ df_merge[[i]]$Group, data = df_merge[[i]])
summary(res[[i]])
#Dunnect analysis comparing other groups to group A
got error df_merge[[i]]Group : operator is invalid for atomic vectors
lssquare[[i]]=emmeans(res[[i]],specs=trt.vs.ctrlk~Group)
}
The code works well until I do the Dunnnet analysis using the emmeans function. I got the error df_merge[[i]]Group : operator is invalid for atomic vectors.
If I change my code to lssquare[[i]]=emmeans(res[[i]],specs=trt.vs.ctrlk~getElement(df_merge[[i]],"Group"),data=df_merge[[i]])
i got the error:Error in [.data.frame(tbl, , vars, drop = FALSE) :
undefined columns selected
Any ideas on how to fix this error? Appreciated for anly help