[R] Tukey test for subgroups in a data frame

[arun]

HI,
Try this:
dat1<-read.table(text="
  date name  value
  10/5/2008      L     26
  10/5/2008      L     30
  10/5/2008      L     54
  10/5/2008      L     25
  10/5/2008     M     18
  10/5/2008     M     21
  10/5/2008     M     29
  10/5/2008     M     17
  11/5/2008      L     32
  11/5/2008      L     35
  11/5/2008      L     44
  11/5/2008      L     28
  11/5/2008     M     19
  11/5/2008     M     22
  11/5/2008     M     18
  11/5/2008     M     16
  12/5/2008      L     24
  12/5/2008      L     33
  12/5/2008      L     35
  12/5/2008      L     28
  12/5/2008     M     29
  12/5/2008     M     23
  12/5/2008     M     39
  12/5/2008     M     42
  ",sep="",header=TRUE,stringsAsFactors=FALSE)
 dat1$date<-as.Date(dat1$date,format="%m/%d/%Y")
dat1<-within(dat1,{name<-factor(name)})
res<- lapply(split(dat1,dat1$date),function(x) TukeyHSD(aov(value~name,data=x),"name",ordered=TRUE))
 res
#$`2008-10-05`
 # Tukey multiple comparisons of means
  #  95% family-wise confidence level
   # factor levels have been ordered

#Fit: aov(formula = value ~ name, data = x)

#$name
  #  diff       lwr      upr     p adj
#L-M 12.5 -5.501854 30.50185 0.1402197


#$`2008-11-05`
 # Tukey multiple comparisons of means
  #  95% family-wise confidence level
   # factor levels have been ordered

#Fit: aov(formula = value ~ name, data = x)

#$name
 #   diff     lwr      upr     p adj
#L-M   16 7.13522 24.86478 0.0044882


----------------------------------------
A.K.

----- Original Message -----
From: raz <barvazduck at gmail.com>
To: r-help at r-project.org
Cc: 
Sent: Tuesday, November 13, 2012 11:27 AM
Subject: [R] Tukey test for subgroups in a data frame

Hello,

I have a data frame with the following columns: "date","name","value"
the name is the same for each date
I would like to get TukeyHSD p-value for the differences of "value" between
"name"s in each "date" separately I tried different ANOVA (aov()) but can
only get either tukey by "name" or by "data" but not "name by date"

any suggestions?

Thanks

-- 
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