Hello R experts,
I have generated a data set below. I tried to export the object - my.pvalues
(class is "by")
as .txt (or excel file), so the output in matrix form line up nicely in .xls
file. Do I have to convert to some other data formats before using write.table?
I am having difficulty to get this out.
I really appreciate it if anyone here could kindly guide me.
Kevin
##### Data ####
a <- c(rnorm(6,mean=0.5,sd=0.1),rnorm(18,mean=4,sd=1))
b <- factor(rep(LETTERS[1:4], each=3, lenth=24))
grp <- rep(factor(c("WT","TG")), each=12)
d <- as.data.frame(cbind(a,b,grp))
my.pvalues <-by(d,
INDICES=d[,"grp"],
{
FUN=function(x)
pairwise.t.test(x$a,x$b)$p.value
}
)
class(my.pvalues)
[1] "by"
### Results ###
> my.pvalues
d[, "grp"]: 1
1 2 3
2 1 NA NA
3 1 1 NA
4 1 1 1
------------------------------------------------------------
d[, "grp"]: 2
1 2 3
2 0.7629610481 NA NA
3 0.0006906049 0.0006059707 NA
4 0.0164179404 0.0141134949 0.03267941
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