Calculating the t-test for each row
If I understand you correctly what you want to do is
do t-test (mu=0) for each column of the data.
Treating the data as a data.frame rather than a matrix
you can do something like this and then pick out the
p-values but with 140 t-tests I don't know what you'll
get in terms of anything meaninful.
======================================================
aa <- data.frame(a=rnorm(25, 5, 2), b=rnorm(1:25,
0,1))
mytea <- apply(aa, 2, t.test)
tresults <- lapply(mytea, function(.tres) {
data.frame(t.value=.tres[1],dfs=.tres[2],conf.int1=.tres$conf.int[1],conf.int2=
.tres$conf.int[2],p.value=.tres[3])
})
finalresults <- do.call(rbind, tresults)
=====================================================
(Thanks to Mark Leeds for the lapply approach)
--- Keizer_71 <christophe.lo at gmail.com> wrote:
Hi Everyone, I need some simple help. Here are my codes ##########will give me 10000 probesets#################### data.sub =
data.matrix[order(variableprobe,decreasing=TRUE),][1:10000,]
dim(data.sub) data_output<-write.table(data.sub, file = "c://data_output.csv", sep = ",", col.names = NA) When i export to excel, it shows me this. This is just a short version. There are 1000 rows and 140 columns Sample_1_D Sample_1_C Sample_2_D Sample_2_C 1 2.425509867 11.34031409 11.46868531 11.75741478 Here is my question: How do create a new row and calculate the t-test so that it will give me the p-value Here is what i am looking for. The p-value is not correct but just an example. It needs to calculate the entire each row. There are 10000 rows and 140 columns. thanks Kei Sample_1_D Sample_1_C Sample_2_D Sample_2_C p-value 1 2.425509867 11.34031409 11.46868531 11.75741478 .00341111 I tried something like this. t.test(data.sub,mu=0) I am pretty new to R. I think it is showing me the entire p-value. -- View this message in context:
http://www.nabble.com/Calculating-the-t-test-for-each-row-tp15808716p15808716.html
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