[R] Calculating the t-test for each row

[Henrique Dallazuanna]

You can try this:

cbind(data.sub, p.value=apply(data.sub, 1, function(x)t.test(x)$p.value))

On 03/03/2008, 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.
>
>
>
>  --
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>
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-- 
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O