[R] How to generate table output of t-test

Peter Dalgaard P.Dalgaard at biostat.ku.dk
Tue Feb 5 10:59:23 CET 2008


Uwe Ligges wrote:
> Ng Stanley wrote:
>   
>> Hi,
>>
>> Given
>>
>> test <- matrix(c(1, 1,2,2), 2,2)
>> t <- apply(test, 1, t.test)
>>     
>  >
>   
>> How can I obtain a table of p-values, confidence interval etc, instead of
>>     
>
> A quick hack would be:
>
> m <- t(sapply(t, function(x)  c(x[["p.value"]], x[["conf.int"]])))
> colnames(m) <- c("p", "lwr", "upr")
> m
>
>   
Even quicker:

> sapply(t,unlist)
                   [,1]                [,2]
statistic.t        "3"                 "3"
parameter.df       "1"                 "1"
p.value            "0.204832764699133" "0.204832764699133"
conf.int1          "-4.85310236808735" "-4.85310236808735"
conf.int2          "7.85310236808735"  "7.85310236808735"
estimate.mean of x "1.5"               "1.5"
null.value.mean    "0"                 "0"
alternative        "two.sided"         "two.sided"
method             "One Sample t-test" "One Sample t-test"
data.name          "newX[, i]"         "newX[, i]"

Or maybe

> sapply(lapply(t,"[",1:6),unlist)
                         [,1]       [,2]
statistic.t         3.0000000  3.0000000
parameter.df        1.0000000  1.0000000
p.value             0.2048328  0.2048328
conf.int1          -4.8531024 -4.8531024
conf.int2           7.8531024  7.8531024
estimate.mean of x  1.5000000  1.5000000
null.value.mean     0.0000000  0.0000000

-- 
   O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
 (*) \(*) -- University of Copenhagen   Denmark          Ph:  (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)                  FAX: (+45) 35327907



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