Question

I have a data frame that looks like:

Name       Value1    Value2     Value3
sample1     ttn      mth        lik
sample2     bae      ttn.1      apk
sample3     pas      kasd       mth


dat <- structure(list(Name = c("sample1", "sample2", "sample3"), Value1 = c("ttn", 
"bae", "pas"), Value2 = c("mth", "ttn.1", "kasd"), Value3 = c("lik", 
"apk", "mth")), .Names = c("Name", "Value1", "Value2", "Value3"
), row.names = c(NA, -3L), class = "data.frame")

I would like to rearrange and count frequency so it would look like:

  Value     Source1     Source2
  ttn       sample1
  mth       sample1     sample3
  lik       sample1

How do I do this?

Answer 1

Obviously you will have a ragged array here, so how about this:

sapply(unique(unlist(dat[-1])), function(x) dat[apply(dat[-1],1,function(y) x%in%y),1])
$ttn
[1] "sample1"

$bae
[1] "sample2"

$pas
[1] "sample3"

$mth
[1] "sample1" "sample3"

$ttn.1
[1] "sample2"

$kasd
[1] "sample3"

$lik
[1] "sample1"

$apk
[1] "sample2"