Hi,
I know this is something that has been discuss many time earlier in this
list but I haven't been able to find out any answer from the archives. So
maybe someone could give me a hand with my prolem.
I have a dataframe, with repeated observations ,from 2 to 5 observations,
for each subject: Number of observation vary depending of the subject.
What I am trying to do is to get the cumumative sum of the observations for
each subject.
I managed to get the result I want through the "tapply" function. But it
sorts out a list that I would like to transforme as a dataframe with one
colonne for ID and the second
for the cumulative sum.
tapply(temp$tex,list(temp$id),cumsum) # temp$tex is 1 at every column which
gave me the following output.
$"23236":
[1] 1 2
$"23467":
[1] 1 2 3 4 5
$"23487":
[1] 1 2 3 4 5
$"23505":
[1] 1 2 3 4 5
$"23258":
[1] 1 2
$"23425":
[1] 1 2 3 4 5
$"23630":
[1] 1 2 3 4 5
$"6061":
[1] 1 2 3 4 5
$"23120":
[1] 1 2
$"23191":
[1] 1 2
This output gave the correct results, but I can not manage to get transform
such list into a dataframe, or maybe there is other ways around to get the
expected result.
Anyhelp would be very wellcome,
Thanks a lot,
Vincent
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