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Count values in a dataframe with respect to groups

7 messages · Henrique Dallazuanna, Marcus Drescher, ONKELINX, Thierry +1 more

Original
Marcus Drescher
# 
Dear all,

I am looking for a function to count values belonging to a class within a dataframe (and ignore NAs).

grp = c(1,1,1, 1,2, 2,2)
val = c(2,1,5,NA,3,NA,1)

dta = data.frame(grp=grp, val=val)

The result should look like:

grp count
 1    3
 2    2

At the moment, I am trying to find a function for FUN in aggregate, but with no success. Can anybody help me?

Thanks in advance.
Marcus
Marcus Drescher
# 
Thanks! It works great.

One more question: how would I have to set the formula if I would have the columns to count (val1 and val2)?


Betreff: Re: [R] Count values in a dataframe with respect to groups

Try this:

aggregate(val ~ grp, dta, length)
On Fri, Oct 8, 2010 at 11:28 AM, Marcus Drescher <drescher at tum.de> wrote:
Dear all,

I am looking for a function to count values belonging to a class within a dataframe (and ignore NAs).

grp = c(1,1,1, 1,2, 2,2)
val = c(2,1,5,NA,3,NA,1)

dta = data.frame(grp=grp, val=val)

The result should look like:

grp count
?1 ? ?3
?2 ? ?2

At the moment, I am trying to find a function for FUN in aggregate, but with no success. Can anybody help me?

Thanks in advance.
Marcus

______________________________________________
R-help at r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
ONKELINX, Thierry
# 
Have a look at table

table(na.omit(dta)$grp)

Untested!

------------------------------------------------------------------------
----
ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek
team Biometrie & Kwaliteitszorg
Gaverstraat 4
9500 Geraardsbergen
Belgium

Research Institute for Nature and Forest
team Biometrics & Quality Assurance
Gaverstraat 4
9500 Geraardsbergen
Belgium

tel. + 32 54/436 185
Thierry.Onkelinx at inbo.be
www.inbo.be

To call in the statistician after the experiment is done may be no more
than asking him to perform a post-mortem examination: he may be able to
say what the experiment died of.
~ Sir Ronald Aylmer Fisher

The plural of anecdote is not data.
~ Roger Brinner

The combination of some data and an aching desire for an answer does not
ensure that a reasonable answer can be extracted from a given body of
data.
~ John Tukey
Marcus Drescher
# 
I am sorry for the typo, it is about counting two columns an skipping the NAs.

How would I have to set the formula if I would have two columns to count (val1 and val2)?


Betreff: Re: [R] Count values in a dataframe with respect to groups

Try this:

aggregate(val ~ grp, dta, length)
On Fri, Oct 8, 2010 at 11:28 AM, Marcus Drescher <drescher at tum.de> wrote:
Dear all,

I am looking for a function to count values belonging to a class within a dataframe (and ignore NAs).

grp = c(1,1,1, 1,2, 2,2)
val = c(2,1,5,NA,3,NA,1)

dta = data.frame(grp=grp, val=val)

The result should look like:

grp count
?1 ? ?3
?2 ? ?2

At the moment, I am trying to find a function for FUN in aggregate, but with no success. Can anybody help me?

Thanks in advance.
Marcus

______________________________________________
R-help at r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Felipe Carrillo
# 
Here is an option:

grp = c(1,1,1, 1,2, 2,2)
?val = c(2,1,5,NA,3,NA,1)
?dta = data.frame(grp=grp, val=val)
ddply(dta,"grp",summarise,count=length(na.omit(val)))
?
Felipe D. Carrillo
Supervisory Fishery Biologist
Department of the Interior
US Fish & Wildlife Service
California, USA



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