R help - May 2007 - Number of NA's in every second column

Hi R-users,

How do I calculate a number of NA's in a row of every second column in my
data frame?

As a starting point:
dfr <- data.frame(sapply(x, function(x) sample(0:x, 6, replace = TRUE)))
dfr[dfr==0] <- NA

So, I would like to count the number of NA in row one, two, three etc. of
columns X1, X3, X5 etc.

Thanks in advance
Lauri

	[[alternative HTML version deleted]]

for data.frames try:

rowSums(sapply(dfr, is.na))

whereas for matrices you could use:

rowSums(is.na(mat))


I hope it helps.

Best,
Dimitris

----
Dimitris Rizopoulos
Ph.D. Student
Biostatistical Centre
School of Public Health
Catholic University of Leuven

Address: Kapucijnenvoer 35, Leuven, Belgium
Tel: +32/(0)16/336899
Fax: +32/(0)16/337015
Web: http://med.kuleuven.be/biostat/
      http://www.student.kuleuven.be/~m0390867/dimitris.htm


Quoting Lauri Nikkinen <lauri.nikkinen at iki.fi>:
> Hi R-users,
>
> How do I calculate a number of NA's in a row of every second column in
my
> data frame?
>
> As a starting point:
> dfr <- data.frame(sapply(x, function(x) sample(0:x, 6, replace = TRUE)))
> dfr[dfr==0] <- NA
>
> So, I would like to count the number of NA in row one, two, three etc. of
> columns X1, X3, X5 etc.
>
> Thanks in advance
> Lauri
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at stat.math.ethz.ch 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.
>
>


Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm

sorry but I misread the part about every second column of the  
data.frame; in this case you could use:

rowSums(sapply(dfr[seq(1, length(dfr), 2)], is.na))

I hope it helps.

Best,
Dimitris


-- 
Dimitris Rizopoulos
Ph.D. Student
Biostatistical Centre
School of Public Health
Catholic University of Leuven

Address: Kapucijnenvoer 35, Leuven, Belgium
Tel: +32/(0)16/336899
Fax: +32/(0)16/337015
Web: http://med.kuleuven.be/biostat/
      http://www.student.kuleuven.be/~m0390867/dimitris.htm


Quoting Lauri Nikkinen <lauri.nikkinen at iki.fi>:
> Hi R-users,
>
> How do I calculate a number of NA's in a row of every second column in
my
> data frame?
>
> As a starting point:
> dfr <- data.frame(sapply(x, function(x) sample(0:x, 6, replace = TRUE)))
> dfr[dfr==0] <- NA
>
> So, I would like to count the number of NA in row one, two, three etc. of
> columns X1, X3, X5 etc.
>
> Thanks in advance
> Lauri
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at stat.math.ethz.ch 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.
>
>


Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm