Hello,
A simple question perhaps, but how do I, within each row, find the first
occurence of the number 1 in the df below? I want to use this position to
programmatically create the variable 'year'. I'v come up with a
solution, but I
find it downright ugly. Is there a simpler way? I was hoping for a useful
built-in function that I don;t yet know about.
df <- data.frame(j1999=c(0,0,0,0,1,0), j2000=c(NA, 1, 1, 1, 0, 0), j2001=c(1,
0,
1, 0, 0, 0), year=c(2001, 2000, 2000, 2000, 1999, NA))
library(gsubfn)
x <- apply(df==1, 1, which)
giveYear <- function(df) { return( as.numeric(gsubfn("^[^0-9]+",
"",
names(df)[1])) ) }
df$year2 <- sapply(x, giveYear)
Thanks in advance!
Cheers!!
Albert-Jan
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
All right, but apart from the sanitation, the medicine, education, wine, public
order, irrigation, roads, a fresh water system, and public health, what have the
Romans ever done for us?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[[alternative HTML version deleted]]
another approach is:
df <- data.frame(j1999 = c(0,0,0,0,1,0), j2000 = c(NA,1,1,1,0,0),
j2001 = c(1,0,1,0,0,0))
years <- as.numeric(gsub("^[^0-9]+", "", names(df)))
ind <- apply(sapply(df, "==", 1), 1, function (x) which(x)[1])
df$year <- years[ind]
I hope it helps.
Best,
Dimitris
On 5/4/2011 1:52 PM, Albert-Jan Roskam wrote:> Hello,
>
> A simple question perhaps, but how do I, within each row, find the first
> occurence of the number 1 in the df below? I want to use this position to
> programmatically create the variable 'year'. I'v come up with a
solution, but I
> find it downright ugly. Is there a simpler way? I was hoping for a useful
> built-in function that I don;t yet know about.
>
> df<- data.frame(j1999=c(0,0,0,0,1,0), j2000=c(NA, 1, 1, 1, 0, 0),
j2001=c(1, 0,
> 1, 0, 0, 0), year=c(2001, 2000, 2000, 2000, 1999, NA))
> library(gsubfn)
> x<- apply(df==1, 1, which)
> giveYear<- function(df) { return(
as.numeric(gsubfn("^[^0-9]+", "",
> names(df)[1])) ) }
> df$year2<- sapply(x, giveYear)
>
> Thanks in advance!
>
> Cheers!!
> Albert-Jan
>
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> All right, but apart from the sanitation, the medicine, education, wine,
public
> order, irrigation, roads, a fresh water system, and public health, what
have the
> Romans ever done for us?
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> 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.
>
--
Dimitris Rizopoulos
Assistant Professor
Department of Biostatistics
Erasmus University Medical Center
Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands
Tel: +31/(0)10/7043478
Fax: +31/(0)10/7043014
Web: http://www.erasmusmc.nl/biostatistiek/
You may want to look into the function 'match', which finds the first occurrence of a value. In your example, df <- data.frame(j1999=c(0,0,0,0,1,0), j2000=c(NA, 1, 1, 1, 0, 0), j2001=c(1, 0, 1, 0, 0, 0), year=c(2001, 2000, 2000, 2000, 1999, NA)) apply(df,1,match,x=1) [1] 3 2 2 2 1 NA _______________________ Patrick Breheny Assistant Professor Department of Biostatistics Department of Statistics University of Kentucky On 05/04/2011 07:52 AM, Albert-Jan Roskam wrote:> Hello, > > A simple question perhaps, but how do I, within each row, find the first > occurence of the number 1 in the df below? I want to use this position to > programmatically create the variable 'year'. I'v come up with a solution, but I > find it downright ugly. Is there a simpler way? I was hoping for a useful > built-in function that I don;t yet know about. > > df<- data.frame(j1999=c(0,0,0,0,1,0), j2000=c(NA, 1, 1, 1, 0, 0), j2001=c(1, 0, > 1, 0, 0, 0), year=c(2001, 2000, 2000, 2000, 1999, NA)) > library(gsubfn) > x<- apply(df==1, 1, which) > giveYear<- function(df) { return( as.numeric(gsubfn("^[^0-9]+", "", > names(df)[1])) ) } > df$year2<- sapply(x, giveYear) > > Thanks in advance! > > Cheers!! > Albert-Jan > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > All right, but apart from the sanitation, the medicine, education, wine, public > order, irrigation, roads, a fresh water system, and public health, what have the > Romans ever done for us? > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > [[alternative HTML version deleted]] > > ______________________________________________ > 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.