Look at ?by for example
by(data=v2, INDICES=v1, FUN=median, na.rm=TRUE) This will calculate the median of v2 (age) for each level of the indices v1 (in your case M and F). If you are only interested the median for a single level, Mohamed's solution is simpler. Josh On Wed, Apr 21, 2010 at 8:10 AM, Vlatka Matkovic Puljic <v.matkovic.pul...@gmail.com> wrote: > I have additional Q: > > v1 is gender (M=1 and F=2) > v2 is age > > I want R to calculate median only for M (1), > but my comand is not good :) > > while(v1=1){median(v2,na.rm=TRUE)} > Error: unexpected '=' in "while(Q2=" > > 2010/4/21 Vlatka Matkovic Puljic <v.matkovic.pul...@gmail.com> >> >> Thank you! >> >> 2010/4/21 Joshua Wiley <jwiley.ps...@gmail.com> >>> >>> Hello, >>> >>> summary() removes NAs by default. You can get the same results using >>> >>> median(year, na.rm=TRUE) >>> >>> see ?median >>> >>> HTH, >>> >>> Josh >>> >>> On Wed, Apr 21, 2010 at 6:40 AM, Vlatka Matkovic Puljic >>> <v.matkovic.pul...@gmail.com> wrote: >>> > Hi, >>> > >>> > I have dataset n1 and v1 (years). >>> > when i ask >>> > median(year) >>> > [1] NA >>> > >>> > but if i put summary of dataset n1: >>> > summary(n1) >>> > R produces median (together with min/max/mean....) >>> > >>> > why it is so? >>> > >>> > >>> > -- >>> > ************************** >>> > Vlatka Matkovic Puljic >>> > 095/8618 171 >>> > >>> > [[alternative HTML version deleted]] >>> > >>> > ______________________________________________ >>> > R-help@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. >>> > >>> >>> >>> >>> -- >>> Joshua Wiley >>> Senior in Psychology >>> University of California, Riverside >>> http://www.joshuawiley.com/ >> >> >> >> -- >> ************************** >> Vlatka Matkovic Puljic >> 095/8618 171 > > > > -- > ************************** > Vlatka Matkovic Puljic > 095/8618 171 > -- Joshua Wiley Senior in Psychology University of California, Riverside http://www.joshuawiley.com/ ______________________________________________ R-help@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.