Good morning, I would like to know if is possible somebody can help me with this please: I would like to calculate the median of grouped data, this is an example: ID PM adt_01 25.255 adt_01 225.36 adt_01 14.2325 adt_02 15 adt_02 12.3 adt_03 15.2 adt_03 148.3 adt_03 25.5 adt_03 14.25 I need the median of adt_01, 02 and 03 , I know that I have to split first my data and then ask for the median but the code I have is not working. Thank you very much if you can help me with the code maria
Tena koe Maria ?tapply Specifically: tapply(yourData$PM, yourData$ID, median) HTH .... Peter Alspach> -----Original Message----- > From: r-help-bounces at r-project.org > [mailto:r-help-bounces at r-project.org] On Behalf Of "Mar?a del > Pilar M?rquez" > Sent: Thursday, 28 January 2010 7:06 a.m. > To: r-help at r-project.org > Subject: [R] median of grouped data > > Good morning, > I would like to know if is possible somebody can help me with > this please: > I would like to calculate the median of grouped data, this is > an example: > > ID PM > adt_01 25.255 > adt_01 225.36 > adt_01 14.2325 > adt_02 15 > adt_02 12.3 > adt_03 15.2 > adt_03 148.3 > adt_03 25.5 > adt_03 14.25 > > I need the median of adt_01, 02 and 03 , I know that I have > to split first my data and then ask for the median but the > code I have is not working. > > Thank you very much if you can help me with the code maria > > ______________________________________________ > 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. >
Like this?
d = read.table(textConnection("ID PM
adt_01 25.255
adt_01 225.36
adt_01 14.2325
adt_02 15
adt_02 12.3
adt_03 15.2
adt_03 148.3
adt_03 25.5
adt_03 14.25"),head=T)
d
d$PM <- as.numeric(d$PM)
ddply(d,.(ID),numcolwise(median))
Felipe D. Carrillo
Supervisory Fishery Biologist Department of the Interior US Fish &
Wildlife Service California, USA
--- On Wed, 1/27/10, "Mar?a del Pilar M?rquez" <marquezvilla at
wisc.edu> wrote:
> From: "Mar?a del Pilar M?rquez" <marquezvilla at wisc.edu>
> Subject: [R] median of grouped data
> To: r-help at r-project.org
> Date: Wednesday, January 27, 2010, 10:05 AM
> Good morning,
> I would like to know if is possible somebody can help me
> with this please:
> I would like to calculate the median of grouped data, this
> is an example:
>
> ID? ? PM
> adt_01? 25.255
> adt_01? 225.36
> adt_01? 14.2325
> adt_02? 15
> adt_02? 12.3
> adt_03? 15.2
> adt_03? 148.3
> adt_03? 25.5
> adt_03? 14.25
>
> I need the median of adt_01, 02 and 03 , I know that I have
> to split first my data and then ask for the median but the
> code I have is not working.
>
> Thank you very much if you can help me with the code
> maria
>
> ______________________________________________
> 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.
>
Check the package doBy as well (pretty handy for analysis of grouped data). library(doBy) summaryBy(PM~ID,data=d,FUN=median) HTH, -Girish -- View this message in context: http://n4.nabble.com/median-of-grouped-data-tp1311971p1312386.html Sent from the R help mailing list archive at Nabble.com.