I'm trying to create a new variable (meanABUNDHA) by obtaining a mean value *by* other variables. I surveyed birds (multiple species) at multiple sites and have multiple surveys within a REP (i.e. in example data below, SURVEY 55 and 57 are in REP 11). I need the mean ABUNDHA (pooling SURVEY) for each BIRD species by REP and by SITE. Below, I would average 0.77 and 0.15 for MALL in REP 11 at SITE 1 to get 0.46 meanABUNDHA. An example of my data are as follows, including the new variable I hope to create meanABUNDHA: SITE REP SURVEY BIRD ABUNDHA meanABUNDHA 1 11 57 MALL 0.77 0.46 1 11 55 MALL 0.15 0.46 1 12 58 MALL 0.14 0.14 1 2 58 BAEA 0.03 0.03 3 4 64 AMCR 0.22 0.45 3 5 65 AMCR 0.67 0.45 7 11 56 MALL 0.01 0.01 I'm not sure how to incorporate more than one "by="? data.all4[,mean(ABUNDHA),byREP] #Add new column containing the by-REP mean of ABUNDHA data.all5<-data.all4[,ABUNDHAmean:=mean(ABUNDHA),by=REP] Thank you for any guidance!! [[alternative HTML version deleted]]
Peter Alspach
2014-Mar-10 03:40 UTC
[R] How to obtain a mean by more than one other variable
Tena koe Erynn
Have you checked tapply and aggregate?
HTH ....
Peter Alspach
-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
On Behalf Of Erynn Call
Sent: Monday, 10 March 2014 3:40 p.m.
To: r-help at r-project.org
Subject: [R] How to obtain a mean by more than one other variable
I'm trying to create a new variable (meanABUNDHA) by obtaining a mean value
*by* other variables. I surveyed birds (multiple species) at multiple sites and
have multiple surveys within a REP (i.e. in example data below, SURVEY
55 and 57 are in REP 11). I need the mean ABUNDHA (pooling SURVEY) for each
BIRD species by REP and by SITE. Below, I would average 0.77 and 0.15 for MALL
in REP 11 at SITE 1 to get 0.46 meanABUNDHA.
An example of my data are as follows, including the new variable I hope to
create meanABUNDHA:
SITE REP SURVEY BIRD ABUNDHA meanABUNDHA
1 11 57 MALL 0.77 0.46
1 11 55 MALL 0.15 0.46
1 12 58 MALL 0.14 0.14
1 2 58 BAEA 0.03 0.03
3 4 64 AMCR 0.22 0.45
3 5 65 AMCR 0.67 0.45
7 11 56 MALL 0.01 0.01
I'm not sure how to incorporate more than one "by="?
data.all4[,mean(ABUNDHA),byREP]
#Add new column containing the by-REP mean of ABUNDHA
data.all5<-data.all4[,ABUNDHAmean:=mean(ABUNDHA),by=REP]
Thank you for any guidance!!
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Andrew Koeser
2014-Mar-10 03:53 UTC
[R] How to obtain a mean by more than one other variable
One function I like is from package psych. library(psych) describe.by(ARK$TotalWater, group=Tray:Pot) Andrew Koeser On 3/9/2014 10:39 PM, Erynn Call wrote:> I'm trying to create a new variable (meanABUNDHA) by obtaining a mean value > *by* other variables. I surveyed birds (multiple species) at multiple sites > and have multiple surveys within a REP (i.e. in example data below, SURVEY > 55 and 57 are in REP 11). I need the mean ABUNDHA (pooling SURVEY) for each > BIRD species by REP and by SITE. Below, I would average 0.77 and 0.15 for > MALL in REP 11 at SITE 1 to get 0.46 meanABUNDHA. > > An example of my data are as follows, including the new variable I hope to > create meanABUNDHA: > SITE REP SURVEY BIRD ABUNDHA meanABUNDHA > 1 11 57 MALL 0.77 0.46 > 1 11 55 MALL 0.15 0.46 > 1 12 58 MALL 0.14 0.14 > 1 2 58 BAEA 0.03 0.03 > 3 4 64 AMCR 0.22 0.45 > 3 5 65 AMCR 0.67 0.45 > 7 11 56 MALL 0.01 0.01 > > I'm not sure how to incorporate more than one "by="? > > data.all4[,mean(ABUNDHA),by> REP] > > #Add new column containing the by-REP mean of ABUNDHA > data.all5<-data.all4[,ABUNDHAmean:=mean(ABUNDHA),by=REP] > > Thank you for any guidance!! > > [[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.-- Andrew Koeser, BCMA, Ph.D. Assistant Professor of Landscape Management University of Florida - Gulf Coast Research and Education Center 813-633-4150
Hi, If `dat` is the dataset: with(dat,ave(ABUNDHA,SITE,REP,FUN=mean)) #[1] 0.46 0.46 0.14 0.03 0.22 0.67 0.01 I am not sure how you got 0.45 when REP's are not the same. A.K. On Sunday, March 9, 2014 11:29 PM, Erynn Call <erynn.call at maine.edu> wrote: I'm trying to create a new variable (meanABUNDHA) by obtaining a mean value *by* other variables.? I surveyed birds (multiple species) at multiple sites and have multiple surveys within a REP (i.e. in example data below, SURVEY 55 and 57 are in REP 11).? I need the mean ABUNDHA (pooling SURVEY) for each BIRD species by REP and by SITE. Below, I would average 0.77 and 0.15 for MALL in REP 11 at SITE 1 to get 0.46 meanABUNDHA. An example of my data are as follows, including the new variable I hope to create meanABUNDHA: SITE? ? REP? ? SURVEY? BIRD? ? ABUNDHA meanABUNDHA 1? ? ? 11? ? ? ? ? ? 57? ? ? ? ? ? MALL? ? ? 0.77? ? ? ? ? ? 0.46 1? ? ? 11? ? ? ? ? ? 55? ? ? ? ? ? MALL? ? ? 0.15? ? ? ? ? ? 0.46 1? ? ? 12? ? ? ? ? ? 58? ? ? ? ? ? MALL? ? ? 0.14? ? ? ? ? ? 0.14 1? ? ? 2? ? ? ? ? ? ? 58? ? ? ? ? ? BAEA? ? 0.03? ? ? ? ? ? 0.03 3? ? ? 4? ? ? ? ? ? ? 64? ? ? ? ? ? AMCR? ? 0.22? ? ? ? ? ? 0.45 3? ? ? 5? ? ? ? ? ? ? 65? ? ? ? ? ? AMCR? ? 0.67? ? ? ? ? ? 0.45 7? ? ? 11? ? ? ? ? ? 56? ? ? ? ? ? MALL? ? ? 0.01? ? ? ? ? ? 0.01 I'm not sure how to incorporate more than one "by="? data.all4[,mean(ABUNDHA),byREP] #Add new column containing the by-REP mean of ABUNDHA data.all5<-data.all4[,ABUNDHAmean:=mean(ABUNDHA),by=REP] Thank you for any guidance!! ??? [[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.