[R] aggregate output to data frame

[jim holtman]

You can also use 'dplyr'

library(tidyverse)
result <- pcr %>%
  group_by(Gene, Type, Rep) %>%
  summarise(mean = mean(Ct),
                   sd = sd(Ct),
                   oth = sd(Ct) / sqrt(sd(Ct))
  )

Jim Holtman
*Data Munger Guru*


*What is the problem that you are trying to solve?Tell me what you want to
do, not how you want to do it.*


On Wed, Mar 27, 2019 at 7:40 PM Jim Lemon <drjimlemon using gmail.com> wrote:

> Hi Cyrus,
> Try this:
>
> pcr<-data.frame(Ct=runif(66,10,20),Gene=rep(LETTERS[1:22],3),
>  Type=rep(c("Std","Unkn"),33),Rep=rep(1:3,each=22))
> testagg<-aggregate(pcr$Ct,c(pcr["Gene"],pcr["Type"],pcr["Rep"]),
>  FUN=function(x){c(mean(x), sd(x), sd(x)/sqrt(sd(x)))})
> nxcol<-dim(testagg$x)[2]
> newxs<-paste("x",1:nxcol,sep="")
> for(col in 1:nxcol)
>  testagg[[newxs[col]]]<-testagg$x[,col]
> testagg$x<-NULL
>
> Jim
>
> On Thu, Mar 28, 2019 at 12:39 PM cir p via R-help <r-help using r-project.org>
> wrote:
> >
> > Dear users,
> > i am trying to summarize data using "aggregate" with the following
> command:
> >
> >
> aggregate(pcr$Ct,c(pcr["Gene"],pcr["Type"],pcr["Rep"]),FUN=function(x){c(mean(x),
> sd(x), sd(x)/sqrt(sd(x)))})
> >
> > and the structure of the resulting data frame is
> >
> > 'data.frame':    66 obs. of  4 variables:
> > $ Gene: Factor w/ 22 levels "14-3-3e","Act5C",..: 1 2 3 4 5 6 7 8 9 10
> ...
> > $ Type: Factor w/ 2 levels "Std","Unkn": 2 2 2 2 2 2 2 2 2 2 ...
> > $ Rep : int  1 1 1 1 1 1 1 1 1 1 ...
> >  $ x   : num [1:66, 1:3] 16.3 16.7 18.2 17.1 18.6 ...
> >
> > The actual data is "bundled" in a matrix $x of the data frame. I would
> like to have the columns of this matrix as individual numeric columns in
> the same data frame instead of a matrix, but cant really figure it out how
> to do this in an efficient way. Could someone help me with the construction
> of this?
> >
> > Thanks a lot,
> >
> > Cyrus
> >
> > ______________________________________________
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> > and provide commented, minimal, self-contained, reproducible code.
>
> ______________________________________________
> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.
>

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