Hi Arun,
Thanks a lot for the help. I think I didn't make my request clear, though;
sorry about that. What your example does is applies the values of y to each
element in the list "result". However, what I'm actually trying to do is
apply the nth element of y to the nth element of result. In other words,
I'm trying to find a way in one command to do the equivalent of the
following:
result[[1]][[1]]$Thing <- y[1]
result[[2]][[1]]$Thing <- y[2]
...etc.
Is this even possible? (Granted, for my purpose "result" is not a very long
list, so it would not be difficult to just do those commands one at a time
or in a for loop. At this point I'm just curious to figure out a more
straightforward way to do it just for the sake of trying to learn more
about how R works!)
If it helps put things into context, in my example the list "result" is a
summary of an aov object, and each element in the list is one of the ANOVA
effects; y is a vector of the partial eta squareds I calculated
corresponding to each effect, and I'm trying to figure out a way to add
those into the "result" object so it shows up when my colleague looks at
the summary.
Best,
Steve
On Sat, Nov 24, 2012 at 5:22 PM, arun <smartpink...@yahoo.com> wrote:
> HI,
>
> The example data you gave have only one row for the 1st element of list.
> So, it would be better to add it as:
> lapply(result,function(x) {x[[2]]<-y
> return(x)})
> #$`Error: subject`
> #Component 1 :
> # Df Sum Sq Mean Sq F value Pr(>F)
> #Residuals 4 12.4 3.1
> #
> #Component 2 :
> #[1] 0.5000000 0.7724138
> -----------------------------
> You can also do:
> lapply(result,function(x) {x[[1]][6]<-y[1]
> x[[1]][7]<-y[2]
> return(x)})
> #$`Error: subject`
> # Df Sum Sq Mean Sq F value Pr(>F) V6 V7
> #Residuals 4 12.4 3.1 0.5 0.7724
>
> #$`Error: subject:myfactor`
> # Df Sum Sq Mean Sq F value Pr(>F) V6 V7
> #myfactor 2 14.93 7.467 13.58 0.002683 0.5 0.7724
> #Residuals 8 4.40 0.550 0.5 0.7724 #Here it got
> repeated
>
> May be there are better methods
>
> A.K.
>
>
>
>
>
> ----- Original Message -----
> From: Stephen Politzer-Ahles <politzerahl...@gmail.com>
> To: r-help@r-project.org
> Cc:
> Sent: Saturday, November 24, 2012 5:33 PM
> Subject: [R] Adding a new variable to each element of a list
>
> Hello,
>
> I have a list of data with multiple elements, and each element in the list
> has multiple variables in it. Here's an example:
>
> ### Make the fake data
> dv <- c(1,3,4,2,2,3,2,5,6,3,4,4,3,5,6)
> subject <- factor(c("s1","s1","s1","s2","s2","s2","s3","s3","s3",
> "s4","s4","s4","s5","s5","s5"))
> myfactor <- factor(c("f1","f2","f3","f1","f2","f3","f1","f2","f3",
> "f1","f2","f3","f1","f2","f3"))
> mydata <- data.frame(dv, subject, myfactor)
>
> ### Do the anova and store the summary in "result"
> mydata.aov <- aov( dv ~ myfactor + Error(subject/myfactor), mydata )
> ( result <- summary( mydata.aov ) ) # see the anova
>
> str(result)
>
> List of 2
> $ Error: subject :List of 1
> ..$ :Classes âanovaâ and 'data.frame': 1 obs. of 5 variables:
> .. ..$ Df : num 4
> .. ..$ Sum Sq : num 12.4
> .. ..$ Mean Sq: num 3.1
> .. ..$ F value: num NA
> .. ..$ Pr(>F) : num NA
> ..- attr(*, "class")= chr [1:2] "summary.aov" "listof"
> $ Error: subject:myfactor:List of 1
> ..$ :Classes âanovaâ and 'data.frame': 2 obs. of 5 variables:
> .. ..$ Df : num [1:2] 2 8
> .. ..$ Sum Sq : num [1:2] 14.9 4.4
> .. ..$ Mean Sq: num [1:2] 7.47 0.55
> .. ..$ F value: num [1:2] 13.6 NA
> .. ..$ Pr(>F) : num [1:2] 0.00268 NA
> ..- attr(*, "class")= chr [1:2] "summary.aov" "listof"
>
> As you can see, each element in "result" has several variables (Df, Sum Sq,
> Mean Sq, F value, Pr(>F)):
> str( result[[2]][[1]] )
> Classes âanovaâ and 'data.frame': 2 obs. of 5 variables:
> $ Df : num 2 8
> $ Sum Sq : num 14.9 4.4
> $ Mean Sq: num 7.47 0.55
> $ F value: num 13.6 NA
> $ Pr(>F) : num 0.00268 NA
>
> Now I also have another vector of numbers that I would like to add to the
> list, as a 6th variable for each element:
> y <- c(.5, .7724138)
>
> Ideally, I would like each element in the list ("Error: subject" and
> "Error: subject:myfactor") to have a 6th variable, so the new str() would
> look like:
> List of 2
> $ Error: subject :List of 1
> ..$ :Classes âanovaâ and 'data.frame': 1 obs. of 5 variables:
> .. ..$ Df : num 4
> .. ..$ Sum Sq : num 12.4
> .. ..$ Mean Sq: num 3.1
> .. ..$ F value: num NA
> .. ..$ Pr(>F) : num NA
> * .. ..$ Thing : num 0.50*
> ..- attr(*, "class")= chr [1:2] "summary.aov" "listof"
> $ Error: subject:myfactor:List of 1
> ..$ :Classes âanovaâ and 'data.frame': 2 obs. of 5 variables:
> .. ..$ Df : num [1:2] 2 8
> .. ..$ Sum Sq : num [1:2] 14.9 4.4
> .. ..$ Mean Sq: num [1:2] 7.47 0.55
> .. ..$ F value: num [1:2] 13.6 NA
> .. ..$ Pr(>F) : num [1:2] 0.00268 NA
> *.. ..$ Thing : num **0.772413*
> ..- attr(*, "class")= chr [1:2] "summary.aov" "listof"
>
> Now, I know how to do this if I want to just add the variable to one
> element at a time:
> result[[1]][[1]]$Thing <- 0.5
>
> But I can't figure out how to do it for every element at once (other than
> using a for loop). I am able to index an existing variable from each
> element of a list (using lapply or sapply, based on the examples from
>
> http://stackoverflow.com/questions/1355355/how-to-avoid-a-loop-in-r-selecting-items-from-a-listand
> http://tolstoy.newcastle.edu.au/R/help/05/05/4678.html), but I can't
> figure
> out how to *set* a new variable for each element in a list. Does anyone
> know how to do this?
>
> Thank you,
> Steve Polizer-Ahles
>
> --
> Stephen Politzer-Ahles
> University of Kansas
> Linguistics Department
> http://people.ku.edu/~sjpa/
>
> [[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.
>
>
--
Stephen Politzer-Ahles
University of Kansas
Linguistics Department
http://people.ku.edu/~sjpa/
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