[R] can this be simplified with purrr:map or mapply?

[PIKAL Petr]

Hi

Let me make some assumptions. Your data are stored as *txt files somewhere.

I would start with vector of file names

fil<-paste0("data",2004:2014,".txt")
> fil
 [1] "data2004.txt" "data2005.txt" "data2006.txt" "data2007.txt" "data2008.txt"
 [6] "data2009.txt" "data2010.txt" "data2011.txt" "data2012.txt" "data2013.txt"
[11] "data2014.txt"

than I would read my files into predefined list

mylist<-vector(length=11, mode="list")

You can add names to this list by
names(mylist) <- fil

Than simple cycle

for (i in seq_along(fil)) {

mylist[[i]] <- read.table(fil[i])

... you could also do some polishing of single files here
}

Now you have list of data frames and you can do many operations on this whole list instead on separate data frames.

Further operations depend on structure of your data frames and your exact intention what do you want to do with them.

I wonder why merge is appropriate if you have separate data for each year. Why not to use rbind followed by aggregate.

But here I am fishing in really murky water.

Cheers
Petr


> -----Original Message-----
> From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of Brandon
> Payne
> Sent: Wednesday, January 18, 2017 10:57 AM
> To: r-help at r-project.org
> Subject: [R] can this be simplified with purrr:map or mapply?
>
> I can't get my head around the *apply family of functions,
> surely there's a better way than what I have.
> I've tried using paste0 on the years, but then I have lists of strings, not
> data frames.
>
> `realList<-paste0("exp",as.character(2004:2014),"s")`
>
> I can't seem to convert these lists of strings to references to data frames.
>
> years<-c(2004:2014)
> framesEXP<-
> list(exp2004s,exp2005s,exp2006s,exp2007s,exp2008s,exp2009s,exp2011s,ex
> p2010s,exp2012s,exp2013s,exp2014s)
>
> framesFAM<-
> list(fam2004s,fam2005s,fam2006s,fam2007s,fam2008s,fam2009s,fam2011s,fa
> m2010s,fam2012s,fam2013s,fam2014s)
>
> data2004<<-merge(exp2004s,fam2004s, by="HHNUM")
> data2005<<-merge(exp2005s,fam2005s, by="HHNUM")
> data2006<<-merge(exp2006s,fam2006s, by="HHNUM")
> data2007<<-merge(exp2007s,fam2007s, by="HHNUM")
> data2008<<-merge(exp2008s,fam2008s, by="HHNUM")
> data2009<<-merge(exp2009s,fam2009s, by="HHNUM")
> data2010<<-merge(exp2010s,fam2010s, by="HHNUM")
> data2011<<-merge(exp2011s,fam2011s, by="HHNUM")
> data2012<<-merge(exp2012s,fam2012s, by="HHNUM")
> data2013<<-merge(exp2013s,fam2013s, by="HHNUM")
> data2014<<-merge(exp2014s,fam2014s, by="HHNUM")
>
> dput(data2004, file="../dataframes/data2004.txt")
> dput(data2005, file="../dataframes/data2005.txt")
> dput(data2006, file="../dataframes/data2006.txt")
> dput(data2007, file="../dataframes/data2007.txt")
> dput(data2008, file="../dataframes/data2008.txt")
> dput(data2009, file="../dataframes/data2009.txt")
> dput(data2010, file="../dataframes/data2010.txt")
> dput(data2011, file="../dataframes/data2011.txt")
> dput(data2012, file="../dataframes/data2012.txt")
> dput(data2013, file="../dataframes/data2013.txt")
> dput(data2014, file="../dataframes/data2014.txt")
>
>       [[alternative HTML version deleted]]
>
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