You can try the TkListView function from the TeachingDemos package. I have tested it with lists with about 50 elements, but not thousands, so no guarantees. It opens a new window with the elements of the list in the left pane (can be scrolled up and down), each element then has a '+' next to it that if you click on it will show the next level down of just that element. There are buttons to further explore (print/str/custom) the currently selected element.
You can also just do str or whatever on single elements: > str(mylist[[5]]) Will give the details on the 5th element of mylist. Hope this helps, -- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare [EMAIL PROTECTED] 801.408.8111 > -----Original Message----- > From: tsunhin wong [mailto:[EMAIL PROTECTED] > Sent: Tuesday, December 09, 2008 4:22 PM > To: Greg Snow > Cc: r-help@r-project.org > Subject: Re: [R] Transforming a string to a variable's name? help me > newbie... > > I did really want to find make the suggestion work... it is going to > save my time... > I worked on trying to put all dataframes into a list() by: > ###start of file > rm(list=ls()) > setwd("/Users/John/Programs/R") > load("Expt108Master2008.Rdata") > > nms <- ls(pattern=".data") > my.data <- list() > for(i in nms) my.data[[i]] <- get(i) > > save(list=ls(pattern="my."), file="Expt108One.Rdata") > ###end of file > > The original Rdata file (with global dataframes) is 427.4Mb, and the > new Rdata file with 1 list() storing all dataframes is 427.2Mb > I can now access the individual dataframes by: > my.data$019v1msa1.data > > But... > At the moment, whenever I type > >my.data > then the whole huge list of dataframes just flush out of standard > output... and doing a > >dim(my.data) > will give me only NULL... > what command(s) allows me to look at what variables / dataframes are > stored in a list() structure? And how many of them is there? > > Thanks a lot! I'm still seasoning my style of working in R! > > Regards, > > John > > On Mon, Dec 8, 2008 at 4:10 PM, Greg Snow <[EMAIL PROTECTED]> wrote: > > I really don't understand your concern. Something like: > > > >> nms <- c('file1','file2','file3') > >> my.data <- list() > >> for (i in nms) my.data[[ i ]] <- read.table(i) > > > > Will read in the files listed in the nms vector and put them into the > list my.data (each data frame is a single element of the list). This > list will not take up about the same amount of memory as if you read > each file into a dataframe in the global environment. And there is no > transforming of data frames (into 1 row or otherwise). > > > > -- > > Gregory (Greg) L. Snow Ph.D. > > Statistical Data Center > > Intermountain Healthcare > > [EMAIL PROTECTED] > > 801.408.8111 > > > > > >> -----Original Message----- > >> From: tsunhin wong [mailto:[EMAIL PROTECTED] > >> Sent: Monday, December 08, 2008 1:34 PM > >> To: Greg Snow > >> Cc: Jim Holtman; r-help@r-project.org; [EMAIL PROTECTED] > >> Subject: Re: [R] Transforming a string to a variable's name? help me > >> newbie... > >> > >> I want to combine all dataframes into one large list too... > >> But each dataframe is a 35 columns x varying number of rows > structure > >> (from 2000 to >9000 rows) > >> I have ~1500 dataframes of these to process, and that add up to > > >> 1.5Gb of data... > >> > >> Combining dataframes into a single one require me to transform each > >> single dataframe into one line, but I really don't have a good > >> solution for the varying number of rows scenario... And also, I > don't > >> want to stall my laptop every time I run the data set: maybe I can > do > >> that when my prof give me a ~ 4Gb ram desktop to run the script ;) > >> > >> Thanks! :) > >> > >> - John > >> > >> On Mon, Dec 8, 2008 at 1:36 PM, Greg Snow <[EMAIL PROTECTED]> > wrote: > >> > In the long run it will probably make your life much easier to > read > >> all the dataframes into one large list (and have the names of the > >> elements be what your currently name the dataframes), then you can > just > >> use regular list indexing (using [[]] rather than $ in most cases) > >> instead of having to worry about get and assign and the > >> risks/subtleties involved in using those. > >> > > >> > Hope this helps, > >> > > >> > -- > >> > Gregory (Greg) L. Snow Ph.D. > >> > Statistical Data Center > >> > Intermountain Healthcare > >> > [EMAIL PROTECTED] > >> > 801.408.8111 > >> > > >> > > >> >> -----Original Message----- > >> >> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > >> >> project.org] On Behalf Of tsunhin wong > >> >> Sent: Monday, December 08, 2008 8:45 AM > >> >> To: Jim Holtman > >> >> Cc: r-help@r-project.org > >> >> Subject: Re: [R] Transforming a string to a variable's name? help > me > >> >> newbie... > >> >> > >> >> Thanks Jim and All! > >> >> > >> >> It works: > >> >> tmptrial <- trialcompute(trialextract( > >> >> get(paste("t",tmptrialinfo[1,2],tmptrialinfo[1,16],".gz",sep="")) > , > >> >> tmptrialinfo[1,32],secs,sdm),secs,binsize) > >> >> > >> >> Can I use "assign" instead? How should it be coded then? > >> >> > >> >> Thanks! > >> >> > >> >> - John > >> >> > >> >> On Mon, Dec 8, 2008 at 10:40 AM, Jim Holtman <[EMAIL PROTECTED]> > >> >> wrote: > >> >> > ?get > >> >> > > >> >> > > >> >> > Sent from my iPhone > >> >> > > >> >> > On Dec 8, 2008, at 7:11, "tsunhin wong" <[EMAIL PROTECTED]> > wrote: > >> >> > > >> >> >> Dear all, > >> >> >> > >> >> >> I'm a newbie in R. > >> >> >> I have a 45x2x2x8 design. > >> >> >> A dataframe stores the metadata of trials. And each trial has > its > >> >> own > >> >> >> data file: I used "read.table" to import every trial into R as > a > >> >> >> dataframe (variable). > >> >> >> > >> >> >> Now I dynamically ask R to retrieve trials that fit certain > >> >> selection > >> >> >> criteria, so I use "subset", e.g. > >> >> >> tmptrialinfo <- subset(trialinfo, (Subject==24 & > >> >> Filename=="v2msa8")) > >> >> >> > >> >> >> The name of the dataframe / variable of an individual trial > can > >> be > >> >> >> obtained using: > >> >> >> paste("t",tmptrialinfo[1,2],tmptrialinfo[1,16],".gz",sep="") > >> >> >> Then I get a string: > >> >> >> "t24v2msa8.gz" > >> >> >> which is of the exact same name of the dataframe / variable of > >> that > >> >> >> trial, which is: > >> >> >> t24v2msa8.gz > >> >> >> > >> >> >> Can somebody tell me how can I change that string (obtained > from > >> >> >> "paste()" above) to be a usable / manipulable variable name, > so > >> that > >> >> I > >> >> >> can do something, such as: > >> >> >> (1) > >> >> >> tmptrial <- trialcompute(trialextract( > >> >> >> paste("t",tmptrialinfo[1,2],tmptrialinfo[1,16],".gz",sep="") > >> >> >> ,tmptrialinfo[1,32],secs,sdm),secs,binsize) > >> >> >> instead of hardcoding: > >> >> >> (2) > >> >> >> tmptrial <- > >> >> >> > >> >> > >> > trialcompute(trialextract(t24v2msa8.gz,tmptrialinfo[1,32],secs,sdm),sec > >> >> s,binsize) > >> >> >> > >> >> >> Currently, 1) doesn't work... > >> >> >> > >> >> >> Thanks in advance for your help! > >> >> >> > >> >> >> Regards, > >> >> >> > >> >> >> John > >> >> >> > >> >> >> ______________________________________________ > >> >> >> 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. > >> >> > > >> >> > >> >> ______________________________________________ > >> >> 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. > >> > > > ______________________________________________ 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.
