Hi Ista,
Thanks for your suggestion, I am still trying to wrap my head around the
functions you used, as I am not familiar with any of them, but it works
perfectly!
I do want to understand the code, if you don't mind I would like to ask a
few questions
In this line:
dfm <- melt(df[c(1, 2, 5, 8)], id = 1)
What does the id=1 do? The variables are already specified in df[c(1, 2, 5,
8)], right?
What does this line do:
dfm.r <- ddply(dfm.r, .(name), transform, index = paste("S",
1:length(name), sep = ""))
Thanks again for the help.
Laura
On Thu, Aug 11, 2011 at 5:57 PM, Ista Zahn <iz...@psych.rochester.edu>wrote:
> Hi Laura,
>
> On Thu, Aug 11, 2011 at 7:01 AM, Lali <laur...@gmail.com> wrote:
> > Hi everyone,
> > I have a data frame that looks *sort of* like this:
> >
> > name <- letters[1:5]
> > signal.1 <- c("12", "bad signal", "noise", "10", "X")
> > length.signal.1 <- 5:9
> > intensity.signal.1 <- 3:7
> > signal.2 <- c("13", "noise", "19.2", "X", "V")
> > length.signal.2 <- 2:6
> > intensity.signal.2 <- 1:5
> > signal.3 <- c("NA", "15.4", "error", "NA", "17")
> > length.signal.3 <- c("NA", 2, 3, "NA", 4)
> > intensity.signal.3 <- c("NA",4, 5, "NA", 5)
> >
> > #(there are actually up to 16 signals and 50 names, but I made this short
> > for the example)
> >
> > df <- data.frame(cbind(name, signal.1, length.signal.1,
> intensity.signal.1,
> > signal.2,
> > length.signal.2, intensity.signal.2, signal.3,
> > length.signal.3,
> > intensity.signal.3))
> >
> >
> >
> > I need to "fish out" some values and have them in a new data frame.
> >
> > I am only interested in values in columns 2, 5 and 8 (actually seq(2, 50,
> 3)
> > in my real df)
> > I want the values that are not:
> > "bad signal"
> > "noise"
> > "error"
> > "NA"
> > "V"
> >
> > This is the output I want (the name column is unimportant for my
> purposes,
> > its just there as a reference for the example).
> >
> > (name) S1 S2
> > A 12 13
> > B 15.4 (another value found in the other signals >3 not shown
> on
> > example)
> > C 19.2 (another value found in the other signals >3 not shown
> on
> > example)
> > D 10 X
> > E X 17
> >
> > I do know that there will always be 2 values exactly that do not match
> the
> > exclusions named above, or none at all
> >
> > I have tried different approaches, grep, matching,%nin%... But as I am
> not
> > an advanced used, I am very likely doing something wrong, because I
> either
> > get a vector, or I get a matrix with TRUE FALSE, and usually I get the
> whole
> > rows, and I don't want that :(
> > I have also being searching the list for answers without avail.
> > Any suggestions? Examples including syntax are appreciated (syntax is a
> > major weak point for me).
>
> Here is a solution using the reshape and plyr packages
>
> library(reshape)
> dfm <- melt(df[c(1, 2, 5, 8)], id = 1)
> dfm.r <- dfm[!dfm$value %in% c("bad signal", "noise", "error", "NA", "V"),
> ]
> dfm.r <- ddply(dfm.r, .(name), transform, index = paste("S",
> 1:length(name), sep = ""))
> cast(dfm.r, name ~ index)
>
> Best,
> Ista
> >
> >
> > Laura
> >
> > [[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.
> >
>
>
>
> --
> Ista Zahn
> Graduate student
> University of Rochester
> Department of Clinical and Social Psychology
> http://yourpsyche.org
>
[[alternative HTML version deleted]]
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