similar to: how do I find the row index number, or row name, of a given value in a vector?

Hi all, So let's say I have a matrix, mdat and I only know the index number. How do I retrieve the column and row names? For example, > mdat <- matrix(c(1,2,3, 11,12,13), nrow = 2, ncol=3, byrow=TRUE, dimnames = list(c("row1", "row2"), c("C.1", "C.2", "C.3"))) > mdat[4] [1] 12 >

So imagine I have a vector: zz = c("a","c","d","b") and another vector: xx = c("d","c","a","b") I need to get xx in the same order as zz. I am sure this is very simple but I can't figure it out from the help pages for order or sort. Perhaps I'm not trying hard enough but its been bugging me for a while....

For example, c("dog.is.an.animal", "cat.is.an.animal", "rat.is.an.animal"). How can I identify the common prefix is ".is.an.animal" and delete it to give c("dog", "cat", "rat") ? Thanks _________________________________________________________________ [[alternative HTML version deleted]]

I have the following sample dataset (CSV input here:http://goo.gl/YR8LP. CSV output here: http://goo.gl/EFCC8) which I want to transform as follows. For each person in a household I want to create two new variables OrigTAZ and DestTAZ. It should take the value in TripendTAZ and put that in DestTAZ. For OrigTAZ it should put value of TripendTAZ from the previous row. For the first trip of every

I found: max.col(matrix(c(1,3,2),nrow=1)) Is there a more concise/elegant way? Thanks, ----- TO GET MORE DETAILS CLICK HERE -- View this message in context: http://r.789695.n4.nabble.com/finding-index-of-maximum-value-in-vector-tp4651663.html Sent from the R help mailing list archive at Nabble.com.

Hi, Hopefully someone can point me in the right direction on how I would go about solving the following. I have some data and need to find the column name of the maximum value in each row. This could be the data... > a <- data.frame(x = rnorm(4), y = rnorm(4), z = rnorm(4)) > a x y z 1 1.6534561 0.11523404 0.2261730 2 -1.2274320 -0.24096054 1.5096028

Hi, I would like to use a weighted lm model to reduce heteroscendasticity. I am wondering if the only way to generate the weights in R is through the laborious process of trial and error by hand. Does anyone know if R has a function that would automatically generate the weights need for lm? Thanks, -- Tom [[alternative HTML version deleted]]

In general, how can I increase a vector of length m (< n) to length n by padding it with m - n missing values, without losing attributes? The two approaches I've tried, using length<- and adding missings with c, do not work in general: > a <- as.Date("2008-01-01") > c(a, NA) [1] "2008-01-01" NA > length(a) <- 2 > a [1] 13879 NA > b <-

I have a server with 4 nics. Two are using different internet connections, both with static IP's, and two are connected to our private network. The two internet facing nics seem to be battling over the gateway designation. Which ever I designate as the gateway the other stops responding to incoming traffic. I need both to listen to inbound traffic. One for our main web page and the other

Hi, I need to correct for ar(1) behavior of my residuals of my model. I noticed that there are multiple gls models in R. I am wondering if anyone has experience in choosing between gls models. For example, how should one decide whether to use lm.gls in MASS, or gls in nlme for correcting ar(1)? Does anyone have a preference? Any advice is appreciated! Thanks, -- Tom [[alternative HTML

On Thu, Apr 14, 2011 at 7:02 PM, <rcpp-devel-request at r-forge.wu-wien.ac.at> wrote: > I was able to write a very short C++ function using the Rcpp package > that provided about a 1000-fold increase in speed relative to the best > I could do in R. ?I don't have the script on this computer so I will > post it tomorrow when I am back on the computer at the office. > >

I am importing CSV data with thousands of rows, if any row contains an error from excel, the whole program crashes, so i need to delete all rows with the value of #VALUE!, all other values are non-numeric... I've tried a bunch of strategies, but nothing seems to work. Thanks ahead of time guys, Best, Cody -- View this message in context:

Hi, I've a vector like this: ------------------------------------------------------ > inc[,5] [1] NA NA NA NA NA NA NA [8] NA NA NA NA NA NA NA [15] NA NA NA NA NA NA NA [22] NA NA NA NA NA NA

Hi, I am currently using the following to formate numbers into percentages: x=0.00112 paste(round(x*100,2),"%",sep="") I am wondering if there is a built in R function that does the same. Does anyone know? Thanks, -- Tom [[alternative HTML version deleted]]

Dear folks-- Suppose I have an expression that evaluates to a string, and that that string, were it not a character vector, would be a symbol. I would like a function, call it doppel(), that will take that expression as an argument and produce something that functions exactly like the symbol would have if I typed it in the place of the function of the expression. It should go as far along the

Hi, all, When I schedule machine instructions in a VLIW way and packetize them, a problem is encountered, and I will show it use a simplified case as follows. ############ original instruction sequence ... insn1 ... jump LBB0_xx ... LBB0_xx: ... ############ expected instruction sequence after scheduling and packetizing insn1; jump LBB0_xx ... LBB0_xx: ... ############ generated instruction

Hi, I am trying to find a function in R that would calculate the critical value of t for a given probability and df. For example, if p=5% and df=20, then does R have a function to calculate the t value? I tried: > dt(0.05,df=20) [1] 0.3934718 That doesn't look right to me. Could someone tell me what I was missing? Thanks, -- Tom [[alternative HTML version deleted]]

It takes a lot of sweat to generate a composite plot with R ... sigh. I though I was almost done when I met the umpteenth hurdle. I cannot place a nice title on the 2nd plot (raw signal) on the layout. I do not have control on where either the "main" option of "plot" function, or "title", place the text string which keeps dysplaying chopped from above. I also tried

I have a list of data that is delimited by a / and, as long as there is an equal number of delimiters, I can parse the data and put it into a data frame: > t1<-c("a/a/a","b/bb/bbb","ccc/cc/c") > t2<-strsplit(t1,"/") > t3<-data.frame(t2) > t3 c..a....a....a.. c..b....bb....bbb.. c..ccc....cc....c.. 1 a

Hi guys, I'm running a KVM/libvirt host in a datacenter and got a fancy IPv4 subnet from my provider. I'm able to assign IPs from that subnet via dhcp to my VMs: host01 ~ # virsh net-dumpxml internet <network connections='3'> <name>internet</name> <uuid>37b888cc-510f-46f1-9246-346da96222ed</uuid> <forward dev='enp5s0f0'