similar to: Finding a vector position using names rather than values

Hi I want to extract columns from a data frame using a vector with the desired column names. This short example uses the select argument in the subset function to accomplish what I am trying to do. Is there a better solution? #names of desired columns colnames <- c("col1","col3") #my data data <-

Hi, I would like to extract columns from a dataframe using a vector of desired column names. The following working example uses the select argument in the subset function to accomplish what I am trying to do. Is there a better solution? Thanks. #my data data <- data.frame("col1"=c(1,2,3),"col2"=c("A","B","C"),"col3"=c(4,5,6))

> -----Original Message----- > From: William Dunlap > Sent: Tuesday, November 25, 2008 9:16 AM > To: 'johannes_graumann at web.de' > Subject: Re: [R] Efficient passing through big data.frame and > modifying select fields > > > Johannes Graumann johannes_graumann at web.de > > Tue Nov 25 15:16:01 CET 2008 > > > > Hi all, > > > >

Dear R friends: Can someone help me with the following problem? Many thanks in advance. # Problem Description: # I want to write functions which take a (character) vector of dataframe names as input argument. # For example, I want to extract the number of observations from a number of dataframes. # I tried the following: nobs.fun <- function (dframe.vec) { nobs.vec <-

Hello, I'm trying to figure out how to find the index of the second occurrence of "/" in a string (which happens to represent a date) within a data frame column. I've used the following code successfully to find the first instance of "/". dframe <- data.frame(date=c("5/14/2011", "4/7/2011")) dframe$x1 <- regexpr("/", dframe[, 1])

Hi, I have a data frame with column names "1", "2", "3", ... and I'd like to extract a subset based on the values in the first column. None of the methods I tried worked (below). x <- subset(dframe, 1 = = "My Text") x <- subset(dframe, "1" = = "My Text") x <- subset(dframe, names(dframe)[1] = = "My Text") Q

Dear alltogether, I experience very strange behavior of imputation of NA's with the NORM library. I use R 2.2.0, win32. The code is below and the same dataset was also tried with MICE and aregImpute() from HMISC _without_ any problem. The problem is as follows: (1) using the whole dataset results in very strange imputations - values far beyond the maximum of the respective column, >

Hi, I've looked all over for a solution to this, but haven't had much look in specifying what I want to do with appropriate search terms. Thus I'm turning to R-help. In the process of trying to write a simple function to rename individual column names in a data frame, I ran into the following problem: When I rename the columns within my function, I can't seem to get it to

Hi! I suspect there must be an easy way to access components of a data frame by name, i.e. the input should look like "name1 name2 name3 ..." and the output be a data frame of those components with the corresponding names. I ´ve been trying for hours, but only found the long way to do it (which is not feasible, since I have lots of components to select):

Hi, I really feel I've looked everywhere, although I know this can't be a hard problem. I'd like to be able to call the graph below as a function, but I can't get the function to recognize variables beyond 'dframe'. I've read through many papers on writing functions in R, but I can't get this to work. data <- data.frame('date' = as.Date(rep(c(15101,

Hi, It seems that there's a bug in summary, in the max. output... but max() alone works fine. > hw04.dframe$area ... [41] 1790 1380 1296 2745 798 2306 438649 1481 1559 2450 ... > summary(hw04.dframe) area Min. : 798 1st Qu.: 1349 Median : 1690 Mean : 6962 3rd Qu.: 2306 Max. :438600 ### should read 438649 or, to the point,

Hello, I created a table in MySQL with this command CREATE TABLE example (pk INT NOT NULL AUTO_INCREMENT,PRIMARY KEY(pk), id VARCHAR(30),col1 VARCHAR(30),col2 VARCHAR(30)) ### In R, I can connect to this table: library(DBI) library(RODBC) chan <- odbcConnect("MySQL51", uid="root", pwd="xxx") first <- sqlQuery(chan, "select * from example")

I frequently get data sets with cryptically-named variables. The datasets are more useful to me with informative variable names. I know that I can rename variables using the following command: dimname(dataset[[2]][index.of.variable.to.be.renamed]<-new.variable.name If I want to do this inside a function (say something I call RenameCol) what is the best way to communicate the

Hi, I am interested in implementing a special variant of balloonplot.  Let me explain with an example dataset from the reference manual : library(gplots) data(Titanic) dframe<-as.data.frame(Titanic) survived<-dframe[dframe$Survived=="Yes",] attach(survived) balloonplot(x=Class,y=list(Age,Sex),z=Freq,sort=TRUE,show.zeros=TRUE,cum.margins=FALSE,             main="BalloonPlot :

Hi Folks, Ran into something I'd really like to do in R simply/elegantly, but my R - coding skills seem surpassed. This is the thing. Imagine the following data: labs<-c("abcdef","abcgg","tgthefdk","tgtijuel","tgtnjmoi","gbnt","dlift") dat<-c(0.5,0.25,1,2,16,0.250,4) dframe<-data.frame(labs,dat) I would like to

Dear All, I am trying to build an error bar plot with ggplot2. However, even if the code seems to work, the plot is rather odd, with what seems to be a continuous line linking the different bars. I attach below the code I used, as well as the data. ================================================================ DFrame<-data.frame(x=1:10,y=0.5*(1:10),Upper=(1:10)+0.5, Lower=(1:10)-0.5) p

with pred.pca<-predict(splits[[i]]$pca,trainingData at samples)[,1:nPCs] dframe<-as.data.frame(cbind(pred.pca,class=isExplosive(trainingData,2))); results[[i]]$classifier<-ksvm(class~.,data=dframe,scaled=T,kernel="polydot",type="C-svc", C=C,kpar=list(degree=degree,scale=scale,offset=offset),prob.model=T) and a degree of 5 i get an error of 0 reported by the ksvm

Full_Name: Wolfgang Koller Version: 1.0.0 OS: linux Submission from: (NULL) (137.208.7.48) > data(UKLungDeaths) > ts.union(mdeaths, fdeaths,dframe=TRUE) Error in names<-.default(*tmp*, value = nmsers) : names attribute must be the same length as the vector > cbind(mdeaths, fdeaths,dframe=TRUE) Error in names<-.default(*tmp*, value = nmsers) : names attribute

Dear all, I'm attemping to find the overall range of values from column 5 of a series of data frames, on a per-row basis, and assign the results to a new object. At present, I'm only able to receive the overall range of all values, whereas I'm intending to get the results of the range for each corresponding row. This is what I have so far: for (i in seq(nrow(dframe[1]))) ???

Hello: I'm having trouble plotting an object of class "ts" that is in a data.frame. I can do it with(data.frame, plot(...)) but not with plot(..., data.frame); see the example below. This work around gets me past this problem. However, I thought the R Core team might want to know about this if they don't already. Thanks for all your work in making