similar to: How to subset based on column name that is a number ?

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, Does anyone know if the alternatives in the 'switch' function can be specified as strings containing spaces?  Neither of the two approaches below works. switch(expr, "Choice 1"="My first choice", "Choice 2"="My 2nd choice", "Choice 3"="My 3rd choice") x <- c("Choice 1", "Choice 2", "Choice

Hello, After reading help file, various threads on this board, and other online tutorials, I've attempted to use gsub (using Perl-like syntax) to change a currency string into something that can be converted to numeric type using only one regular expression.  Can anybody point out my error?  Note that >  x <- "\"$ 1,200,300,400.50\"" Tried the following in an

Hi, Would anyone have any idea as to why I would obtain completely different results when subsetting using the subset function vs bracket notation? I have a data frame with 65 variables and 4382 rows. When I use execute the following subset command I get the correct results (125 rows) > subset(df, Renewal==TRUE, 1:2)   However, I tried to obtain the same results with bracket notation as

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 <-

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

> -----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 <-

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")

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

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))

Hello, I'm wondering if the 'mosaic' plot of the vcd package (or any other function for that matter) can be used with a continuous variable that should be represented via various categorical variables.  All the documentation I've read lead me to believe that it only works with counts of categories. Alternatively, I've thought of first creating a contingency table where the

Hello, Is there a way to set the maximum width of character columns when printing a data frame? I've looked into print(), format(), and options() and have been unsuccessful. For example, I'd like to achieve the results below without having to modify the data itself. > x <- data.frame(c1=rnorm(5), c2="ABCDEFGHIJKLMNOPQRSTUVWXYZ") > x c1 c2 1

Dear R gurus, I have been struggling with this for a while and thought you might be able to give me some guidance. I have a data frame, on which I apply a row function. The result looks to me like a vector that retains the old row names. I then sort the vector and subsequently need to be able to identify the rank of certain values by searching for their row names. See this mock example: >

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 :