similar to: Way to convert data frame to matrix

I have a text file that I have imported into R. It contains 3 columns and 316940 rows. The first column is vegetation plot ID, the second species names and the third is a cover value (numeric). I imported using the read.table function. My problem is this. I need to reformat the information as a matrix, with the first column becoming the row labels and the second the column labels and the cover

Hi. I searched the list and didn't found nothing similar to this. I simplified my example like below: #I need calculate correlation (for example) between 2 columns classified by a third one at a data.frame, like below: #number of rows nr = 10 #the third column is to enforce that I need correlation on two variables only dataf =

Dear all, In order to ease the transition from SPSS to R for some of my colleagues, I am trying to create a function which would show the variables and their labels (if those exist), using function "label" in package Hmisc. A toy example would be this: my.data <- data.frame(age=c(24,35,28), gender=c("Male", "Female", "Male")) require(Hmisc)

Hello, I have two problems in automating multiple glm(s) operations. The data file is tab delimited file with headers and two columns. like "ABC" "EFG" 1 2 2 3 3 4 dat <- read.table("FILENAME", header=TRUE, sep="\t", na.strings="NA", dec=".", strip.white=TRUE) dataf <- read.table("FILENAME", header=FALSE,

Hi, I have a global data-frame in my R script. At some point in my script, I want to update certain columns of this data-frame by calling in an update function. The function looks like this: # get events data. This populates a global event data frame in the R-script events <- getEvents(con, eventsFilePath) # events has columns eventid, timeStamp, isSynchronized, timeDiff; with millions of

Hello All, I am trying to write a function which would operate on columns of a dataframe specified in parameters passed to that function. f = function(dataf, col1 = "column1", col2 = "column2") { dataf$col1 = dataf$col2 # just as an example } The above, of course, does not work as intended. In some languages one can force evaluation of a variable, and then

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

Hello; I am having a problems with the interpretation of models using ordered or unordered predictors. I am running models in lmer but I will try to give a simplified example data set using lm. Both in the example and in my real data set I use a predictor variable referring to 3 consecutive days of an experiment. It is a factor, and I thought it would be more correct to consider it ordered. Below

Hi, 1.) The "median" function does not work well. Please refer to the data below (same data is attached as txt-delimited). This is what I try to do in R: median ( dataf [2:9] ) I get warning: "needs numeric data" 2.) BUT if apply the median to a single vector: median ( dataf [,2]] ) then it works: 3.) How come the "median"

> -----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, > > > >

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])

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 <-

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):

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")

In R, I'm imported a data frame of 2,321,123 by 4 called "dataF". I converted the data frame "dataF" to a matrix dataM <- as.matrix(dataF) Does R have an efficient routine to treat the special elements that contain "inf" in them. For example, can you separate the rows that have "inf" elements from the matrix into a separate matrix without

Hi, I like the formatting and the appearance of lattice plots. But I have not succeeded in gettting the right format in my plots with the lattice package in one of my applications. In?the code shown below, I start by constructing a general data frame and show my attempts with the lattice package commands. After that, I use the graphics package and show the kind of plot that I want to get. I would

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,

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,

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, >