52
votes
16
answers
3K
views
Changing column names of a data frame
I have a data frame called "newprice" (see below) and I want to change the column names in my program in R. &
62
votes
9
answers
1.6K
views
Check existence of directory and create if doesn't exist
I often find myself writing R scripts that generate a lot of output. I find it cleaner to put this output into
57
votes
30
answers
2.1K
views
How to find the statistical mode?
In R, mean() and median() are standard functions which do what you'd expect. mode() tells you the intern
57
votes
20
answers
1.6K
views
Counting the number of elements with the values of x in a vector
I have a vector of numbers: numbers <- c(4,23,4,23,5,43,54,56,657,67,67,435, 453,435,324,34,456,5
57
votes
8
answers
522
views
Cluster analysis in R: determine the optimal number of clusters
Being a newbie in R, I'm not very sure how to choose the best number of clusters to do a k-means analysis
61
votes
13
answers
903
views
How to find out which package version is loaded in R?
I am in a process of figuring out how to use my university cluster. It has 2 versions of R installed. System w
56
votes
28
answers
687
views
Tricks to manage the available memory in an R session
What tricks do people use to manage the available memory of an interactive R session? I use the functions bel
58
votes
11
answers
2.7K
views
Quickly reading very large tables as dataframes
I have very large tables (30 million rows) that I would like to load as a dataframes in R. read.table() has a
58
votes
17
answers
2.1K
views
Create an empty data.frame
I'm trying to initialize a data.frame without any rows. Basically, I want to specify the data types for e
63
votes
7
answers
2.7K
views
Run R script from command line
I have a file, called a.r, it has a chmod of 755, sayHello <- function(){ print('hello') } s
59
votes
7
answers
2.1K
views
46
votes
15
answers
706
views
Drop unused factor levels in a subsetted data frame
I have a data frame containing a factor. When I create a subset of this dataframe using subset or another inde
67
votes
24
answers
2.5K
views
Convert a list to a data frame
I have a nested list of data. Its length is 132 and each item is a list of length 20. Is there a quick way to
49
votes
12
answers
2.6K
views
The difference between bracket [ ] and double bracket [[ ]] for accessing the elements of a list or dataframe
R provides two different methods for accessing the elements of a list or data.frame: [] and [[]]. What is the
57
votes
12
answers
2.6K
views
How to unload a package without restarting R
I'd like to unload a package without having to restart R (mostly because restarting R as I try out differ
57
votes
8
answers
2.2K
views
What is the difference between require() and library()?
What is the difference between require() and library()?
53
votes
18
answers
821
views
How should I deal with "package 'xxx' is not available (for R version x.y.z)" warning?
I tried to install a package, using install.packages("foobarbaz") but received the warning Warning message
44
votes
11
answers
1K
views
How can I view the source code for a function?
I want to look at the source code for a function to see how it works. I know I can print a function by typing
57
votes
16
answers
2.3K
views
Plot two graphs in same plot in R
I would like to plot y1 and y2 in the same plot. x <- seq(-2, 2, 0.05) y1 <- pnorm(x) y2 <- pnorm(x
61
votes
11
answers
1.1K
views
How to convert a factor to integer umeric without loss of information?
When I convert a factor to a numeric or integer, I get the underlying level codes, not the values as numbers.
