Displaying 20 results from an estimated 8000 matches similar to: "strsplit and sapply"
2011 May 26
4
Applying "toupper" to only portions of text strings
Colleagues
Assume that I have a vector containing some text strings, some of which contain a particular character. I could like to apply "toupper" to the text before the character. For example (in this case, "|" is the particular character):
ORIGINAL:
TEXT <- c("aaaa", "bbb|cc", "|ddd")
AFTER APPLICATION OF toupper:
TEXT <-
2005 Jul 22
3
Question regarding subsetting
I run R 2.1.1 in a Linux environment (RedHat 9) although my question
is not platform-specific.
Consider the following:
> A <- c("Prefix-aaa", "Prefix-bbb", "Prefix-ccc")
> B <- strsplit(A, "-")
> B
[[1]]
[1] "Prefix" "aaa"
[[2]]
[1] "Prefix" "bbb"
[[3]]
[1] "Prefix" "ccc"
How
2007 Aug 14
1
{grid} plain units with non NULL data arguments
In help(unit) I read:
The 'data' argument must be a list when the 'unit.length()'
is greater than 1. For example, 'unit(rep(1, 3), c("npc",
"strwidth", "inches"), data=list(NULL, "my string", NULL))'.
In the newest R-versions it is not anymore allowed to let strings
in the data-argument for plain units, otherwise one
2008 May 10
2
Random number generation
Colleagues,
I have encountered behavior of random number generation that eludes me.
I generate a random integer in a particular range using the following
code:
sample(1000:9999, size=1)
This code exists within a script that starts with the command:
remove(list=ls())
Each time that I run the script, it yields the same random number:
6420.
I thought that the problem might result from
2005 Oct 18
6
Subsetting a list
Colleagues,
I have created a list in the following manner:
TEST <- list(c("A1", "A2"), c("B1", "B2"), c("C1", "C2"))
I now want to delete one element from the list, e.g., the third. The
command
TEST[[3]]
yields (as expected):
[1] "C1" "C2"
The command
TEST[[-3]]
yields:
Error:
2009 Sep 29
3
Deleting a column in a dataframe by name
Colleagues,
Hopefully a simple problem: I want to delete a column with a known
name from a dataframe. I could write:
FRAME <- FRAME[, names(FRAME) != NAMETODELETE]
or
FRAME <- FRAME[, !names(FRAME) %in% c(NAME1, NAME2, ETC)]
Is there some simpler means to accomplish this?
Dennis
Dennis Fisher MD
P < (The "P Less Than" Company)
Phone: 1-866-PLessThan (1-866-753-7784)
2008 Dec 09
2
Replacing tabs with appropriate number of spaces
Colleagues,
Platform: OS X (but issue applies to all platforms)
Version: 2.8.0
I have a mixture of text and data that I am outputting via R to a pdf
document (using a fixed-width font). The text contains tabs that
align columns properly with a fixed-width font in a terminal window.
However, when the PDF document is created, the concept of a tab is not
invoked properly and columns do
2007 Sep 04
2
Recursive concatenation
Colleagues,
I want to create the following array:
"A1", "A2", "A3", "B1", "B2", "B3", "C1", "C2", "C3"
I recall that there is a trick using "c" or "paste" permitting me to
form all combinations of c("A", "B", "C") and 1:3. But, I can't
recall the
2007 Aug 03
3
Sourcing commands but delaying their execution
Colleagues:
I have encountered the following situation:
SERIES OF COMMANDS
source("File1")
MORE COMMANDS
source("File2")
Optimally, I would like File1 and File2 to be merged into a single
file (FileMerged). However, if I wrote the following:
SERIES OF COMMANDS
source("FileMerged")
MORE COMMANDS
I encounter an error: the File2 portion of FileMerged
2008 Dec 15
3
opening a PDF document
Colleagues,
I am interesting in opening a PDF document via the command line from
both Windows, OS X, and Linux ( R version 2.8.0). I found a command
openPDF in Biobase. However, I would rather execute the command
myself. For example, in OS X:
> system("open filename.pdf")
is successful.
Is there a comparable command line command for Windows or Linux?
Dennis
Dennis Fisher
2006 Oct 21
2
Filling in a series
Colleagues
After reading in some clinical data, I discovered that the subject ID
column contains entries only for the first record for each
individual; subsequent rows are recorded as NA. For example:
> 1
> NA
> NA
> NA
> NA
> 2
> NA
> NA
> NA
> NA
> 3
> NA
> NA
> ...
I can think of various approaches to replace the NA values with
appropriate
2009 Jan 30
3
identifying what labels have been created in a plot
Colleagues
R 2.8.0; OS X, Vista, Ubuntu Linux
In some instances, when I create a graphic using plot(XVAR, YVAR), it
would be valuable to know the values that R will display on the y-axis
(e.g., if the range of data is 0-70, it might display 0, 10, 30, 50,
70). Is there a simple means to access these values?
Also, in some instances, additional ticks appear between the displayed
values
2009 Sep 23
2
Updating R for Linux
Colleagues,
Please forgive my ignorance of this topic. I am experienced with the
installation/use of R in OSX and Windows, much less so with Linux.
I just created a virtual machine of Ubuntu 9.0.4. Using the Synaptic
Package Manager, I installed R 2.8.1. I would like to obtain 2.9.x
and I am having trouble doing so using the tools available within
Ubuntu.
I tried
apt-get install
2008 Nov 07
2
Unexpected behavior of clocktime related to daylight savings time
Colleagues,
I submitted this several days ago and no one responded, so I am trying
again, trying a different subject line:
I just encountered some unexpected behavior of difftime in
relationship to the change from daylight savings to standard time.
My understanding is that DST and ST take effect at 2AM. However, the
results below suggests that R (version 2.8.0 in OS X) implements the
2010 Feb 12
1
Identifying special characters in a text file
Colleagues
R 2.10.1 on a Mac
I read in textfiles using readLines, then I process those files, then I use R to execute another program. Occasionally those files contain characters other than letter / numbers / routine punctuation marks. For example, a bullet (option-8 on a Mac) triggers the problem.
Although R can read and process those characters, the other program cannot so I would like to
2005 Jan 17
2
Question about time series
I have data in the following format:
> DATE
[1] "01/13/2004"
In order to find the difference between two data points, I presently
use brute force to calculate the day of the year:
> strptime(DATE, format="%m/%d/%Y")$yday
[1] 12
Although this works, it may not be robust over different years. I
assume that R is sufficiently clever that a much simpler approach
2007 Sep 17
3
Sourcing encrypted files
Colleagues,
I have an unusual problem; I am wondering whether anyone has dealt
with it and found a solution.
I have a script that needs to be encrypted. R will then be run on
the script. There are various means to decrypt the file, some of
which leave the decrypted code on the hard drive for an excessive
period.
One means that I have considered to deal with this is the following
2012 Oct 18
4
speeding read.table
R 2.15.1
OS X
Colleagues,
I am reading a 1 GB file into R using read.table. The file consists of 100 tables, each of which is headed by two lines of characters.
The first of these lines is:
TABLE NO. 1
The second is a list of column headers.
For example:
TABLE NO. 1
COL1 COL2 COL3 COL4 COL5 COL6 COL7 COL8 COL9 COL10
2008 Oct 12
2
proper use of textConnection
Colleagues,
Using R2.7.0 in OS X, I am having trouble understanding the command
textConnection. My situation is as follows:
1. I am trying to read a lengthy file (45000 lines) that has headers
~ every 1000 lines. read.table (or its variants) fail because of the
recurrent headers.
2. My present approach is the following:
a. use readLines to read the file, save as an array
b. use grep
2005 Dec 04
2
tiff graphics
Colleagues
I frequently insert PDF graphics created with R into Word (Office
2004 for Mac) documents. The documents are created on either a
Linux machine (RedHat 9) or a Mac (Tiger). I am using R 2.2.0.
These pdf graphics often lose a great deal of resolution after
insertion into Word compared to their high quality when printed as
PDF documents. I recently learned that converting the