search for: ashenkin

Hello, I'm trying to extract the independent variables from a formula. The closest I've been able to come, aside from rolling my own, is the following: > a = y ~ b * x > attr(terms(formula(a)),"variables") The reason I'm doing this is that I'm building a grid of points that I use to construct a 3-d model prediction surface in rgl. If there are more than two

Hi folks, I'm trying to figure out how to get summarized data based on multiple columns. However, instead of giving summaries for every combination of categorical columns, I want it for each value of each categorical column regardless of the other columns. I could do this with three different commands, but i'm wondering if there's a more elegant way that I'm missing. Thanks!

Hi Folks, I'm trying to extract just the backreferences from a regex. > temp = "abcd1234abcd1234" > regmatches(temp, gregexpr("(?:abcd)(1234)", temp)) [[1]] [1] "abcd1234" "abcd1234" What I would like is: [1] "1234" "1234" Note: I know I can just match 1234 here, but the actual example is complicated enough that I have to

> is.na(strptime("5/2/1992", format="%m/%d/%Y")) [1] FALSE > is.na(strptime("5/3/1992", format="%m/%d/%Y")) [1] TRUE Any idea what's going on with this? Running strptime against all dates from around 1946, only 5/3/1992 was converted as "NA". Even stranger, it still seems to have a value associated with it (even though is.na thinks

Hello folks, I've been on a journey trying to figure out how to manage documents that are amenable to sharing and editing, but that contain dynamic content generated by R. I've come to the following solution: I use Sweave to generate labeled png & pdf figures, and I "Insert & Link" those figures as "Pictures" in a Word 2010 doc. Thus, when data or code

Hi Folks, I'm surprised, but I didn't find this question addressed anywhere. I'd like to generate a LaTeX caption with R code. I've tried the code below, but I get the following TeX error: ! Argument of \@caption has an extra }. <inserted text> \par l.21 } Any thoughts? Perhaps I'll have to write the "\caption{}" text with R? thanks!

Hello All, I'm getting my workflow switched over to Sweave, which is very cool. However, I collaborate with folks (as many of you must as well) who use Word to Track Changes amongst a group while crafting a paper. In the simplest case, there will just be two people (one Sweave user and one Word user) editing a paper. I'm wondering, how do Sweave users go about this? I could convert a

Hello, I need to take a dot product of each row of a dataframe and a vector. The number of columns will be dynamic. The way I've been doing it so far is contorted. Is there a better way? dotproduct <- function(dataf, v2) { apply(t(t(as.matrix(a)) * v2),1,sum) #contorted! } df = data.frame(a=c(1,2,3),b=c(4,5,6)) vec = c(4,5) dotproduct(df, vec) thanks,

Hi Folks, I'm trying to find a way to remove all terms in a formula that contain a particular interaction. For example, in the formula below, I'd like to remove all terms that contain the b:c interaction. > attributes(terms( ~ a*b*c*d))$term.labels [1] "a" "b" "c" "d" "a:b" "a:c" [7]

Hello all, What is your preferred method to export tables (from ftable()) to Word? Do you just export to a text file and then copy/paste? Or perhaps via HTML output? Thanks, Allie

Hello folks, I found a strangeness while experimenting with POSIXct vectors and lists. It seems that coerced NA's aren't "real" NAs, at least as considered by is.na()? > date_vec = c(as.POSIXct(now()), as.POSIXct(now()+1),NA,"b") > date_vec [1] "2012-08-22 15:00:46 COT" "2012-08-22 15:00:47 COT" NA [4] NA Warning message: In

Hi Folks, I'm trying to cut my data inside the summaryBy function. Perhaps formulas don't work that way? I'd like to avoid adding another column if possible, but if I have to, I have to. Any ideas? Thanks, Allie require(doBy) df = dataframe(a <- rnorm(100), b <-rnorm(100)) summaryBy(a ~ cut(b,c(-100,-1,1,100)), data=df) # preferred solution, but it throws an

Hello All, Searched around, haven't found a decent solution. I'd like to translate a vector of numbers to a matrix (or to a list of vectors) such that the vector values would serve as indicies of the 1's in an otherwise-zero-filled matrix (or list of vectors). For example: > a = c(1,3,3,4) # perform operation [,1] [,2] [,3] [,4] [1,] 1 0 0 0 [2,] 0 0 1

>>> Did you read this? >>> https://cran.r-project.org/doc/contrib/Leisch-CreatingPackages.pdf >>> >>> Maybe it could give you some insight in how to create package. >> >> That resource is ~9 years old. There are more modern treatments available. You >> can read mine at http://r-pkgs.had.co.nz. >> >> Hadley >> Thanks both.

Hello Folks, When I run the document below through sweave, rgui.exe/rsession.exe leaves a file handle open to the sweave-001.pdf graphic (as verified by process explorer). Pdflatex.exe then crashes (with a Permission Denied error) because the graphic file is locked. This only seems to happen when there is an error in the sweave document. When there are no errors, no file handles are left open.

Hello Folks, Is there any way to pass a list into a function such that the function will use the list as its arguments? I haven't been able to figure that out. The background: I'm trying to build a function that will apply another function multiple times, each time with a different set of specified arguments. I'm trying to figure out how to pass in a list of argument lists, then

Hi Folks, I'm running 32-bit R 2.14 in RStudio on my Win 7 x64 system with 8GB RAM. I'm getting memory problems as R wants to swallow more than the 4GB limit. I think I'm stuck at 4GB as I have to use 32-bit R for a number of packages (ODBC, etc). However, I doubt I really need to be using that much memory - I'm probably being very sloppy in my memory management, leaving lots

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 Folks, I've been bumping my head against the 4GB limit for 32-bit R. I can't go to 64-bit R due to package compatibility issues (ROBDC - possible but painful, xlsReadWrite - not possible, and others). I have a number of big dataframes whose columns all sorts of data types - factor, character, integer, etc. I run and save models that keep copies of the modeled data inside the model

Hello Folks, I have 5 columns for thousands of tree records that record whether that tree was alive or dead. I want to recode the columns such that the cell reads "found" when a live tree is first observed, "alive" for when a tree is found alive and is not just found, and "mort" when it was previously alive but is now dead. Given the following: > tree_live