search for: zack_holden

Dear list, I'm trying to download a text file directly from the internet using the RCurl package and the command getURL. Duncan Lang graciously helped me solve the first step in this problem using the following command: ################# txtfile <- getURL('ftp://ftp.wcc.nrcs.usda.gov/data/snow/snow_course/table/history/idaho/13e19.txt', ftp.use.epsv = FALSE) #################

Greetings R list, I am stuck on a simple syntax problem. I want to list all files in a directory, excluding files of a certain type. I have tried pattern matching as follows: a <- list.files(data, full.name = TRUE, pattern != ".xml") # exclude all .xml files The warning returns that my syntax is incorrect. I have read the regexpr help files and search old posts to no

Dear list, After searching many old posts, I can't find the solution to a simple problem. can someone tell me how to create a character string with multiple backslashes, as in: file_dir <- c("C:\files\data\") I need to create this string and then paste it to many files names for batch processing in another software program. R won't accept the backslash and removes

Dear list, I'm trying to write my first looping function in R. After many hours of searching help files and previous posts, I'm at wits end. Please forgive my programming ignorance...any help is greatly appreciated. I need to sort through a vector (x) and identify the point at which 2 successive values become smaller than the previous value. I've written a "while"

Dear list, I've recently installed R on a 64 bit machine with 8 GB of RAM. I set this computer up as a dual-boot system, with windows XP 64 and Ubuntu 7.10. I downloaded the Linux 64 bit version of R and installed it. I'm trying to run rather large Random forest models and was running into severe memory limitations with my old windows 32 bit machines. When I run Random Forest models

Dear List, I'm stuck on what seems like a simple indexing problem, I'd be very grateful to anyone willing to help me out. I queried a dataframe which returns a character vector called "plot". I have another dataframe from which I want to subset or select only those rows that match "plot". I've tried subset, and also the "which" command. plot

Dear list, I'm trying to compare two sets of variables using canonical analysis. My X variables include 3 climate indices, all continuous. My Y variables describe a set of 3 environmental moisture measurements. However, I would also like to include a class variable for habitat type. My colleaugue was able to do this in SAS, but we could not find a way to do it in R. Is anyone familiar

Dear list, I'm trying to query a string of numbers to identify where in the string the numbers stop increasing (where x[i] == x[i+1]). In example 1 below, I've adapted code from Jim Holt to do this. However, I run into situations where the condition is not met, as in example 2, where the number string is continuous. In this case, I need to specify an alternative outcome, where if in the

Dear list, Below I've written a clunky for loop that counts NA's in a row, replacing all with NA if there are more than 3 missing values, or keeping the values if 4 or more are present. This is sample code from a very large dataframe I'm trying to clean up. I know there are many simpler more elegant solutions to this little problem. Would someone be willing to show me how to

Dear list, I would like to plot 2 series of numbers with very different ranges/scales as lines on the same plot. I assumed this is commonly done and easy, but I have not found any help files (e.g. axis() or matplot() that show how. I've searched many old posts to no avail. I'll be very grateful for any suggestions on how this is done. Best, Zack

Dear list, I am trying to download a text file from an ftp site using download.file(). I used the following code: url <- "ftp://ftp.wcc.nrcs.usda.gov/data/snow/snow_course/table/history/idaho/13e19.txt" dest <- "c:/test/downloadtest.txt" download.file(url, dest) I get this error message, indicating that R is unable to open the connection: trying URL

Dear R wizards, I have a folder containing 1000 files. For each file, I need to extract the first row of each file, paste it to a new file, then write out that file. Then I need to repeat this operation for each additional row (row 2, then row 3, etc) for 23 rows in each file. I can do this with a for loop (as below). Is there a way to use some of the indexing power of R to get around this