similar to: Math problem with xts objects

Hi, I have a very large data set stored as an xts object. xts is very nice about showing row labels as "human readable" dates and times. I want the actual epoch values that are stored internally. The only way I can find to access them is one-at-a-time using the internal function: xcoredata() Calling this in an entire column, the "R" way doesn't work. It will only

Hello, I have a time series object (xts) that I iterate over in a loop. Works fine. My challenge is that I want to be able to reference other entries in the series by math. i.e. For today's observation, what were the last 5 observations? If indexed numerically, it is trivial, but I can figure out how to do this with dates. This is slightly more difficult as there may not be an

Hello, I noticed something odd when working with data frames and xts objects. If I read in a CSV file, R creates a nice data.frame. This works well. If I then convert to an XTS object, I see that all the values in the data are now quoted. My data is a mix of numeric and character. This is usually seen when converting a data.frame to a matrix, as R will treat all the data as the same class.

Hi, I have several data structures (xts structures). I then have a list of the names of those objects. I'd like to access the object by name. For example: foo1 <- as.xts(....) foo2 <- as.xts(...) foo3 <- as.xts(...) structs <- c("foo1", "foo2", "foo3") for (thisOne in structs){ print(thisOne$colA) } The above fails. Clearly I'm missing a

Hi, I have a rather large data frame (500 x 5000) that I want to convert to a proper xts object. I am able to properly generate an xts object with the correct time index. However, all of my numerical values are now strings. b <- as.xts(a[,2:dim(a)[2]], order.by=as.POSIXct(strptime(paste(a$Date), '%m/%d/%Y'))) My guess is that somewhere in the large data frame there are a few

Hi, I have a very large XTS object. It is about 600,000 entries over 1 year time. I would like to subset a specific piece, by "number of days" not a specific date. The way I do it now is awkward. Would love to find a way to do this easier to generate a new object just containing the days I want. --------------------------------------- dayEnds <- endpoints(dataset,

Hi to all, i'm new to R I have an xts object. Can i find: a) how many NA are in my object ? b) eventually where (in which line) they are Thank you

Hello, I'd like to convert the below time-series data with fft or wavelet related function and plot it. Could you let me know 1. How to convert xts data frame format to list format ? 2. How to plot fft or wavelet diagram ? Here is the data : &gt; class(zc) [1] "xts" "zoo" &gt; str(zc) An ‘xts’ object from (10/15/12 09:00:00) to (10/15/12 15:15:00)

Hello, I was just assigned to perform a cost effectiveness study in healthcare. We are studying the cost effectiveness of a proposed diagnostic vs. current screening procedures. One of the team members suggest a commercial software package called "TreeAge Pro". Looking at the description, it appears to be a nice GUI to some very simple models that could be easily constructed in R.

Hi, How can an xts object be subset using a date in a variable? E.g. in below, what is the right syntax for Q to get the same value as P? Obviously the syntax shown below doesnt work... V is an xts object. d = "2007-01-01" P <- V['2007-01-01/'] Q <- V['d/'] Thanks, J -- View this message in context:

Dear R-users I am new to R and struggling not to bother the list with silly questions. I read the documentation on xts and searched for some examples over the internet on how to use plot.xts. The xts object is as follows dataxts : An 'xts' object from 2010-06-27 to 2010-08-05 containing: Data: num [1:56161, 1:14] 74 74.2 74.2 74.1 73.9 ... Indexed by objects of

Hi R programmers, I have stumbled across what seems a very simple problem. My goal is to create a xts time series object which contains vectors as values. In other words, I try to create something like this: 2009-01-01 => c('aa', 'bb', 'dd') ... 2010-02-01 => c('mm') I have figured out parts of separately. Here's what works (new xts time-series with

Hello, I'm attempting to build a package using R 2.15.0 on OS X I am getting a generic failure when performing a cran type check on the package. Even with a very simple test package, it still fails int he same place. Example: In R: rm(list=ls()) foo <- function(x){print(x)} package.skeleton(name="foo") Then, at the command line: R CMD build foo R CMD check --as-cran

I have a bunch of data sets that were created for the libsvm tool. They are in "colon separated sparse format". i.e. 1 5:1 27:3 345:10 Is a row with the label of "1" and only has values in columns 5, 27, and 345. I want to read these into a data.frame in R. Is there a simple way to do this? -- Noah Silverman, M.S. UCLA Department of Statistics 8117 Math Sciences

hey I am trying to turn a dataframe into xts with the function: as.xts, but it returns the error: Error in as.POSIXlt.character(x, tz, ...) : character string is not in a standard unambiguous format could someone give me some pointers please the data is coming from a spreadsheet via the excel, and has 5 columns of data (date (with the date and time), open, high, low, close) (excel format) ela

I read enourmous comment about this questions stating that it was answered before.? I?have been looking for the answer for a week without luck !!!? I searched the archives the xts. vignitte , googled for an answer but couldn't find one so her it is: ? the Vignette states that xts "doesn't inforce the duplicate row requirement" but yet when I try to bring in tick stock data from

Hello, I need to calculate a moving average and an exponentially weighted moving average over a fairly large data set (500K rows). Doing this in a for loop works nicely, but is slow. ewma <- data$col[1] N <- dim(data)[1] for(i in 2:N){ data$ewma <- alpha * data$ewma[i-1] + (1-alpha) * data$value[i] } Since the moving average "accumulates" as we move through the data,

Hi, Looking at a large data set with many factors. I would like to expand each factor variable into multiple new variables for each level. (0,1) coding. My first though was just to code a big nasty loop, to take each level and cbind a column onto my data set. But, that seems painful. There must be a better way. Is there an "easy" way to do this in R? (Note, I don't want to

Hi, When using the glmnet() function of the package glmnet, A series of coefficients is returned for a list of descending lambda values. I am unable to locate anything in the documentation that explains HOW this choice of lambda series is made. (There is documentation about how to choose my own, but I want to understand how the authors are doing it) Any ideas? -- Noah Silverman UCLA

Hi, I want to keep a running file of some statistics generated by a running process. Occasionally the process will be restarted. On restart, I'd like to read the last line of the log file to set some variables to their last state, and then continue to append values to that same file. I can't seem to get the appending part to work. I can read values form the file, but then upon the