similar to: Looking for equivalent for "strstr"

It seems obvious to me that the empty string "" is length 0. cheers Worik [[alternative HTML version deleted]]

I have trouble with this: as.Date("Sep-1981", format="%b-%Y") Returns "NA" >From documentation for strftime '%b' Abbreviated month name in the current locale. (Also matches full name on input.) '%Y' Year with century. What am I doing wrong? cheers Worik [[alternative HTML version deleted]]

I have two pairs of related vectors x1,y1 and x2,y2 I wish to do a test for differences in means of x1 and y1, ditto x2 and y2. I am getting odd results. I am not sure I am using 'pt' properly... I have not included the raw vectors as they are long. I am interested if I am using R properly... > c(length(x1), length(y1), length(x2), length(y2)) [1] 3436 1619 2677 2378 First

I think I am whistling in the wind, but is there a modern symbolic debugger for R programmes? I am working through some one else's code, thousands of lines, that has the occasional bug in it, and a lot in my understanding of it. I cannot make setBreakpoint or findLineNum work. I get "No source refs found.". I am starting to loose my mind! A debugger where I could set

I am puzzled by the scope rules that apply with sapply. If I want to modify a vector with sapply I tried... N <- 10 vec <- vector(mode="numeric", length=N) test <- function(i){ vec[i] <- i } sapply(1:N, test) vec but it not work. How can this be done? Worik [[alternative HTML version deleted]]

Friends I clearly donot understand how sapply and vapply work. What I have is a function that returns a matrix with an indeterminate number of rows (some times zero) but a constant number of columns. I cannot reliably use an apply function to assemble the matrices into a matrix. I am not sure it is possible. I can demonstrate the core of my confusion with this simple code. A.f <-

Friends I am looking at Rcpp and I am a bit stuck on a simple matter. (I am calling R from c++, if there is a better way...) Given this simple example using the TTR package and the SMA function which returns a simple moving average.... Rcpp::NumericVector rv; for(int i = 0; i < 100; i++){ rv.push_back(rand()); } Rcpp::Environment TTR("package:TTR");

I have a large programme that after running half an hour or so fails with an error Error in x[value] <- NA : only 0's may be mixed with negative subscripts How can I find out where that error occurs? If I have to do a binary search using error messages it will take a long time! Is there some way I can generate a stack trace? cheers Worik [[alternative HTML version deleted]]

How can I increment the value of a Date class? I want to add a day, month or year to a date. cheers Worik [[alternative HTML version deleted]]

Friends I am trying to format a number to a string so 2189.745 goes to "2,189.35" and 309283.929 goes to "309,283.93" I have tried to use formatC(X, big.mark=",",drop0trailing=FALSE, format="f") but it does not get the number of decimals correct. Specifying digits does not work as that is significant digits. I could use a switch statement switching on

Is it possible to get a line number with an error report? I have a long script and an error: Error in `[.xts`(x, xsubset) : subscript out of bounds It would be very helpful, and save a lot of time, if there was some indication in the error message which line the error was. I can find it using binary search but that is a painful process. cheers Worik [[alternative HTML version deleted]]

Friends I have an xts that I wish to access. Browse[2]> DATA.ba[[p]]["2012-03-20 00:59:57","bid"] bid 2012-03-20 00:59:57 1.4993 So far so good. Now putting the index into a variable: Browse[2]> Time [1] "2012-03-20 00:59:57 NZDT" Browse[2]> DATA.ba[[p]][Time, "bid"] bid Where has it gone? Looking closer....

If I create a vector thusly > v1 <- runif(20, min=0, max=1) > v1 [1] 0.9754443 0.6306228 0.3238158 0.3175769 0.6791534 0.6956507 0.3840803 [8] 0.1421328 0.8592398 0.4388306 0.9472040 0.4727435 0.5645302 0.7391616 [15] 0.6116199 0.2727754 0.2657867 0.5261744 0.8764804 0.2032126 And I want to create a logical vector the same length that is true if v1<.3 or v1 > .7 how do I do it

Friends I am starting on a (section of the) project where I need to build a matrix with on the order of 5 million rows and 200 columns I am wondering if I can stay in R. I need to do rollapply type operations on the columns, including some that will be functions of (windows of) two columns. I have been looking at the ff and bigmemory packages but am not sure that they will do. Before I get

Is there a simple way to put a legend outside the plot area for a simple plot? I found... (at http://www.harding.edu/fmccown/R/) # Expand right side of clipping rect to make room for the legend *par(xpd=T, mar=par()$mar+c(0,0,0,4))* # Graph autos (transposing the matrix) using heat colors, # put 10% of the space between each bar, and make labels # smaller with horizontal y-axis labels

Friends I have a data frame, df that I want to extract some rows from Here is a sample of the data > head(df) TDate Expiry Underlie Strike CSettle PSettle Futures ExDate TTE 1 20080102 200801 200803 0.840 0.0000 0 0.9207 20080104 0.005479452 2 20080102 200801 200803 0.850 0.0000 0 0.9207 20080104 0.005479452 Rate Disc 1 0.0457 0.9997496 2 0.0457

I would like to know how many years (including partial years) are between two dates. So difftime("20/11/1962", "20/5/1964", units="years") would be about 1.5 But units of years are not available. cheers Worik [[alternative HTML version deleted]]

I am a bit worried I am reinventing the wheel. Isn't there a calendar system in R? I have written a function to add months to a date and return the number of days resulting. I am newish to R so I am hoping there is a package that can do this sort of date arithmetic for me... Worik DaysInMonths <- function(s,d){ ## Days in d months from s sdate <- MSTD(s) ## Get day, month

Given the following snippet.... m.nf.xts <- xts(rep(0, length(index(m.xts))), order.by=index(m.xts)) Does R know to cache the index(m.xts) or is it more efficient to say... m.i <- index(m.xts) m.nf.xts <- xts(rep(0, length(m.i)), order.by=index(m.i)) ? cheers Worik [[alternative HTML version deleted]]

I am sure this si a simple problem but the solution is evading me. I have a list of matrices all with the same number of columns but different number of rows. The first two columns label the row. The labels are allways the same for the same row numbers, just some matricies have more rows. For example using 3 column matrices... > q.1 <- function(r){return(cbind(seq(0, 10, by=1)[1:r],