You should probably pick a forum — here or SO : http://stackoverflow.com/questions/39547398/faster-reading-of-binary-files-in-r : - vs cross-post to all of them.
On Sat, Sep 17, 2016 at 11:04 AM, Ismail SEZEN <sezenism...@gmail.com> wrote: > I noticed same issue but didnt care much :) > > On Sat, Sep 17, 2016, 18:01 jim holtman <jholt...@gmail.com> wrote: > > > Your example was not reproducible. Also how do you "break" out of the > > "while" loop? > > > > > > Jim Holtman > > Data Munger Guru > > > > What is the problem that you are trying to solve? > > Tell me what you want to do, not how you want to do it. > > > > On Sat, Sep 17, 2016 at 8:05 AM, Philippe de Rochambeau <phi...@free.fr> > > wrote: > > > > > Hello, > > > the following function, which stores numeric values extracted from a > > > binary file, into an R matrix, is very slow, especially when the said > > file > > > is several MB in size. > > > Should I rewrite the function in inline C or in C/C++ using Rcpp? If > the > > > latter case is true, how do you « readBin » in Rcpp (I’m a total Rcpp > > > newbie)? > > > Many thanks. > > > Best regards, > > > phiroc > > > > > > > > > ------------- > > > > > > # inputPath is something like http://myintranet/getData? > > > pathToFile=/usr/lib/xxx/yyy/data.bin <http://myintranet/getData? > > > pathToFile=/usr/lib/xxx/yyy/data.bin> > > > > > > PLTreader <- function(inputPath){ > > > URL <- file(inputPath, "rb") > > > PLT <- matrix(nrow=0, ncol=6) > > > compteurDePrints = 0 > > > compteurDeLignes <- 0 > > > maxiPrints = 5 > > > displayData <- FALSE > > > while (TRUE) { > > > periodIndex <- readBin(URL, integer(), size=4, n=1, > > > endian="little") # int (4 bytes) > > > eventId <- readBin(URL, integer(), size=4, n=1, > > > endian="little") # int (4 bytes) > > > dword1 <- readBin(URL, integer(), size=4, signed=FALSE, > > > n=1, endian="little") # int > > > dword2 <- readBin(URL, integer(), size=4, signed=FALSE, > > > n=1, endian="little") # int > > > if (dword1 < 0) { > > > dword1 = dword1 + 2^32-1; > > > } > > > eventDate = (dword2*2^32 + dword1)/1000 > > > repNum <- readBin(URL, integer(), size=2, n=1, > > > endian="little") # short (2 bytes) > > > exp <- readBin(URL, numeric(), size=4, n=1, > > > endian="little") # float (4 bytes, strangely enough, would expect 8) > > > loss <- readBin(URL, numeric(), size=4, n=1, > > > endian="little") # float (4 bytes) > > > PLT <- rbind(PLT, c(periodIndex, eventId, eventDate, > > > repNum, exp, loss)) > > > } # end while > > > return(PLT) > > > close(URL) > > > } > > > > > > ---------------- > > > [[alternative HTML version deleted]] > > > > > > ______________________________________________ > > > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > > > https://stat.ethz.ch/mailman/listinfo/r-help > > > PLEASE do read the posting guide http://www.R-project.org/ > > > posting-guide.html > > > and provide commented, minimal, self-contained, reproducible code. > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide > > http://www.R-project.org/posting-guide.html > > and provide commented, minimal, self-contained, reproducible code. > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/ > posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
