Hi see in line
> -----Original Message----- > From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of Martin > Moller Skarbiniks Pedersen > Sent: Friday, September 8, 2017 10:49 AM > To: r-help@r-project.org > Subject: [R] Optimize code to read text-file with digits > > Hi, > > Every day I try to write some small R programs to improve my R-skills. > Yesterday I wrote a small program to read the digits from "A Million Random > Digits" from RAND. > My code works but it is very slow and I guess the code is not optimal. > > The digits.txt file downloaded from > https://www.rand.org/pubs/monograph_reports/MR1418.html > contains 20000 lines which looks like this: > 00000 10097 32533 76520 13586 34673 54876 80959 09117 39292 74945 > 00001 37542 04805 64894 74296 24805 24037 20636 10402 00822 91665 > 00002 08422 68953 19645 09303 23209 02560 15953 34764 35080 33606 > 00003 99019 02529 09376 70715 38311 31165 88676 74397 04436 27659 > 00004 12807 99970 80157 36147 64032 36653 98951 16877 12171 76833 > > My program which is slow looks like this: > > filename <- "digits.txt" > lines <- readLines(filename) why you do not read a file as a whole e.g. by lines<-read.table("digits.txt") After that you do not need for cycle (but maybe I misunderstand what you really want) remove first column lines <- lines[,-1] And now I am lost. Do you want each row convert into a numeric vector? It probably exceed the precision of biggest number allowed. Do you want to split each column to 5 numeric columns? you can use something like outer(lines[,1], 10^c(4:0), function(a, b) a %/% b %% 10) to split the first column. Or do you want one big numeric vector from all your numbers? here you need to read values as character variables lines<-read.table("digits.txt", colClasses="character") numbers<-as.numeric(unlist(strsplit(as.character(lines[1,]),""))) changes first row to numeric vector. Anyway, can you explain what is your final goal? Cheers Petr > > numbers <- vector('numeric') > for (i in 1:length(lines)) { > > # remove first column > lines[i] <- sub("[^ ]+ +","",lines[i]) > > # remove spaces > lines[i] <- gsub(" ","",lines[i]) > > # split the characters and convert them into numbers > numbers <- c(numbers,as.numeric(unlist(strsplit(lines[i],"")))) > } > > Thanks for any advice how this program can be improved. > > Regards > Martin M. S. Pedersen > > [[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. ________________________________ Tento e-mail a jakékoliv k němu připojené dokumenty jsou důvěrné a jsou určeny pouze jeho adresátům. 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