Checking this with the bc R package (https://code.google.com/p/r-bc/), the Ryacas package (CRAN), the gmp package (CRAN) and the Windows 8.1 calculator all four give the same result:
> library(bc) > bc("168988580159 * 36662978") [1] "6195624596620653502" > library(Ryacas) > yacas("168988580159 * 36662978", retclass = "character") 6195624596620653502 > library(gmp) > as.bigz("168988580159") * as.bigz("36662978") Big Integer ('bigz') : [1] 6195624596620653502 On Sun, May 4, 2014 at 12:50 PM, Ted Harding <ted.hard...@wlandres.net> wrote: > On 04-May-2014 14:13:27 Jorge I Velez wrote: >> Try >> >> options(digits = 22) >> 168988580159 * 36662978 >># [1] 6195624596620653568 >> >> HTH, >> Jorge.- > > Err, not quite ... ! > I hitch my horses to my plough (with help from R): > > options(digits=22) > 168988580159*8 = 1351908641272 (copy down) > 168988580159*7 = 1182920061113 ( " " ) > 168988580159*9 = 1520897221431 ( " " ) > 168988580159*2 = 337977160318 ( " " ) > 168988580159*6 = 1013931480954 ( " " )^3 > 168988580159*3 = 506965740477 ( " " ) > > 1351908641272 > 11829200611130 > 152089722143100 > 337977160318000 > 10139314809540000 > 101393148095400000 > 1013931480954000000 > 5069657404770000000 > ====================== > 6195624596620653502 > [after adding up mentally] > > compared with Jorge's: > 6195624596620653568 > > ("02" vs "68" in the final two digits). > > Alternatively, if using a unixoid system with 'bc' present, > one can try interfacing R with 'bc'. 'bc' is an calculating > engine which works to arbitrary precision. > > There certainly used to be a utility in which R can evoke 'bc', > into which one can enter a 'bc' command and get the result > returned as a string, but I can't seem to find it on CRAN now. > In any case, the raw UNIX command line for this calculation > with 'bc' (with result) is: > > $ bc -l > [...] > 168988580159 * 36662978 > 6195624596620653502 > quit > > which agrees with my horse-drawn working. > > Best wishes to all, > Ted. > >> On Sun, May 4, 2014 at 10:44 PM, ARTENTOR Diego Tentor < >> diegotento...@gmail.com> wrote: >> >>> Trying algorithm for products with large numbers i encountered a difference >>> between result of 168988580159 * 36662978 in my algorithm and r product. >>> The Microsoft calculator confirm my number. >>> >>> Thanks. >>> -- >>> * Gráfica ARTENTOR * >>> >>> de Diego L. Tentor >>> Echagüe 558 >>> Tel.:0343 4310119 >>> Paraná - Entre Ríos > > ------------------------------------------------- > E-Mail: (Ted Harding) <ted.hard...@wlandres.net> > Date: 04-May-2014 Time: 17:50:54 > This message was sent by XFMail > > ______________________________________________ > R-help@r-project.org mailing list > 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. -- Statistics & Software Consulting GKX Group, GKX Associates Inc. tel: 1-877-GKX-GROUP email: ggrothendieck at gmail.com ______________________________________________ R-help@r-project.org mailing list 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.