FAQ 7.31 is probably the answer. If you want to try it, convert all your numerics that you want to merge on to character and round to the same value so you can "see" what is actually being matched. Comparing numerics for equality can present some challanges.
On Wed, Aug 26, 2009 at 9:22 PM, Mehdi Khan<mwk...@ucdavis.edu> wrote: > Note: even if I say by=c("LON", "LAT"), it doesn't work, suggesting that > number storage isn't the problem > > On Wed, Aug 26, 2009 at 6:19 PM, Mehdi Khan <mwk...@ucdavis.edu> wrote: > >> Hello everyone, >> >> Merging two dataframes should be easy. However when I try to merge, R >> doesn't recognize identical values, even if I am doing it by values that >> have no decimals. >> >> willclayong: >> vs30 LON LAT Net X wills.cat wills.vs30 clahan.cat clahanvs30 >> PolyID.wills PolyID.clahan tif.cat STA ELEVATION tif.vs30 >> 1 338.539 -3849590 4319319 <NA> 2 D 301 D >> 377 1958 1942 1 150 NA 519 >> 2 712.822 -3849590 4319319 <NA> 3 D 301 D >> 377 1958 1942 1 479 NA 519 >> 3 477.652 -3836584 4288164 <NA> 10 C 464 C >> 489 1194 9353 3 148 NA 547 >> 4 513.703 -3836575 4287739 <NA> 11 C 464 C >> 489 1194 9353 3 485 NA 547 >> 5 477.652 -3835886 4289120 <NA> 12 C 464 C >> 489 1194 9353 7 147 NA 388 >> >> wald: >> >> > wald_ol_sta[1:10,] >> X Wald.vs30 STA vs30 LON LAT >> 1 1 434.417 1502 274.500 -3077929 3759564 >> 2 2 378.049 NEE2 363.000 -3086165 3718184 >> 3 3 196.848 EMS 336.000 -3143337 3500449 >> 4 4 557.625 1498 659.600 -3103738 3871531 >> 5 5 263.878 1497 274.500 -3102944 3878068 >> 6 6 374.898 1499 274.500 -3109753 3858460 >> 7 7 150.000 230 274.500 -3154048 3482703 >> 8 8 248.342 1205 207.469 -3153294 3497116 >> 9 9 422.256 1495 338.600 -3097854 3990339 >> 10 10 322.540 1496 274.500 -3115300 3863905 >> >> willsclayongwald<-merge(wald_ol_sta, willsclayong, by=c("LON", "LAT", >> "STA", "vs30")) >> >> returns nothing... if I modify the previous script by adding "all=TRUE", I >> get this: >> >> >> lsclayongwald[1:10,] >> LON LAT STA vs30 X.x Wald.vs30 Net X.y wills.cat >> wills.vs30 clahan.cat clahanvs30 PolyID.wills PolyID.clahan tif.cat >> ELEVATION tif.vs30 >> 1 -3854850 4321856 478 513.703 1155 586.685 <NA> NA >> <NA> NA <NA> NA NA NA >> NA NA NA >> 2 -3849590 4319319 150 338.539 NA NA <NA> 2 D >> 301 D 377 1958 1942 1 NA >> 519 >> 3 -3849590 4319319 479 712.822 NA NA <NA> 3 D >> 301 D 377 1958 1942 1 NA >> 519 >> 4 -3849590 4319319 150 338.539 1152 336.794 <NA> NA >> <NA> NA <NA> NA NA NA >> NA NA NA >> >> >> rows 2 and 4 should have merged. Why didn't they? >> >> >> thanks! >> >> >> Mehdi Khan >> >> > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve? ______________________________________________ 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.