You need Yut_are <- subset (Yut, Mark=="Arecaceae", select=c(X, Y, Mark))
for equality test (two "==") On Sat, Nov 29, 2008 at 5:22 AM, Ophelia Wang <[EMAIL PROTECTED]> wrote: > Hi all, > > I thought this should be very simple, but I'm not sure where the > problem is. I have a .txt data file that contains X and Y coordinates > of trees and their family names: > > "X" "Y" "Mark" > 0 28 "Sapotaceae" > 1 30 "Meliaceae" > 1 40 "Meliaceae" > 1 60 "Mimosaceae" > 1 76 "Olacaceae" > 1.5 73 "Myristicaceae" > 2 34 "Euphorbiaceae" > 2 62 "Olacaceae" > 2 86 "Mimosaceae" > 2.5 36 "Arecaceae" > 3 22 "Nyctaginaceae" > 3 25 "Moraceae" > 3 38 "Rubiaceae" > 3 47 "Desconocido " > 3 99 "Mimosaceae" > 3.5 24 "Anacardiaceae" > 3.5 57 "Sapotaceae" > 4 1 "Lecythidaceae" > > Now I just want to work on one family for various spatial analyses in > ads and spatstats, so I wrote: > > Yut <-read.delim( > "C:/dissertation/data2006/Parcela_1-3/Yutsun_tree.txt", header = TRUE, > sep = "\t", quote="\"", dec=".", fill = TRUE ) > > Yut_are <- subset (Yut, Mark="Arecaceae", select=c(X, Y, Mark)) > > However, the summary of Yut_are still contains trees of other families: > > X Y Mark > Min. : 0.00 Min. : 0.00 Myristicaceae: 65 > 1st Qu.: 24.00 1st Qu.:24.00 Lecythidaceae: 60 > Median : 46.00 Median :51.00 Sapotaceae : 51 > Mean : 48.07 Mean :49.72 Moraceae : 45 > 3rd Qu.: 72.50 3rd Qu.:75.50 Arecaceae : 41 > Max. :100.00 Max. :99.00 Mimosaceae : 34 > (Other) :313 > > Please tell me how do I subset a dataset like this to extract trees > from only one or a few families? Thanks a lot! > > Ophelia > > -- > Yung-Ho (Ophelia) Wang > Doctoral Candidate > Department of Geography and the Environment > University of Texas > +1-512-232-1597 > [EMAIL PROTECTED] > > ______________________________________________ > 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.
