data: > tmp1 Date HrMn Temp Q.4 1 19450101 0900 -37.0 1 2 19450101 1000 -35.9 2 3 19450101 1100 -35.9 3 4 19450101 1200 -36.4 4 5 19450101 1300 -36.4 5 6 19450101 1400 -36.4 6 7 19450101 1500 -36.4 7 8 19450101 1600 -37.5 9
Accidentally, I did this (I meant to write Q.4 instead of Q here) > tmp1$Q[tmp1$Q!="1" & tmp1$Q!= "5"]<-NA I would have expected it to tank, but still got a new field with the the values I wanted > tmp1 Date HrMn Temp Q.4 Q 1 19450101 0900 -37.0 1 1 2 19450101 1000 -35.9 2 <NA> 3 19450101 1100 -35.9 3 <NA> 4 19450101 1200 -36.4 4 <NA> 5 19450101 1300 -36.4 5 5 6 19450101 1400 -36.4 6 <NA> 7 19450101 1500 -36.4 7 <NA> 8 19450101 1600 -37.5 9 <NA> Can someone explain this? Peter > sessionInfo() R version 2.10.1 Patched (2010-03-16 r51294) i386-pc-mingw32 locale: [1] LC_COLLATE=English_United States.1252 LC_CTYPE=English_United States.1252 [3] LC_MONETARY=English_United States.1252 LC_NUMERIC=C [5] LC_TIME=English_United States.1252 attached base packages: [1] stats graphics grDevices utils datasets methods base other attached packages: [1] lattice_0.18-3 fortunes_1.3-7 zoo_1.6-2 loaded via a namespace (and not attached): [1] grid_2.10.1 tools_2.10.1 -- View this message in context: http://n4.nabble.com/strange-behavior-adds-new-field-by-non-existent-field-tp1603563p1603563.html Sent from the R help mailing list archive at Nabble.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.