Hello all, I am not sure whether it actually is a bug, but it is not the behaviour I would expect. Please consider this: >Sibships [1] Patient_2400 Patient_2400 Patient_345 Patient_345 Patient_8901 [6] Patient_8901 Patient_4008 Patient_4008 Patient_7991 Patient_7991 [11] Patient_8353 Patient_8353 Patient_1212 Patient_1212 Patient_2168 [16] Patient_2168 Patient_2760 Patient_2760 Patient_4726 Patient_4726 [21] Patient_6699 Patient_6699 Patient_7641 Patient_7641 Patient_8263 [26] Patient_8263 Patient_1389 Patient_1389 Patient_1618 Patient_1618 [31] Patient_2410 Patient_2410 Patient_2612 Patient_2612 Patient_2721 [36] Patient_2721 Patient_5053 Patient_5053 Patient_8458 Patient_8458 [41] Patient_211 Patient_211 Patient_9004 Patient_9004 Patient_3423 [46] Patient_3423 Patient_7413 Patient_7413 Patient_7815 Patient_7815 [51] Patient_9232 Patient_9232 Patient_2267 Patient_2267 Patient_468 [56] Patient_468 28 Levels: Patient_1212 Patient_1389 Patient_1618 Patient_211 ... Patient_9232 >Comparison_Indices [1] TRUE TRUE TRUE TRUE TRUE TRUE FALSE FALSE FALSE FALSE FALSE FALSE [13] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [25] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [37] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE TRUE TRUE [49] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE > Sibships[Comparison_Indices] [1] Patient_2400 Patient_2400 Patient_345 Patient_345 Patient_8901 [6] Patient_8901 Patient_7413 Patient_7413 28 Levels: Patient_1212 Patient_1389 Patient_1618 Patient_211 ... Patient_9232
The problem with this last command is that I would expect 4 levels (because only 8 "Comparison_Indices" are true, which is equal to 4 sibships. So: levels() does not take array indices into account or stated otherwise: if you use a subset in an array (vector), the levels() are not properly updated (to my opinion). What I additionally found is the following: > small_test <- factor(x=c("a", "b", "c")) > typeof(small_test) [1] "integer" The same happens to the Sibships that I defined as a factor? Why is it of type integer? This is the version() output: > version _ platform x86_64-unknown-linux-gnu arch x86_64 os linux-gnu system x86_64, linux-gnu status major 2 minor 6.1 year 2007 month 11 day 26 svn rev 43537 language R version.string R version 2.6.1 (2007-11-26) > So: should I submit a Bug report? Regards, Dr. Philip de Groot Wageningen University ______________________________________________ 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.