My general approach is to import data without letting the import convert to factors. Then I explicitly create my factors with the levels I want them to have, with explicit vectors specified for the levels. Fixing this after the analysis is possible but a headache.
On March 28, 2020 5:46:25 PM PDT, Rolf Turner <r.tur...@auckland.ac.nz> wrote: > >I have an application in which I want to plot points with different >colours and symbols to distinguish (three) types of point. I thought I > >had it figured out, mostly by a trial-and-error approach and by >simple-mindedly following instructions from others, without (sad to >say) >really understanding what I was doing. > >I have now encountered an example where my syntax screws up, and I >can't >see how to fix it in a coherent and generally applicable way. The >problem arises if the data column (factor) specifying the point types >is >missing one level. When this happens, the types get out of synch. > >I have attached a source-able file "demo.txt" and the two data sets >upon >which it depends as "data1.txt" and "data2.txt" (dput() format). > >The result from using the data from "data1.txt" (plotObj1) demonstrates > >the problem, i.e. the unwanted phenomenon. The result from using the >data from "data2.txt" (plotObj2) is "as it should be". > >In the data from data1.txt the "extremes" column, which specifies the >point type, is missing the level "0": > >> table(Dat1$extremes) >> >> 0 intermed 1 >> 0 39 43 > >As you will be able to see, the plot of these data has the "0" symbol >(a >triangle) where there should be an "intermed" symbol (a solid dot), and > >the "intermed" symbol where there should be a "1" symbol (an >upside-down >triangle). > >The data from data2.txt have an extremes column with all three levels >and the corresponding plot is as desired. > >I'm pretty sure that the solution to my problem is quite simple, but I >am too stupid to figure it out. Can anyone guide me in the right >direction? > >Thanks. > >cheers, > >Rolf Turner -- Sent from my phone. Please excuse my brevity. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
