search for: lozone

...t;-airquality[1:10,] select.frame(aq,Ozone:Temp) subset.frame(aq,Ozone>20) modify.frame(aq,ratio=Ozone/Temp) Notice that in modify.frame(), any *new* variable must appear as a tag, not as the result of an assignment, i.e.: modify.frame(aq,Ozone<-log(Ozone)) works as expected modify.frame(aq,lOzone<-log(Ozone)) does not. This is mainly because it was tricky to figure out what part of a left hand side constitutes a new variable to be created (note that indexing could be involved). So assignments to non-existing variables just create them as local variables within the function. Making a vir...