[R] Problem mit summaryBy: Group sums gives me incorrectly zero for one variable

Hi, first I want to thank all of you for the quick aid which is provided here on the list during all times. Thanks a lot for that! Then, I have a problem using summaryBy which most probably is a problem of wrong use by me or the like: I use this command: summaryBy(total+total.inf~gr, aE,

Re: [R] Problem mit summaryBy: Group sums gives me incorrectly zero for one variable

Just an additional note: It must be a problem with the variable names. If I change total.inf to for instance ttotal.inf then it works as expected. What is the rule here? I would like to avoid such problems in the future. Thanks, Werner Hi, first I want to thank all of you for the quick