This will work if you are using matrices (if you have data frames, convert them to matrix): > table1 q1 q3 q4 q8 q9 A 5 2 0 1 3 B 2 0 2 4 4 > table2 q1 q2 q3 q4 q5 q6 q7 q8 q9 C 10 7 4 2 6 9 3 1 2 > index <- match(colnames(table2), colnames(table1), nomatch=0) > t(t(table1[,index]) / table2[index != 0, drop=FALSE]) q1 q3 q4 q8 q9 A 0.5 0.5 0 1 1.5 B 0.2 0.0 1 4 2.0
On 11/12/05, Claus Atzenbeck <[EMAIL PROTECTED]> wrote: > > Hello, > > I have a table (1) of the form > > q1 q3 q4 q8 q9 > A 5 2 0 1 3 > B 2 0 2 4 4 > > I have another table (2): > > q1 q2 q3 q4 q5 q6 q7 q8 q9 > C 10 7 4 2 6 9 3 1 2 > > I would like to divide the numbers in table (1) by the number of the > appropriate column in table (2): > > q1 q3 q4 q8 q9 > A 5/10 2/4 0/2 1/1 3/2 > B 2/10 0/4 2/2 4/1 4/2 > > The result would look lie this: > > q1 q3 q4 q8 q9 > A 0.5 0.5 0 1 1.5 > B 0.2 0 1 4 2 > > BACKGROUND: I have a data frame with measured times for answering > questions. I want to know how many PERCENT of the answers are wrong, > caused by reason A or B. > > This gives me the subset of false answers. The table looks like table (1): > > fail <- subset(questions, type=="wrong") > fail$qid <- factor(fail$qid) > failtab <- table(fail$failtype, fail$qid) > > The following gives me information about how often a specific question > was asked. This is similar to table (2) above. > > count <- table(questions$failtype, questions$qid) > count <- colSums(count) > > One solution would be to delete the line that calls factor(...) on the > subset and calculate failtab/count. However, then I have the problem > that I have to get rid of all columns of the table that have '0' in all > rows. > > Thanks for any hint. > Claus > > ______________________________________________ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html > -- Jim Holtman Cincinnati, OH +1 513 247 0281 What the problem you are trying to solve? [[alternative HTML version deleted]] ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
