Hi, I have a table for an 1 week exam result for many classes in school, like this:
Day Class_ID Test Result 1 Monday 1 Paper Passed 2 Tuesday 1 Oral Passed 3 Friday 1 Paper Passed 4 Monday 3 Paper Passed 5 Sunday 3 Oral Passed 6 Monday 3 Paper Passed 6 Sunday 3 Paper Passed How can I sum the Word "Passed" from Result column ( for earch Class_ID and each Test), so i can get this following table: Class_ID Test Passed_Count 1 1 Paper 2 2 1 Oral 1 3 3 Oral 1 4 3 Paper 3 Passed_Count column is just the Value, how many people passed the exam. In the tabell, they are 2 people passed the paper test (Result=Passed). I hope someone can help me, Or maybe there is an example that i can see. Thank you in advance ______________________________________________ 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.