I'm trying to filter row using the
count()
map %>% count(StudentID) = 3
StudentID StudentGender Grade TermName ScaleName TestRITScore
100 M 9 Fall 2010 Language Usage 217
100 M 10 2011-2012 Language Usage 220
100 M 9 Fall 2010 Reading 210
10016 M 6 Fall 2010 Language Usage 217
10016 M 6 Fall 2010 Mathematics 210
10020 F 7 Fall 2010 Language Usage 210
10020 F 7 Fall 2010 Mathematics 213
10022 F 8 Fall 2010 Language Usage 232
10022 F 9 2011-2012 Language Usage 240
10022 F 8 Fall 2010 Mathematics 242
count(df, StudentID)
I don't think count
is what you looking for. Try n()
instead:
df %>%
group_by(StudentID) %>%
filter(n() == 3)
# Source: local data frame [6 x 6]
# Groups: StudentID
#
# StudentID StudentGender Grade TermName ScaleName TestRITScore
# 1 100 M 9 Fall 2010 Language Usage 217
# 2 100 M 10 2011-2012 Language Usage 220
# 3 100 M 9 Fall 2010 Reading 210
# 4 10022 F 8 Fall 2010 Language Usage 232
# 5 10022 F 9 2011-2012 Language Usage 240
# 6 10022 F 8 Fall 2010 Mathematics 242