对已过滤的列求和

Question

我试图总结一个过滤的列以计算出现的次数。如何求和字符数据类型。

bowler           dismissal_type
TS Mills         bowled
TS Mills         bowled
A Nehra          bowled
Pj cummins       bowled
TS Mills         bowled
A Nehra          bowled

我试图对dismissal_type求和，但抛出一个错误，提示不能对字符类型求和

bowled <- innings%>%
 filter(dismissal_type == "bowled")%>%
 group_by(bowler)%>%
 summarize_each(bowled = sum(dismissal_type == "bowled"))%>%
 top_n()

这似乎很简单，但无法完成。我要输出的是：

bowler           dismissal_type  n 
TS Mills         bowled          3
A Nehra          bowled          2
Pj cummins       bowled          1

Answer 1

你可以做

# Assuming the data frame is called bowler

# Define the subset
my_subset <- bowler$dismissal_type == "bowled"
# Count the occurrences of column bowler 
my_counts <- as.integer(ave(bowler$bowler, bowler$bowler, FUN = length))
# [1] 3 3 2 1 3 2
# Initialize the column n (needed in case the subset is strict)
bowler$n <- 1L  # or any other number, na_integer, etc.
bowler$n[my_subset] <- my_counts[my_subset]
#       bowler dismissal_type n
# 1   TS Mills         bowled 3
# 2   TS Mills         bowled 3
# 3    A Nehra         bowled 2
# 4 Pj cummins         bowled 1
# 5   TS Mills         bowled 3
# 6    A Nehra         bowled 2