相关疑难解决方法(0)

假设我有两列数据.第一个包含诸如"First","Second","Third"等类别.第二个包含代表我看到"First"的次数的数字.

例如:

Category     Frequency
First        10
First        15
First        5
Second       2
Third        14
Third        20
Second       3

我想按类别对数据进行排序并对频率求和:

Category     Frequency
First        30
Second       5
Third        34

我怎么会在R？

我有一个数据框

ID <- c("A","A","A","A","B","B","B","B") 
Type <- c(45,45,46,46,45,45,46,46)
Point_A <- c(10,NA,30,40,NA,80,NA,100) 
Point_B <- c(NA,32,43,NA,65,11,NA,53)
df <- data.frame(ID,Type,Point_A,Point_B)

    ID  Type    Point_A Point_B
1   A   45        10    NA
2   A   45        NA    32
3   A   46        30    43
4   A   46        40    NA
5   B   45        NA    65
6   B   45        80    11
7   B   46        NA    NA
8   B   46       100    53

虽然我从这篇文章中了解到,但我可以用ID和一列来汇总数据.

我目前正在使用sqldf按ID和类型对行和组进行求和.虽然这对我来说很重要,但它在更大的数据集上却非常缓慢.

    df1 <- sqldf("SELECT ID, Type, Sum(Point_A) as Point_A, Sum(Point_A) as Point_A 
                  FROM df 
                  GROUP BY ID, …