我有一个数字向量:
numbers <- c(4,23,4,23,5,43,54,56,657,67,67,435,
453,435,324,34,456,56,567,65,34,435)
我如何让R计算x值在向量中出现的次数?
我有一个数字向量:
numbers <- c(4,23,4,23,5,43,54,56,657,67,67,435,
453,435,324,34,456,56,567,65,34,435)
我如何让R计算x值在向量中出现的次数?
当前回答
也有计数(数字)从plyr包。在我看来,比餐桌方便多了。
其他回答
使用表,但不与名称比较:
numbers <- c(4,23,4,23,5,43,54,56,657,67,67,435)
x <- 67
numbertable <- table(numbers)
numbertable[as.character(x)]
#67
# 2
当您多次使用不同元素的计数时,Table非常有用。如果你只需要一个计数,使用sum(numbers == x)
您可以在下面一行中将数字更改为您希望的任何数字
length(which(numbers == 4))
一个选项是使用vctrs库中的vec_count()函数:
vec_count(numbers)
key count
1 435 3
2 67 2
3 4 2
4 34 2
5 56 2
6 23 2
7 456 1
8 43 1
9 453 1
10 5 1
11 657 1
12 324 1
13 54 1
14 567 1
15 65 1
默认顺序将最常用的值放在顶部。如果根据键进行排序(类似table()的输出):
vec_count(numbers, sort = "key")
key count
1 4 2
2 5 1
3 23 2
4 34 2
5 43 1
6 54 1
7 56 2
8 65 1
9 67 2
10 324 1
11 435 3
12 453 1
13 456 1
14 567 1
15 657 1
计算特定元素有不同的方法
library(plyr)
numbers =c(4,23,4,23,5,43,54,56,657,67,67,435,453,435,7,65,34,435)
print(length(which(numbers==435)))
#Sum counts number of TRUE's in a vector
print(sum(numbers==435))
print(sum(c(TRUE, FALSE, TRUE)))
#count is present in plyr library
#o/p of count is a DataFrame, freq is 1 of the columns of data frame
print(count(numbers[numbers==435]))
print(count(numbers[numbers==435])[['freq']])
你可以创建一个函数来得到结果。
# your list
numbers <- c(4,23,4,23,5,43,54,56,657,67,67,435,
453,435,324,34,456,56,567,65,34,435)
function1<-function(x){
if(x==value){return(1)}else{ return(0) }
}
# set your value here
value<-4
# make a vector which return 1 if it equal to your value, 0 else
vector<-sapply(numbers,function(x) function1(x))
sum(vector)
结果:2