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
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
其他回答
我可能会这样做
length(which(numbers==x))
但实际上,更好的方法是
table(numbers)
也有计数(数字)从plyr包。在我看来,比餐桌方便多了。
numbers <- c(4,23,4,23,5,43,54,56,657,67,67,435 453,435,324,34,456,56,567,65,34,435)
> length(grep(435, numbers))
[1] 3
> length(which(435 == numbers))
[1] 3
> require(plyr)
> df = count(numbers)
> df[df$x == 435, ]
x freq
11 435 3
> sum(435 == numbers)
[1] 3
> sum(grepl(435, numbers))
[1] 3
> sum(435 == numbers)
[1] 3
> tabulate(numbers)[435]
[1] 3
> table(numbers)['435']
435
3
> length(subset(numbers, numbers=='435'))
[1] 3
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