I want to calculate the mean of a list of named numbers. There are numeric(0) values that I first want to remove. Also, I would like to retrieve which elements of the list contain numeric(0) values.
我想计算一个命名数字列表的平均值。我首先要删除数字（0）值。此外，我想检索列表中的哪些元素包含数字（0）值。
Here is an example how the values could look like:
以下是值如何显示的示例：
>r["gg",]
$`01_1_er`
gg
0.5176445
$`02_1_er`
gg
0.4990959
$`03_1_er`
gg
0.5691489
$`22_1_er`
numeric(0)
$`23_1_er`
numeric(0)
$`25_1_er`
gg
0.386304
And here is the result of str:
这是str的结果：
> str(r["gg",])
List of 6
$ 01_1_er: Named num 0.518
..- attr(*, "names")= chr "gg"
$ 02_1_er: Named num 0.499
..- attr(*, "names")= chr "gg"
$ 03_1_er: Named num 0.569
..- attr(*, "names")= chr "gg"
$ 22_1_er: num(0)
$ 23_1_er: num(0)
$ 25_1_er: Named num 0.386
..- attr(*, "names")= chr "gg"
Can anyone help?
有人可以帮忙吗？
3 个解决方案
#1
19
## Example list
l <- list(n1=numeric(0), n2="foo", n3=numeric(0), n4=1:5)
## Filter out elements with length 0
l[lapply(l, length) > 0]
$n2
[1] "foo"
$n4
[1] 1 2 3 4 5
## Get names of elements with length 0
names(l)[lapply(l, length) == 0]
[1] "n1" "n3"
#2
2
Unlisting will pull out just the numeric entries in a single vector which you can call mean on, so try:
Unlisting将仅提取单个向量中的数字条目，您可以将其称为mean on，请尝试：
mean(unlist(r["gg",]))
#3
2
Another solution
另一解决方案
mean(unlist(Filter(is.numeric, l)))
#1
19
## Example list
l <- list(n1=numeric(0), n2="foo", n3=numeric(0), n4=1:5)
## Filter out elements with length 0
l[lapply(l, length) > 0]
$n2
[1] "foo"
$n4
[1] 1 2 3 4 5
## Get names of elements with length 0
names(l)[lapply(l, length) == 0]
[1] "n1" "n3"
#2
2
Unlisting will pull out just the numeric entries in a single vector which you can call mean on, so try:
Unlisting将仅提取单个向量中的数字条目，您可以将其称为mean on，请尝试：
mean(unlist(r["gg",]))
#3
2
Another solution
另一解决方案
mean(unlist(Filter(is.numeric, l)))