使用R中的merge填充data.frame中的NA
我有一个数据框使用R中的merge填充data.frame中的NA,r,merge,R,Merge,我有一个数据框a缺少一些单元格的信息,我收集了缺少的数据,然后创建了另一个数据框b 通常我用以下代码填写缺失的数据: for (loop.b in (1:nrow(b))) {a[a[,"uid"]==b[loop.b,"uid"],"var1"] <- b[loop.b,"var1"] } (1:nrow(b))中的(loop.b)的 {a[a[,“uid”]==b[loop.b,“uid”],“var1”]我想你想要匹配,但很难猜测你的数据是什么样的 ## a's v
a
缺少一些单元格的信息,我收集了缺少的数据,然后创建了另一个数据框b
通常我用以下代码填写缺失的数据:
for (loop.b in (1:nrow(b)))
{a[a[,"uid"]==b[loop.b,"uid"],"var1"] <- b[loop.b,"var1"]
}
(1:nrow(b))中的(loop.b)的
{a[a[,“uid”]==b[loop.b,“uid”],“var1”]我想你想要匹配,但很难猜测你的数据是什么样的
## a's var1 has some missing values
a <- data.frame(var1 = c(1, NA, 4.5, NA, 6.5), uid = 5:1)
## b knows all about them
b <- data.frame(var1 = c(2.3, 8.9), uid = c(2, 4))
## find the indexes in a$uid that match b$uid
ind <- match(b$uid, a$uid)
## those indexes now can be filled directly with b$uid
a$var1[ind] <- b$var1
##a的var1缺少一些值
a假设以下两个数据帧与您描述的相似:
R> a <- data.frame(uid=1:10,var1=c(1:3,NA,5:7,NA,9:10))
R> a
uid var1
1 1 1
2 2 2
3 3 3
4 4 NA
5 5 5
6 6 6
7 7 7
8 8 NA
9 9 9
10 10 10
R> b <- data.frame(uid=c(8,4),var1=c(74,82))
R> b
uid var1
1 8 74
2 4 82
这项工作:
# matches of a$uid in b$uid, NA if not match
ind = match(a$uid, b$uid)
# 'ind' are the index in b and NA, we remove the latter
a[!is.na(ind),"var1"] = b[ind[!is.na(ind)],"var1"]
看看norm
软件包和prelim.norm
函数。Hmisc
有很好的插补功能,更不用说mi
…CRAN软件包列表是一个很好的起点。哦,顺便说一句,摆脱那个讨厌的循环…=)我可能很密集,你能帮我发布一个小的可复制的例子吗?
R> a
uid var1
1 1 1
2 2 2
3 3 3
4 4 82
5 5 5
6 6 6
7 7 7
8 8 74
9 9 9
10 10 10
# matches of a$uid in b$uid, NA if not match
ind = match(a$uid, b$uid)
# 'ind' are the index in b and NA, we remove the latter
a[!is.na(ind),"var1"] = b[ind[!is.na(ind)],"var1"]