值分配给从另一列基于条件列

Question

说我有一个这样的名单：

> desired <- c("10001", "10004") 

和样本数据帧是这样的：

> desired_sample_df <- data.frame(geo = rep("other", 30), zip = c(rep(10001:10010, 2), 10011:10020), cbsa = c(rep("NY", 20), rep("CA", 10))) 
> desired_sample_df 
    geo zip cbsa 
1 other 10001 NY 
2 other 10002 NY 
3 other 10003 NY 
4 other 10004 NY 
5 other 10005 NY 
6 other 10006 NY 
7 other 10007 NY 
8 other 10008 NY 
9 other 10009 NY 
10 other 10010 NY 
11 other 10001 NY 
12 other 10002 NY 
13 other 10003 NY 
14 other 10004 NY 
15 other 10005 NY 
16 other 10006 NY 
17 other 10007 NY 
18 other 10008 NY 
19 other 10009 NY 
20 other 10010 NY 
21 other 10011 CA 
22 other 10012 CA 
23 other 10013 CA 
24 other 10014 CA 
25 other 10015 CA 
26 other 10016 CA 
27 other 10017 CA 
28 other 10018 CA 
29 other 10019 CA 
30 other 10020 CA 

我想覆盖geo列的值只有在zip的值位于开头保存的desired列表中时才有值。

---

这是什么，我已经试过：

> desired_sample_df$geo[desired_sample_df$zip %in% desired] <- desired_sample_df$zip[which(desired_sample_df$zip %in% desired)] 
Warning message: 
In `[<-.factor`(`*tmp*`, desired_sample_df$zip %in% desired, value = c(NA, : 
    invalid factor level, NA generated 


> desired_sample_df$geo[desired_sample_df$zip %in% desired] <- desired_sample_df$zip 
Warning messages: 
1: In `[<-.factor`(`*tmp*`, desired_sample_df$zip %in% desired, value = c(NA, : 
    invalid factor level, NA generated 
2: In `[<-.factor`(`*tmp*`, desired_sample_df$zip %in% desired, value = c(NA, : 
    number of items to replace is not a multiple of replacement length 

Answer 1

像这样改变你想要的元素呢？

df$geo <- ifelse(df$zip %in% desired,df$zip,df$geo) 

在那里我打电话给你desired_sample_df，只是df。

Answer 2

其中的一个问题是，在dataframes字符串自动成为因素。试试这个：

desired <- c("10001", "10004") 
df <- data.frame(geo = rep("other", 30), zip = c(rep(10001:10010, 2), 10011:10020), cbsa = c(rep("NY", 20), rep("CA", 10)), stringsAsFactors=FALSE) 

idx <- df$zip %in% desired 

现在，您可以通过

df[idx, ]$geo <- df[idx, ]$zip