R 不根据条件更新字段

Question

我有一个简单的 DF:

Dev_Func   
agn   
agn   
ttt   
ttt   
agn

我想做的就是如果该字段包含“agn”，请将其替换为“PE”

这是我编写的代码:

test = subset(Final.ds,Device_Function == "AGN" | Device_Function ==   
"TTT", select = c(Device_Function))
colnames(test) = c("Device_Function")
as.character(test)
test = within(test, Device_Function[Device_Function == 'AGN'] = 'PE')

但我不断收到此错误:

Warning message:
In `[<-.factor`(`*tmp*`, Device_Function == "AGN", value = "PE") :
invalid factor level, NA generated

它所做的就是用 NA 替换所有“AGN”值。请帮忙!

Answer 1

您可以使用gsub来做到这一点:

df$Dev_Func <- gsub("agn", "PE", df$Dev_Func)

df

#  Dev_Func
#1       PE
#2       PE
#3      ttt
#4      ttt
#5       PE

将 Dev_Func 作为一个因素的替代解决方案(如 akrun 提到的):

df$Dev_Func <- as.factor(gsub("agn", "PE", df$Dev_Func))

class(df$Dev_Func)

[1] "factor"