对于数据框中的每一行，我想根据第三列中的值将值从一列复制到另一列。
我尝试使用组合for循环和if函数：
Accept: application/vnd.mycompany.tar+pdf这似乎有用（没有错误信息），但查看我的数据肯定有问题。
例如，第1行有 ## example
condition <- c("1","2","2","1","2","","3","3")
SZ01 <- c("1","1","1","1","1","","1","1")
SZ02 <- c("2","2","2","2","2","","2","2")
SZ03 <- c("3","3","3","3","3","","3","3")
df <- data.frame(cbind(condition,SZ01,SZ02,SZ03), stringsAsFactors = FALSE)
df$retribution <- NULL
df$special_prevention <- NULL
df$general_prevention <- NULL
for (i in 1:length(df$condition)){
if (df$condition[i] == 1){
df$retribution[i] <- df$SZ01[i]
df$special_prevention[i] <- df$SZ02[i]
df$general_prevention[i] <- df$SZ03[i]
}else if (df$condition[i] == 2) {
df$retribution[i] <- df$SZ02[i]
df$special_prevention[i] <- df$SZ03[i]
df$general_prevention[i] <- df$SZ01[i]
}else if (df$condition[i] == 3) {
df$retribution[i] <- df$SZ03[i]
df$special_prevention[i] <- df$SZ01[i]
df$general_prevention[i] <- df$SZ02[i]
} else {
df$retribution[i] <- "missing_condition"
df$special_prevention[i] <- "missing_condition"
df$general_prevention[i] <- "missing_condition"
}
}
。这意味着，此行condition == 1的值应与df$retribution的第1行中的值相同。
但事实并非如此。有没有人可以看到我犯的错误？
答案 0 :(得分：0)
尝试以下方法：
condition <- c("1","2","2","1","2","","3","3")
SZ01 <- c("1","1","1","1","1","","1","1")
SZ02 <- c("2","2","2","2","2","","2","2")
SZ03 <- c("3","3","3","3","3","","3","3")
df <- data.frame(cbind(condition,SZ01,SZ02,SZ03), stringsAsFactors = F)
df$retribution <- ifelse(df$condition == "1", df$SZ01,
ifelse(df$condition == "2", df$SZ02,
ifelse(df$condition == "3", df$SZ03, "missing")))
df$special_prevention <- ifelse(df$condition == "1", df$SZ02,
ifelse(df$condition == "2", df$SZ03,
ifelse(df$condition == "3", df$SZ01, "missing")))
df$general_prevention <- ifelse(df$condition == "1", df$SZ03,
ifelse(df$condition == "2", df$SZ01,
ifelse(df$condition == "3", df$SZ02, "missing"))))
输出：
df
condition SZ01 SZ02 SZ03 retribution special_prevention general_prevention
1 1 1 2 3 1 2 3
2 2 1 2 3 2 3 1
3 2 1 2 3 2 3 1
4 1 1 2 3 1 2 3
5 2 1 2 3 2 3 1
6 missing missing missing
7 3 1 2 3 3 1 2
8 3 1 2 3 3 1 2