如何根据 R 中的 if 条件语句重新编码一组变量中的负值？

Question

这里是R新手。我目前正在尝试重新编码 R 中的一组变量，以便将其中的所有负值重新编码为正值。

请在下面找到模拟数据：

df <- data.frame(ID = c(1001, 1002, 1003, 1004, 1005, 1006, 1007, 1008, 1009, 1010, 1011),
                 measure1 = rnorm(11, mean = 0, sd = 1),
                 measure2 = rnorm(11, mean = 0, sd = 1),
                 measure3 = rnorm(11, mean = 0, sd = 1),
                 measure4 = rnorm(11, mean = 0, sd = 1))

这是我目前编写的函数：

df[2:5] <- sapply(df[2:5], function(x) {
  if(x<0) {
  return(x*-1)
}  else {
   return(x)
    }
  })

虽然我收到以下错误：

Warning messages:
1: In if (x < 0) { :
  the condition has length > 1 and only the first element will be used
2: In if (x < 0) { :
  the condition has length > 1 and only the first element will be used
3: In if (x < 0) { :
  the condition has length > 1 and only the first element will be used
4: In if (x < 0) { :
  the condition has length > 1 and only the first element will be used

关于如何使这项工作有任何想法吗？

谢谢！

Answer 1

您可以使用

df[, 2:5] <- abs(df[, 2:5])

如何根据 R 中的 if 条件语句重新编码一组变量中的负值？

How to recode negative values in a set of variables based on if conditional statement in R?

if-statement

r

function

conditional-statements

recode