使用0或NAs替换所选列的负值(使用R)

对于示例数据 df ,我想替换第一列中的负值( x1 )与 0 和第三列( x3 )与 NA 按功能 replace_negatives 详情如下:

df  <- data.frame(x1 = -3:1,      
                    x2 = -1,
                    x3 = -2:2)
df 

出:

  x1 x2 x3
1 -3 -1 -2
2 -2 -1 -1
3 -1 -1  0
4  0 -1  1
5  1 -1  2

请注意,我不按列名编制索引,因为实际数据中有许多列,而且列名不是固定的。

replace_negatives <- function(data){
  df <<- data %>% 
    mutate(.[[1]] = if_else(.[[2]] < 0, 0, .[[1]])) %>%
    mutate(.[[3]] = if_else(.[[3]] < 0, NA, .[[3]])) 
  return(df)
}

lapply(df, replace_negatives)

但它引发了一个错误:

> replace_negatives <- function(data){
+   df <<- data %>% 
+     mutate(.[[1]] = if_else(.[[2]] < 0, 0, .[[1]])) %>%
Error: unexpected '=' in:
"  df <<- data %>% 
    mutate(.[[1]] ="
>     mutate(.[[3]] = if_else(.[[3]] < 0, NA, .[[3]])) 
Error: unexpected '=' in "    mutate(.[[3]] ="
>   return(df)
Error: no function to return from, jumping to top level
> }
Error: unexpected '}' in "}"

任何帮助都将受到感谢。

预期产出:

  x1 x2 x3
1  0 -1 NA
2  0 -1 NA
3  0 -1  0
4  0 -1  1
5  1 -1  2