当R中只有数字时，删除空格并将值转换为数字

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我一直在网上寻找这个问题

与通常的发现不同的是，我有一些列，其中有数字和其他不同于纯数字的值。

例如说：

df <- data.frame('Col1' = c('421', ' 0.52', '-0.88 ', '1.2 (ref)', ' 97  '),
                 'Col2' = c('0.0', '0.27,0.91', '3.0', ' 10242.3', '  94.5'))

I would like to remove spaces from the cells only composed by numbers. Not sure if, for example, 0.52, that dot character makes it still be considered as number. Also in -0.88 the - character.

到目前为止，我会使用

library(stringr)
# Remove spaces
df$Col1 <- str_replace_all(df$Col1, "\\s+", "")

library(dplyr)
# Convert to as.numeric
df %>%
mutate_all(funs(as.numeric(as.character(.)))

But I would not like to just replace every single space, for example in the value 1.2 (ref), I would like to keep that space. Also, not to change every value to as.numeric, only where pure numbers, or \d+\.\d+, or \-\d+\.\d+ (regex)

Also if I attempt to convert to as.numeric, the numeric values somehow change drastically, I understand this is because of the spaces present in the values.

提前致谢