循环遍历列以删除 NA

Question

I am trying to transform column data to numeric and round my numbers for each column in my data frame. I can do this manually for each column which I originally did. But now I am wondering how I could loop through my data's column so I don't have to do it manually in the future.

An example line of manually doing it is:

data$`Impacts` <- round(as.numeric(data$`Impacts`),2)

But for implementing the for loop, I have tried the following code:

data <- import(from desktop/wherever/etc.)
i <- 9
for (i in data) {
 data[c(i)] <- round(as.numeric(data[c(i)]),2)
 i <- i + 1
}

And this returns an error of:

Error in `[.data.frame`(data, c(i)) : undefined columns selected

I tried to edit my for loop my replacing data[c(i)] with data[,c(i)] and data$[,c(i)] but neither of those fixed it.

I would have thought that the columns were defined as I go through the data starting at column 9 and increment through each column with i + 1

Am I missing something obvious? Thanks

Answer 1

We can use lapply :

data[] <- lapply(data, function(x) round(as.numeric(x),2))

Or using dplyr :

library(dplyr)
data %>%  summarise_all(~round(as.numeric(.), 2))

---

If you want to round only specific columns say 1:3 , you can do

data[1:3] <- lapply(data[1:3], function(x) round(as.numeric(x),2))

and

data %>% summarise_at(1:3, ~round(as.numeric(.), 2))