R Divide all rows of a dataframe column by a number

Question

I am trying to divide all rows of my dataframe column by a number (say 10). I thought it to be a trivial problem until I tried it. In the example below, I am trying to get the 'mm' column to result in values 8100, 3222.2 and 5433.3

test <- data.frame(locations=c("81000","32222","54333"), value=c(87,54,43))
test$mm <- as.numeric(test$locations) / 10
head(test)
     locations value  mm
   1     81000    87 0.3
   2     32222    54 0.1
   3     54333    43 0.2

What am I doing wrong?

locations is not a number, it's a character, remove the commas — Matias Andina, Apr 18 '18 at 15:09
Either specify `stringsAsFactors = FALSE` within `data.frame` or don't quote `locations` (e.g., `locations=c(81000,32222,54333)`), or see the dupe target — David Arenburg, Apr 18 '18 at 15:12

score 5 · Accepted Answer · answered Apr 18 '18 at 15:09

5

Change factors to be character, then apply as.numeric

> test$mm <- as.numeric(as.character(test$locations)) / 10
> test
  locations value     mm
1     81000    87 8100.0
2     32222    54 3222.2
3     54333    43 5433.3

answered Apr 18 '18 at 15:09

Jilber Urbina

58,147
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Thanks for the response. It works. I did not realize that my column was a factor rather than a character. I will accept the answer. – ds_student Apr 18 '18 at 15:15

R Divide all rows of a dataframe column by a number

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