Convert Character with precision

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whereas the content of a certain variable is "001" class Character.

I need to transform that character to numeric. If I do as.numeric(), he returns me 1.

I want you to return me exactly 001, is it possible?

Thank you.

r
  • 1

    001 is not exactly a number, maybe you should work with text yourself. If you tell me what you want to achieve that you need 00 up front maybe somebody can help you.

  • In fact, I have a database where one of the columns calls "Code" . In this column I have characters like this. For example, "00010" or "01234". I need to select from this database the lines that have certain codes.. for example, I want to select only the code lines "00010" and "00020". When I do something like desp2<- desp2[ desp2$codigo == "00020" | "00020",] give me an error, because this logical operator does not work with characters. Hence my need to convert to numeric

  • It’s best to work with characters.

  • I modified my previous comment... now I think it’s clearer what I want

  • 1

    How’s the type of your "Code" field in your BD? If it’s not numerical it won’t do you much good to search with numbers.

  • Good afternoon @Vasco, but it would not be better to adapt the database by changing the column to numeric?

  • Vasco, the == should be functioning normally, even if character. The problem is probably something else, if you put an example of the data and the code becomes easier to help, abs.

  • I want to turn that column into numeric. I had a sun, I added digit 1 in all rows of the code column as first digit. So, it’s time to turn Character to numeric, I don’t lose its original location.But even so, at the time I desp2<- desp2[ desp2$codigo_novo == 1049 | 1001,] it seems that the selection is not successful, because the number of lines ends up being the same. On the other hand, when I desp2<- desp2[ desp2$codigo_new == 1001,] the selection is successful, because the number of lines is smaller.

  • Guys, @Carloscinelli .. I managed to solve my problem using the subset function even with characater... thanks guys

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The problem is in == and not in class. The == works only for one value. To compare with more than one value, it has to be %in%. In your case:

desp2[desp2$codigo_novo %in% c('1049', '1001'),]

Similarly in the subset:

subset(desp2, codigo_novo %in% c('1049', '1001'))

Using the ==, two comparisons would be necessary:

desp2$codigo_novo == '1049' | desp2$codigo_novo == '1001'

  • What if I want to use a sequence of codes? For example, I need to select the lines whose codes are continuously from "1049" to "1080" ... How I would avoid writing code by code?

  • 1

    Da to use codigo_novo %in% 1049:1090 (1049:1090 returns a vector with the integers between 1049 and 1090). Although it is a number, it will be transformed into a string at the time of comparison. Note that it will only work because the number has 4 characters, if you have less you will have to use the sprintf() to add the 0 to the left (Ex: sprintf('%04d', c(1, 10, 100, 1000)))

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