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rformatnumber-formatting

Convert scientific notation to numeric, preserving decimals

For some reason, when I convert a character column of numbers in scientific notation, the decimals aren't preserved.

> str(output)
'data.frame':   213950 obs. of  2 variables:
 $ ColA    : chr  ".3370E+03" ".3375E+03" ".3380E+03" ".3385E+03" ...
 $ ColB    : chr  ".4942E+00" ".5295E+00" ".5682E+00" ".6091E+00" ...

> output$ColA = as.numeric(output$ColA)

> str(output)
'data.frame':   213950 obs. of  2 variables:
 $ ColA    : num  337 338 338 338 339 ...
 $ ColB    : chr  ".4942E+00" ".5295E+00" ".5682E+00" ".6091E+00" ...

I would expect it to read:

$ ColA    : num  337 337.5 338 338.5 ...

I tried the solution from this SO question, but no luck:

> options(digits=9)
> str(output)
'data.frame':   213950 obs. of  2 variables:
 $ ColA      : num  337 338 338 338 339 ...
 $ ColB      : chr  ".4942E+00" ".5295E+00" ".5682E+00" ".6091E+00" ...

What's going on?

Solution

  • You can turn off scientific notation for numbers using the option below;

    options(scipen = 999)

    That would make all the numbers to appear as decimals.

    If you want to revert it back to the default, use

    options(scipen = 0)

    See getOption("scipen") for more options.