how to return number of decimal places in R

Question

I am working in R. I have a series of coordinates in decimal degrees, and I would like to sort these coordinates by how many decimal places these numbers have (i.e. I will w

Answer 1

Not sure why this simple approach was not used above (load the pipe from tidyverse/magrittr).

count_decimals = function(x) {
  #length zero input
  if (length(x) == 0) return(numeric())

  #count decimals
  x_nchr = x %>% abs() %>% as.character() %>% nchar() %>% as.numeric()
  x_int = floor(x) %>% abs() %>% nchar()
  x_nchr = x_nchr - 1 - x_int
  x_nchr[x_nchr < 0] = 0

  x_nchr
}

> #tests
> c(1, 1.1, 1.12, 1.123, 1.1234, 1.1, 1.10, 1.100, 1.1000) %>% count_decimals()
[1] 0 1 2 3 4 1 1 1 1
> c(1.1, 12.1, 123.1, 1234.1, 1234.12, 1234.123, 1234.1234) %>% count_decimals()
[1] 1 1 1 1 2 3 4
> seq(0, 1000, by = 100) %>% count_decimals()
 [1] 0 0 0 0 0 0 0 0 0 0 0
> c(100.1234, -100.1234) %>% count_decimals()
[1] 4 4
> c() %>% count_decimals()
numeric(0)

So R does not seem internally to distinguish between getting 1.000 and 1 initially. So if one has a vector input of various decimal numbers, one can see how many digits it initially had (at least) by taking the max value of the number of decimals.

Edited: fixed bugs