Truncating numbers but they are not showing up the right number of characters

I am trying to extract the first 6 numbers for the hs10 variable, but I've been getting only 5 characters for some - is there a reason for this?

I have used this function

us_chn_tariffs_18$HS6 <- as.numeric(substr(format(us_chn_tariffs_18$hs10, scientific = F), 1, 6))

The dput is:

structure(list(hs10 = structure(c(208100000, 208902500, 301110010, 
301110020, 301110090, 301990390, 302230000, 302290110, 302290190, 
302420000, 302455000, 302595010, 302595090, 302740000, 302845000, 
302895077, 302912000, 303120022, 303120032, 303230000), label = "HS10 Product Code", format.stata = "%10.0f"), 
tariff_max = structure(c(0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 
0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 
0.1), label = "US Import Tariff Increase (max)", format.stata = "%9.3f"), 
tariff_scaled = structure(c(0.0333333350718021, 0.0333333350718021, 
0.0333333350718021, 0.0333333350718021, 0.0333333350718021, 
0.0333333350718021, 0.0333333350718021, 0.0333333350718021, 
0.0333333350718021, 0.0333333350718021, 0.0333333350718021, 
0.0333333350718021, 0.0333333350718021, 0.0333333350718021, 
0.0333333350718021, 0.0333333350718021, 0.0333333350718021, 
0.0333333350718021, 0.0333333350718021, 0.0333333350718021
), label = "US Import Tariff Increase (scaled)", format.stata = "%9.3f"), 
effective_mdate = structure(c(704, 704, 704, 704, 704, 704, 
704, 704, 704, 704, 704, 704, 704, 704, 704, 704, 704, 704, 
704, 704), label = "Month Variety First Targeted", format.stata = "%tm"), 
month = c("9", "9", "9", "9", "9", "9", "9", "9", "9", "9", 
"9", "9", "9", "9", "9", "9", "9", "9", "9", "9"), treated = c(1, 
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1), 
HS6 = structure(c(20810, 20890, 30111, 30111, 30111, 30199, 
30223, 30229, 30229, 30242, 30245, 30259, 30259, 30274, 30284, 
30289, 30291, 30312, 30312, 30323), label = "HS10 Product Code", format.stata = "%10.0f")), row.names = c(NA, 
-20L), class = c("tbl_df", "tbl", "data.frame"))

Thank you

I think I can see where the problem comes in, but cannot reproduce it quite exactly (as I've not imported from Stata). The Stata print format is %10.0f, which prints 10 characters, padding your digits with leading spaces. But your IDs are all 9 digits long, so the first character pulled from substr is a space, which as.numeric trims. Try reformating hs10:

hs10 <-  c(
  208100000,
  208902500,
  301110010,
  301110020,
  301110090,
  301990390,
  302230000,
  302290110,
  302290190,
  302420000,
  302455000,
  302595010,
  302595090,
  302740000,
  302845000,
  302895077,
  302912000,
  303120022,
  303120032,
  303230000
)

# Reproducing the values you're getting

hs10_not_working <- sprintf(fmt = "%10.0f", hs10)

as.numeric(substr(format(hs10_not_working, scientific = F), 1, 6))
#>  [1] 20810 20890 30111 30111 30111 30199 30223 30229 30229 30242 30245 30259
#> [13] 30259 30274 30284 30289 30291 30312 30312 30323

# Corrected values

hs10_edited <- sprintf(fmt = "%-10.0f", hs10)

as.numeric(substr(format(hs10_edited, scientific = F), 1, 6))
#>  [1] 208100 208902 301110 301110 301110 301990 302230 302290 302290 302420
#> [11] 302455 302595 302595 302740 302845 302895 302912 303120 303120 303230

The new sprintf(fmt = "%-10.0f", hs10) part will left-align the numbers (- character) which will then mean the first 6 digits are extracted even if the value is only 9 digits.

Another simple solution would be to trimws before substring your variable:

us_chn_tariffs_18$HS6 <- as.numeric(substr(trimws(format(us_chn_tariffs_18$hs10, scientific = F)), 1, 6))