Sorting alphanumerically

Does this help?

ID <- paste("g", sample(1:100, 100, replace=FALSE), sep="")

ID
   [1] "g88"  "g5"   "g79"  "g67"  "g43"  "g21"  "g66"
   [8] "g9"   "g38"  "g86"  "g12"  "g85"  "g74"  "g34"
  [15] "g52"  "g95"  "g6"   "g22"  "g70"  "g87"  "g7"
  [22] "g83"  "g63"  "g42"  "g26"  "g65"  "g16"  "g97"
  [29] "g76"  "g2"   "g90"  "g23"  "g15"  "g82"  "g75"
  [36] "g58"  "g17"  "g20"  "g96"  "g91"  "g31"  "g33"
  [43] "g48"  "g32"  "g93"  "g54"  "g49"  "g36"  "g81"
  [50] "g57"  "g27"  "g14"  "g62"  "g10"  "g80"  "g71"
  [57] "g28"  "g37"  "g89"  "g8"   "g94"  "g68"  "g56"
  [64] "g92"  "g41"  "g11"  "g4"   "g99"  "g55"  "g60"
  [71] "g18"  "g69"  "g19"  "g64"  "g39"  "g1"   "g53"
  [78] "g44"  "g24"  "g100" "g35"  "g3"   "g40"  "g47"
  [85] "g51"  "g46"  "g61"  "g45"  "g50"  "g25"  "g13"
  [92] "g73"  "g77"  "g30"  "g84"  "g78"  "g29"  "g59"
  [99] "g72"  "g98"

ID[order(as.numeric(substr(ID, start=2, stop=nchar(ID))))]
   [1] "g1"   "g2"   "g3"   "g4"   "g5"   "g6"   "g7"
   [8] "g8"   "g9"   "g10"  "g11"  "g12"  "g13"  "g14"
  [15] "g15"  "g16"  "g17"  "g18"  "g19"  "g20"  "g21"
  [22] "g22"  "g23"  "g24"  "g25"  "g26"  "g27"  "g28"
  [29] "g29"  "g30"  "g31"  "g32"  "g33"  "g34"  "g35"
  [36] "g36"  "g37"  "g38"  "g39"  "g40"  "g41"  "g42"
  [43] "g43"  "g44"  "g45"  "g46"  "g47"  "g48"  "g49"
  [50] "g50"  "g51"  "g52"  "g53"  "g54"  "g55"  "g56"
  [57] "g57"  "g58"  "g59"  "g60"  "g61"  "g62"  "g63"
  [64] "g64"  "g65"  "g66"  "g67"  "g68"  "g69"  "g70"
  [71] "g71"  "g72"  "g73"  "g74"  "g75"  "g76"  "g77"
  [78] "g78"  "g79"  "g80"  "g81"  "g82"  "g83"  "g84"
  [85] "g85"  "g86"  "g87"  "g88"  "g89"  "g90"  "g91"
  [92] "g92"  "g93"  "g94"  "g95"  "g96"  "g97"  "g98"
  [99] "g99"  "g100"

The idea is to drop the leading "g", convert to numeric, and then order.

mtb954 mtb954 wrote:

I'm trying to sort a DATAFRAME by a column "ID" that contains
alphanumeric data. Specifically,"ID" contains integers all preceeded
by the character "g" as in:

g1, g6, g3, g19, g100, g2, g39

I am using the following code:

DATAFRAME=DATAFRAME[order(DATAFRAME1$ID),]

and was hoping it would sort the dataframe by ID in the following manner

g1, g2, g3, g6, g19, g39, g100

but it doesn't sort at all. Could anyone point out my mistake?

Thank you.

Mark

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