Às 19:35 de 18/10/2023, Leonard Mada escreveu:
Dear Rui,
On 10/18/2023 8:45 PM, Rui Barradas wrote:
split_chem_elements <- function(x, rm.digits = TRUE) {
regex <- "(?<=[A-Z])(?![a-z]|$)|(?<=.)(?=[A-Z])|(?<=[a-z])(?=[^a-z])"
if(rm.digits) {
stringr::str_replace_all(mol, regex, "#") |>
strsplit("#|[[:digit:]]") |>
lapply(\(x) x[nchar(x) > 0L])
} else {
strsplit(x, regex, perl = TRUE)
}
}
split.symbol.character = function(x, rm.digits = TRUE) {
# Perl is partly broken in R 4.3, but this works:
regex <- "(?<=[A-Z])(?![a-z]|$)|(?<=.)(?=[A-Z])|(?<=[a-z])(?=[^a-z])"
s <- strsplit(x, regex, perl = TRUE)
if(rm.digits) {
s <- lapply(s, \(x) x[grep("[[:digit:]]+", x, invert = TRUE)])
}
s
}
You have a glitch (mol is hardcoded) in the code of the first function.
The times are similar, after correcting for that glitch.
Note:
- grep("[[:digit:]]", ...) behaves almost twice as slow as grep("[0-9]",
...)!
- corrected results below;
Sincerely,
Leonard
#######
split_chem_elements <- function(x, rm.digits = TRUE) {
regex <- "(?<=[A-Z])(?![a-z]|$)|(?<=.)(?=[A-Z])|(?<=[a-z])(?=[^a-z])"
if(rm.digits) {
stringr::str_replace_all(x, regex, "#") |>
strsplit("#|[[:digit:]]") |>
lapply(\(x) x[nchar(x) > 0L])
} else {
strsplit(x, regex, perl = TRUE)
}
}
split.symbol.character = function(x, rm.digits = TRUE) {
# Perl is partly broken in R 4.3, but this works:
regex <- "(?<=[A-Z])(?![a-z]|$)|(?<=.)(?=[A-Z])|(?<=[a-z])(?=[^a-z])"
s <- strsplit(x, regex, perl = TRUE)
if(rm.digits) {
s <- lapply(s, \(x) x[grep("[0-9]", x, invert = TRUE)])
}
s
}
mol <- c("CCl3F", "Li4Al4H16", "CCl2CO2AlPO4SiO4Cl")
mol10000 <- rep(mol, 10000)
system.time(
split_chem_elements(mol10000)
)
# user system elapsed
# 0.58 0.00 0.58
system.time(
split.symbol.character(mol10000)
)
# user system elapsed
# 0.67 0.00 0.67
Hello,
You are right, sorry for the blunder :(.
In the code below I have replaced stringr::str_replace_all by the
package stringi function stri_replace_all_regex and the improvement is
significant.
split_chem_elements <- function(x, rm.digits = TRUE) {
regex <- "(?<=[A-Z])(?![a-z]|$)|(?<=.)(?=[A-Z])|(?<=[a-z])(?=[^a-z])"
if(rm.digits) {
stringi::stri_replace_all_regex(x, "#", regex) |>
strsplit("#|[0-9]") |>
lapply(\(x) x[nchar(x) > 0L])
} else {
strsplit(x, regex, perl = TRUE)
}
}
# system.time(
# split_chem_elements(mol10000)
# )
# user system elapsed
# 0.06 0.00 0.09
# system.time(
# split.symbol.character(mol10000)
# )
# user system elapsed
# 0.25 0.00 0.28
Hope this helps,
Rui Barradas
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