basestrsplit 에서 사용 하는 또 다른 벤치 마크 는 현재 열의 쉼표로 구분 된 문자열을 별도의 행 으로 분할하는 데 권장 될 수 있습니다 . 다양한 크기에서 가장 빠르기 때문입니다.
s <- strsplit(v$director, ",", fixed=TRUE)
s <- data.frame(director=unlist(s), AB=rep(v$AB, lengths(s)))
사용 fixed=TRUE은 타이밍에 상당한 영향을 미칩니다.
비교 방법 :
met <- alist(base = {s <- strsplit(v$director, ",") #Matthew Lundberg
s <- data.frame(director=unlist(s), AB=rep(v$AB, sapply(s, FUN=length)))}
, baseLength = {s <- strsplit(v$director, ",") #Rich Scriven
s <- data.frame(director=unlist(s), AB=rep(v$AB, lengths(s)))}
, baseLeFix = {s <- strsplit(v$director, ",", fixed=TRUE)
s <- data.frame(director=unlist(s), AB=rep(v$AB, lengths(s)))}
, cSplit = s <- cSplit(v, "director", ",", direction = "long") #A5C1D2H2I1M1N2O1R2T1
, dt = s <- setDT(v)[, lapply(.SD, function(x) unlist(tstrsplit(x, "," #Jaap
, fixed=TRUE))), by = AB][!is.na(director)]
#, dt2 = s <- setDT(v)[, strsplit(director, "," #Jaap #Only Unique
# , fixed=TRUE), by = .(AB, director)][,.(director = V1, AB)]
, dplyr = {s <- v %>% #Jaap
mutate(director = strsplit(director, ",", fixed=TRUE)) %>%
unnest(director)}
, tidyr = s <- separate_rows(v, director, sep = ",") #Jaap
, stack = s <- stack(setNames(strsplit(v$director, ",", fixed=TRUE), v$AB)) #Jaap
#, dt3 = {s <- setDT(v)[, strsplit(director, ",", fixed=TRUE), #Uwe #Only Unique
# by = .(AB, director)][, director := NULL][, setnames(.SD, "V1", "director")]}
, dt4 = {s <- setDT(v)[, .(director = unlist(strsplit(director, "," #Uwe
, fixed = TRUE))), by = .(AB)]}
, dt5 = {s <- vT[, .(director = unlist(strsplit(director, "," #Uwe
, fixed = TRUE))), by = .(AB)]}
)
도서관 :
library(microbenchmark)
library(splitstackshape) #cSplit
library(data.table) #dt, dt2, dt3, dt4
#setDTthreads(1) #Looks like it has here minor effect
library(dplyr) #dplyr
library(tidyr) #dplyr, tidyr
데이터:
v0 <- data.frame(director = c("Aaron Blaise,Bob Walker", "Akira Kurosawa",
"Alan J. Pakula", "Alan Parker", "Alejandro Amenabar", "Alejandro Gonzalez Inarritu",
"Alejandro Gonzalez Inarritu,Benicio Del Toro", "Alejandro González Iñárritu",
"Alex Proyas", "Alexander Hall", "Alfonso Cuaron", "Alfred Hitchcock",
"Anatole Litvak", "Andrew Adamson,Marilyn Fox", "Andrew Dominik",
"Andrew Stanton", "Andrew Stanton,Lee Unkrich", "Angelina Jolie,John Stevenson",
"Anne Fontaine", "Anthony Harvey"), AB = c('A', 'B', 'A', 'A', 'B', 'B', 'B', 'A', 'B', 'A', 'B', 'A', 'A', 'B', 'B', 'B', 'B', 'B', 'B', 'A'))
계산 및 타이밍 결과 :
n <- 10^(0:5)
x <- lapply(n, function(n) {v <- v0[rep(seq_len(nrow(v0)), n),]
vT <- setDT(v)
ti <- min(100, max(3, 1e4/n))
microbenchmark(list = met, times = ti, control=list(order="block"))})
y <- do.call(cbind, lapply(x, function(y) aggregate(time ~ expr, y, median)))
y <- cbind(y[1], y[-1][c(TRUE, FALSE)])
y[-1] <- y[-1] / 1e6 #ms
names(y)[-1] <- paste("n:", n * nrow(v0))
y #Time in ms
# expr n: 20 n: 200 n: 2000 n: 20000 n: 2e+05 n: 2e+06
#1 base 0.2989945 0.6002820 4.8751170 46.270246 455.89578 4508.1646
#2 baseLength 0.2754675 0.5278900 3.8066300 37.131410 442.96475 3066.8275
#3 baseLeFix 0.2160340 0.2424550 0.6674545 4.745179 52.11997 555.8610
#4 cSplit 1.7350820 2.5329525 11.6978975 99.060448 1053.53698 11338.9942
#5 dt 0.7777790 0.8420540 1.6112620 8.724586 114.22840 1037.9405
#6 dplyr 6.2425970 7.9942780 35.1920280 334.924354 4589.99796 38187.5967
#7 tidyr 4.0323765 4.5933730 14.7568235 119.790239 1294.26959 11764.1592
#8 stack 0.2931135 0.4672095 2.2264155 22.426373 289.44488 2145.8174
#9 dt4 0.5822910 0.6414900 1.2214470 6.816942 70.20041 787.9639
#10 dt5 0.5015235 0.5621240 1.1329110 6.625901 82.80803 636.1899
참고, 다음과 같은 방법
(v <- rbind(v0[1:2,], v0[1,]))
# director AB
#1 Aaron Blaise,Bob Walker A
#2 Akira Kurosawa B
#3 Aaron Blaise,Bob Walker A
setDT(v)[, strsplit(director, "," #Jaap #Only Unique
, fixed=TRUE), by = .(AB, director)][,.(director = V1, AB)]
# director AB
#1: Aaron Blaise A
#2: Bob Walker A
#3: Akira Kurosawa B
을 반환 strsplit에 대한 unique 감독 과 대등 수 있습니다
tmp <- unique(v)
s <- strsplit(tmp$director, ",", fixed=TRUE)
s <- data.frame(director=unlist(s), AB=rep(tmp$AB, lengths(s)))
그러나 내 이해에 이것은 요청되지 않았습니다.
