์๋ ํ์ธ์!
์ฌํ ๊ฐ๋ฅํ ์ต์ ์ :
library(data.table)
f = function(flag = FALSE) {
dt1 = data.table(a = 1)
dt2 = data.table(a = 1)
dt3 = dt1[, .(a, b = 0)]
print(body(f))
if (flag) dt3[dt2, b := 999, on = "a"]
print(body(f))
return(invisible(dt3))
}
f(flag = FALSE)
f(flag = TRUE)
> f(flag = FALSE)
{
dt1 = data.table(a = 1)
dt2 = data.table(a = 1)
dt3 = dt1[, .(a, b = 0)]
print(body(f))
if (flag)
dt3[dt2, `:=`(b, 999), on = "a"]
print(body(f))
return(invisible(dt3))
}
{
dt1 = data.table(a = 1)
dt2 = data.table(a = 1)
dt3 = dt1[, .(a, b = 0)]
print(body(f))
if (flag)
dt3[dt2, `:=`(b, 999), on = "a"]
print(body(f))
return(invisible(dt3))
}
> f(flag = TRUE)
{
dt1 = data.table(a = 1)
dt2 = data.table(a = 1)
dt3 = dt1[, .(a, b = 0)]
print(body(f))
if (flag)
dt3[dt2, `:=`(b, 999), on = "a"]
print(body(f))
return(invisible(dt3))
}
{
dt1 = data.table(a = 1)
dt2 = data.table(a = 1)
dt3 = dt1[, .(a, b = 999)]
print(body(f))
if (flag)
dt3[dt2, `:=`(b, 999), on = "a"]
print(body(f))
return(invisible(dt3))
}
๋ณด์๋ค์ํผ "b"์ด์ ์ ๊ฐ์ ํ ๋น (: =) ํ ํ (ํ๋๊ทธ๊ฐ TRUE ์ผ ๋) "f"ํจ์์ ๋ณธ๋ฌธ์ด "dt3 = ..."์ค์์ ๋ณ๊ฒฝ๋ฉ๋๋ค ( "b = 0 "๋"b = 999 "๋ก ๋์ฒด๋ฉ๋๋ค). FALSE ํ๋๊ทธ ๊ฐ์ผ๋ก ์คํํ๋ฉด ํจ์ ์คํ ๊ฒฐ๊ณผ๊ฐ ๋ฌ๋ผ์ง๋๋ค.
sessionInfo ()์ ์ถ๋ ฅ :
R version 3.5.1 (2018-07-02)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 7 x64 (build 7600)
Matrix products: default
locale:
[1] LC_COLLATE=Russian_Russia.1251 LC_CTYPE=Russian_Russia.1251 LC_MONETARY=Russian_Russia.1251
[4] LC_NUMERIC=C LC_TIME=Russian_Russia.1251
attached base packages:
[1] stats graphics grDevices utils datasets methods base
other attached packages:
[1] data.table_1.12.3
loaded via a namespace (and not attached):
[1] compiler_3.5.1 tools_3.5.1 yaml_2.2.0
ํ๋ฅญํ ๋ณด๊ณ ์์ ๊ฐ์ฌ๋๋ฆฝ๋๋ค! v1.12.2์์๋ ์ฌํ ํ ์ ์์ต๋๋ค.
@mattdowle , ๊ฐ์ฌํฉ๋๋ค!
์ถ๊ฐ ์กฐ์ฌ ํ ๋ํผ ๊ธฐ๋ฅ์ด ํ์ํ์ง ์์์ด ๋ฐํ์ก์ต๋๋ค.
์ด ๋ฌธ์ ์ ๋ํ ๊ฐ๊ฒฐํ ์๋ ๋ค์๊ณผ ๊ฐ์ต๋๋ค.
library(data.table)
value = 0
dt1 = data.table(a = 1)
dt2 = dt1[, .(a, b = ..value)]
dt2[1, b := 999]
print(value)
๊ฐ์ฌ. ๋๋ ์ด์ ๊ฒฐํจ์ด์๋ ๋ผ์ธ์ ๋ฐ๊ฒฌํ๊ณ ๊ทธ๊ฒ์ด ๋จ์ง ๋ํผ๊ฐ ์๋์ง ๊ถ๊ธํ๋ค. ๋ฐ๋ผ์ ์ด๋ฏธ ์์ ๊ฐ์๋ ๊ฒ์ด ์ ๋ง ์ข์ต๋๋ค. WIP ...
๊ด๋ จ # 3766. ์ฐ๋ฆฌ๋ฅผ ํฌ๊ธฐํ์ง ์์ @kirillmayantsev ์๊ฒ ๊ฐ์ฌ๋๋ฆฝ๋๋ค!
๊ฐ์ฅ ์ ์ฉํ ๋๊ธ
@mattdowle , ๊ฐ์ฌํฉ๋๋ค!
์ถ๊ฐ ์กฐ์ฌ ํ ๋ํผ ๊ธฐ๋ฅ์ด ํ์ํ์ง ์์์ด ๋ฐํ์ก์ต๋๋ค.
์ด ๋ฌธ์ ์ ๋ํ ๊ฐ๊ฒฐํ ์๋ ๋ค์๊ณผ ๊ฐ์ต๋๋ค.