Environment and Scope rule in R

Learning Environment and Lexical Scope rule in R

Transcript

1. 3ͷ؀ڥͱείʔϓ *UPTIJ
   /*,"*%0
   ESJUPTIJ!HNBJMDPN 1
2. 3͸͢΂͕ͯΦϒδΣΫτ WFDUPS
   NBUSJY
   ؔ਺ ͻͱͭͷΫϥεʹଐ͢Δ 2
3. ΦϒδΣΫτΛ্ॻ͖͞Εͨ͘ͳ͍ ؔ਺Λݺͼग़͢ ύοέʔδΛಡΈࠐΉ 3
4. ͲͷΑ͏ͳ ΦϒδΣΫτ͕ར༻Մೳ͔ 4
5. -FYJDBM
   TDPQJOH ෳ਺ͷ؀ڥ͔ΒΦϒδΣΫτΛ୳͢ɾ؀ڥΛ࡞੒ ͢Δنଇ 5
6. FOWJSPONFOU
   ؀ڥ 6
7. FOWJSPONFOU
   
   GSBNF
   
   FODMPTVSF 7
8. FOWJSPONFOU
   
   GSBNF
   
   FODMPTVSF TZNCPM
   㱻
   WBMVF lYz
   㱻
    8
9. FOWJSPONFOU
   
   GSBNF
   
   FODMPTVSF ؀ڥ΁ͷQPJOUFS Ͳͷ؀ڥͱ݁ͼ͍͍ͭͯΔͷ͔ 9
10. globalenv() .GlobalEnv baseenv() emptyenv() ... ... ͍ΘΏΔϫʔΫεϖʔε ίϯιʔϧ΍εΫϦϓτ͔Βͷೖྗ͞ ΕͨΦϒδΣΫτ͕֨ೲ͞ΕΔ ※ ؔ਺΍ύοέʔδ͸ผ ؀ڥͷߏ଄ ઢܗͷπϦʔ 10
11. globalenv() R_GlobalEnv baseenv() base emptyenv() R_EmptyEnv ... ... search path: ΦϒδΣΫτ Λݕࡧ͢Δ؀ڥͷॱং search() 4FBSDI
    1BUI ΦϒδΣΫτΛݕࡧ͢Δॱং 11
12. globalenv() R_GlobalEnv baseenv() base emptyenv() R_EmpltyEnv ... ... ϩʔυ͞ΕͨΦϒδΣΫτ͸base ͱ.GlobalEnvͷؒʹஔ͔ΕΔ library() attach() 1BDLBHF
    ΍σʔλ͕ϩʔυ͞ΕΔͱ MJCSBSZ
    ͱ
    BUUBDI 12
13. globalenv() R_GlobalEnv baseenv() base emptyenv() R_EmpltyEnv ... ... ؔ਺Λݺͼग़͢ Ϋϩʔδϟʔ؀ڥΛݩʹ؀ڥ (ධՁ؀ڥ)͕࡞ΒΕͯɺ 1൪໨ʹஔ͔ΕΔ ؔ਺Λఆٛ͢Δͱ Ϋϩʔδϟ؀ڥ͕࡞ΒΕɺݺͼग़͞ΕΔͨͼʹධՁ؀ڥ͕ੜ੒͞ΕΔ ؔ਺Λఆٛ͢Δ ͦͷ؀ڥΛؚΉ؀ڥ͕࡞ΒΕΔ = closure ؀ڥ ؔ਺͕؀ڥͱηοτʹͳ͍ͬͯΔͷͰɺؔ਺͸ࣗ෼ͷ৔ॴΛ஌͍ͬͯΔɻ R ͸͜ΕΛར༻ͯ͠ΦϒδΣΫτΛ୳͢ɻ ͜ͷΑ͏ͳείʔϓنଇͷ͜ͱΛ Lexical scope ͱݺͿ ͜ͷΑ͏ͳؔ਺ͷ͜ͱΛΫϩʔδϟؔ਺ͱݺͿ 13
14. globalenv() R_GlobalEnv baseenv() base emptyenv() R_EmpltyEnv ... ... ؔ਺Λݺͼग़͢ Ϋϩʔδϟʔ؀ڥΛݩʹ؀ڥ (ධՁ؀ڥ)͕࡞ΒΕͯɺ 1൪໨ʹஔ͔ΕΔ ؔ਺ͷҾ਺͸͍ͭධՁ͞ΕΔͷ͔ DBMMCZWBMVF
    ͱ
    MB[Z
    FWBMVBUJPO ؔ਺Λఆٛ͢Δ ͦͷ؀ڥΛؚΉ؀ڥ͕࡞ΒΕΔ = closure ؀ڥ 1. ؔ਺͕ݺͼग़͞ΕΔͱɺධՁ؀ڥͷҾ਺ϚονϯάنଇͰ ԾҾ਺ͱ࣮Ҿ਺͕র߹͞ΕΔ 2. ؔ਺͕ධՁ͞ΕΔ 3. Ҿ਺͕ඞཁʹͳͬͨΒɺҾ਺Ͱ༩͑ΒΕͨ஋ʹॳظԽ͞ΕΔ (஗ԆධՁ) ͜ͷͱ͖஋ͷϙΠϯλͰ͸ͳ͘ɺ஋ͦͷ΋ͷʹஔ͖มΘΔ (஋౉͠) (஗ԆධՁ͸༧໿ΦϒδΣΫτͰୡ੒͍ͯ͠Δ͕આ໌ΛׂѪ) 14
15. globalenv() R_GlobalEnv baseenv() base emptyenv() R_EmpltyEnv ... αʔνύεΛ੍ޚ͍ͨ͠ αʔνύεͷྫ֎తͳॲཧͰ͋Δ໊લۭؒΛར༻͢Δ 0. ΦϒδΣΫτΛఏڙ͢Δύοέʔδ ͷ໊લۭؒ 1. Πϯϙʔτ͞ΕΦϒδΣΫτ 2. base ύοέʔδͷ໊લۭؒ 3. search path - ಉ໊ͷΦϒδΣΫτΛ۠ผ͢Δ - ΦϒδΣΫτͷΧϓηϧԽ Λ͢ΔͨΊͷྫ֎ = namespace 15
16. globalenv() R_GlobalEnv baseenv() base emptyenv() R_EmpltyEnv ... 3Ͱ؀ڥΛૢ࡞͢Δ ؀ڥͷ৘ใΛಘΔ search() searchpaths() topenv() parent.env() ݕࡧ͢Δ environment(ls) ଘࡏͷ֬ೝ exists(“+”, env = baseenv()) ؀ڥΛ࡞Δ e1 <- new.env() e1 16
17. baseenv() base emptyenv() R_EmpltyEnv 3Ͱ؀ڥΛૢ࡞͢Δ ؀ڥʹର͢Δม਺ͷૢ࡞ # ม਺ΛׂΓ౰ͯΔ > assign("a", 1:10, envir = baseenv()) # ݕࡧ͢Δ > exists("a", envir = globalenv(), inherits = FALSE) [1] FALSE > exists("a", envir = baseenv(), inherits = FALSE) [1] TRUE # ม਺Λݕࡧͯ͠ɺ஋ΛऔΓग़͢ > mget("a", envir = baseenv()) $a [1] 1 2 3 4 5 6 7 8 9 10 > get("a", envir = baseenv()) [1] 1 2 3 4 5 6 7 8 9 10 17
18. 3Ͱ໊લۭؒΛૢ࡞͢Δ ໊લۭؒͷ৘ใΛಘΔɾύοέʔδ಺ͷม਺ʹΞΫηε͢Δ # ม਺ʹΞΫηε͢Δ # Package::name # export() ͞Ε͍ͯΔؔ਺ base::log # Package:::name # export() ͞Ε͍ͯͳ͍ؔ਺ library(“Package”) Package:::name # ؔ਺Λద༻ eapply(env, FUN) # ໊લۭؒͷ৘ใ loadedNamespaces() # ໊લۭؒͷૢ࡞ loadNamespace(ns) unloadNamespace(ns) attachNamespace(ns) # ໊લۭؒͷ࡞੒ asNamespace(“name”) # ΤΫεϙʔτ namespaceExport(ns) 18
19. 3Ͱ͸؀ڥ͸ͲͷΑ͏ʹදݱ͞Ε͍ͯΔ͔ ࣮͸୯ͳΔ
    MJTU R> e <- new.env() R> e <environment: 0x103186150> R> e$a <- 1 R> e$b <- "hoge" R> e$b # ؀ڥΛ list ʹ͢Δ R> as.list(e) $a [1] 1 $b [1] "hoge" 19
20. ؀ڥ͸ࢀর౉͠ 3͸جຊతʹ஋౉͠Ͱ͋Δ͕؀ڥ͸ྫ֎ R> e <- new.env() R> e2 <- e R> e <environment: 0x103186150> R> e2 <environment: 0x103186150> # ಉ͡ϙΠϯλΛ͍ͯ͞͠Δ R> e$a NULL # e2 ʹ a Λͭ͘Δ R> e2$a <- 1 R> e2$a 1 # ࢀর౉͠ͳͷͰe ʹ΋ a ͕Ͱ͖͍ͯΔ R> e$a [1] 1 20
21. ·ͱΊ ΦϒδΣΫτΛ্ॻ͖ͨ͘͠ͳ͔ͬͨ • R͸ Lexical scope rule Ͱ࢖͑ΔΦϒδΣΫτΛ஌Δ͜ͱ͕Ͱ͖Δ • R͸؀ڥʹΑͬͯ Lexical scope Λୡ੒͍ͯͨ͠ • Ϣʔβ͕؀ڥΛ࡞Δ͜ͱͰείʔϓϧʔϧʹج͍ͨΦϒδΣΫτΛੜ ੒ɾ؅ཧͰ͖Δ • NamespaceͰείʔϓϧʔϧͷྫ֎Λ࡞ΓɺϢʔβ͕ͦͷείʔϓൣғ ΛܾΊΔ͜ͱ͕Ͱ͖ΔɻRͰ͸ޙ෇͚ͷ࣮૷ͳͷͰࠓͰ΋࢓༷͕एׯม Խத 21
22. ࢀߟࢿྉ ࿦จɺΦϯϥΠϯυΩϡϝϯτɺॻ੶ • Lexical Scope and Statistical Computing • The R Language Definition • RϓϩάϥϛϯάϚχϡΞϧ • Rͷجૅͱϓϩάϥϛϯάٕ๏ 22