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新手,在看netlogo自带的例子时,有几行程序看不懂,希望高手能够指点。
' R/ _# N" @) f6 Y. Jnetlogo自带的social science--traffic grid这一例子当中,
. X" h: G: p! F8 T' ~globals( @) `( a6 Q9 ~/ e4 r2 X
[
+ d6 D: G8 I @; ]. h7 l: U grid-x-inc ;; the amount of patches in between two roads in the x direction
7 [: I ~" y, i( U! e) j$ @, _) i% n grid-y-inc ;; the amount of patches in between two roads in the y direction6 v/ H" f4 F9 J% ]* ]
acceleration ;; the constant that controls how much a car speeds up or slows down by if9 g3 W3 t: C* z7 f$ c" b/ U: P
;; it is to accelerate or decelerate) _; `6 Q" J" o; C0 C2 V/ ^' q
phase ;; keeps track of the phase
8 x" u1 K+ d) w' p num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
' J5 h5 \; l" T Z' s current-light ;; the currently selected light: G! Y0 j7 b* {. V" i* G& }5 j
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;; patch agentsets
' ? D; K" w* W$ D# F& `% Q intersections ;; agentset containing the patches that are intersections
& a, V0 \$ k4 ?- Z3 j roads ;; agentset containing the patches that are roads
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8 t! {& |9 ?$ D9 c$ Gturtles-own0 {& y+ g& o! C8 s6 @5 v5 [5 i% C
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speed ;; the speed of the turtle/ f# l. K3 _8 V* \
up-car? ;; true if the turtle moves downwards and false if it moves to the right
5 F1 v' j/ w! E0 k; X wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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& j0 U+ o' c- d6 A intersection? ;; true if the patch is at the intersection of two roads
M; X$ c r" s- ?6 F5 p. X green-light-up? ;; true if the green light is above the intersection. otherwise, false.4 J5 x8 j; U5 i; W
;; false for a non-intersection patches., q% l2 U3 I( X. G# O
my-row ;; the row of the intersection counting from the upper left corner of the/ J# j/ O1 E. k8 o2 u
;; world. -1 for non-intersection patches.
3 M& a/ S8 G" U7 X6 J9 @ my-column ;; the column of the intersection counting from the upper left corner of the/ k1 k% J; @# \
;; world. -1 for non-intersection patches.1 t( n: f- \" ]% M
my-phase ;; the phase for the intersection. -1 for non-intersection patches.$ `4 {: U R% `* F
auto? ;; whether or not this intersection will switch automatically." r3 b! T" D: a9 h8 k( h; M v
;; false for non-intersection patches.: C! B( o* p. F8 H7 ^
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;;;;;;;;;;;;;;;;;;;;;;! c& a4 K( t, u! I
;; Setup Procedures ;;
% e6 G4 x- P+ L0 g;;;;;;;;;;;;;;;;;;;;;;
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' P# d+ `3 Q `0 X2 F;; Initialize the display by giving the global and patch variables initial values.1 L# W0 ^, [9 e5 S' d" K ]
;; Create num-cars of turtles if there are enough road patches for one turtle to
7 B% X9 `. C' j/ W;; be created per road patch. Set up the plots.! c1 v! e/ Y% f" b4 v# X
to setup& J$ L& a$ x/ h; L8 r' o
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables; W/ w& v7 f0 k( J- v
setup-patches
5 l. [* z3 K7 I6 i* H make-current one-of intersections
+ L; C% c5 Y# g label-current
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set-default-shape turtles "car"% C4 ^0 q) v2 Y h% p2 {( N: ^; I
; Q( W. i% C4 L7 g if (num-cars > count roads)
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: R; m# R, o" [- R- g7 l' i user-message (word "There are too many cars for the amount of "$ V+ t( C' P0 |
"road. Either increase the amount of roads "8 |; [4 ?+ Z4 ]+ J Y0 ?
"by increasing the GRID-SIZE-X or "6 _% G7 t: y& o) z6 [& B
"GRID-SIZE-Y sliders, or decrease the "
. y4 |4 R' l) @: K2 i4 R2 J "number of cars by lowering the NUMBER slider.\n", E& f8 c& ?+ N9 z @7 ^0 I
"The setup has stopped."); a- Y0 G8 P, a! C% }5 E$ V
stop" E! ]; R6 h' ]! U" b
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S. }# F) _6 ^4 A' Y. C) \ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
. f! P) q. f7 }% l4 ]) V! x% _ crt num-cars
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! r: u& k5 `4 k/ J, S: C setup-cars" h" J, ~) v* I8 J
set-car-color8 k5 g6 d/ c8 C# G
record-data4 s/ r; I7 E# q) N! @
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4 m+ D, s3 ^4 E1 C& J ;; give the turtles an initial speed
$ o) }7 z. X- m3 S7 J ask turtles [ set-car-speed ]* L- X$ I6 u& \/ r
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reset-ticks
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;; Initialize the global variables to appropriate values
/ ~" _' X1 ~) oto setup-globals
) J8 {- w8 s6 c. U" u1 k set current-light nobody ;; just for now, since there are no lights yet
7 x$ j2 z1 k0 H. j1 A set phase 04 w4 s. T3 x; ^2 U8 y
set num-cars-stopped 0. Z& S( J A! g/ s# S& s' O. I' \
set grid-x-inc world-width / grid-size-x
6 P$ [9 Y# D; C! A" q$ A+ u3 O' {6 O set grid-y-inc world-height / grid-size-y
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3 x" a# y |1 M [ ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary* Z5 \0 t5 O* o" R
set acceleration 0.0993 | @4 ~3 @) Z0 B: g% E
end& Z) l% k( O2 i$ Z1 f
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
: L4 e9 [; T0 Z/ n6 g;; and initialize the traffic lights to one setting
% \: P3 I% h0 @( ~8 jto setup-patches, G; s+ @3 [4 g- ^ n6 L# P
;; initialize the patch-owned variables and color the patches to a base-color! T: {0 P+ u! E+ y3 s
ask patches
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8 g/ q# h- R1 @: B- I3 M4 c! G8 {' S set intersection? false# r6 Z8 O8 j2 ^9 h" ?) t3 Q# y0 @
set auto? false
( X) @$ g5 s5 A set green-light-up? true! T: T0 s; z% Y- _+ J; T3 a
set my-row -1
' W5 w6 @! p3 o `$ C3 @6 ^1 L: G set my-column -1" M4 H+ S# E- ^ Q5 F+ \: ]
set my-phase -1& P, h( A. B5 t
set pcolor brown + 3' A# |- i; S8 ]( j
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8 P: v" L4 c- f- ^( n) x" u1 ~, Y ;; initialize the global variables that hold patch agentsets c: Z/ h. b0 ~& t) P) @- S
set roads patches with
$ s% U$ O$ G: P* N3 M' c [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
$ [( u- W) |+ [; H4 O/ ? (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
" v9 [5 `5 J& ]7 R! ~ e6 t set intersections roads with$ E6 n% P8 C5 x# S5 l" {0 i& P' V+ t
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and9 _- l! l4 J" d& l) a4 q9 S
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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4 J* [& y" ?) v0 m' b* t( S ask roads [ set pcolor white ] B! a3 f2 E3 o1 y, U ~2 H5 x
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?6 n- i0 d! x) R! ?; {6 t/ _
set roads patches with6 x8 ]1 ^$ u. u5 f' ^: Z
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' z4 K5 N V; W7 S (floor((pycor + max-pycor) mod grid-y-inc) = 0)]: @3 Z6 u- l- a R1 o& J4 ]6 O' W
谁能帮我解释一下[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0)是什么意思吗? |
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