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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。7 P1 U& e) A$ p. y7 ~3 R1 s
netlogo自带的social science--traffic grid这一例子当中,
3 _/ ~; F& D0 e8 iglobals2 p' r3 O- q$ W4 U4 b5 i( d$ B
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. Y7 O' c& k- `7 ` grid-x-inc ;; the amount of patches in between two roads in the x direction
% P3 G0 b) h, h- f$ f* B; b grid-y-inc ;; the amount of patches in between two roads in the y direction3 A8 J7 o' S" F# w8 I
acceleration ;; the constant that controls how much a car speeds up or slows down by if; f$ A) @( N* c2 T. N
;; it is to accelerate or decelerate
6 u6 r9 v% m( n( R7 F% Q phase ;; keeps track of the phase
+ G: l& O. f+ g; s( h num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure3 h: D# |& }0 ]' F( m/ r
current-light ;; the currently selected light, _- T) L0 U1 b7 }. S: ?, M
! m$ R9 D% k8 c) j" ]& z6 {2 R) Q! Q ;; patch agentsets
2 f0 {$ ]* B$ E3 \6 T intersections ;; agentset containing the patches that are intersections8 ?: a) z7 B5 r+ p! z
roads ;; agentset containing the patches that are roads3 I$ |2 A: i6 b4 D6 H3 T
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; ~% G7 k# n" p8 G! ^: s$ oturtles-own
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speed ;; the speed of the turtle+ S$ O6 v2 \4 m0 I# R, Z6 Y' x
up-car? ;; true if the turtle moves downwards and false if it moves to the right
% q% c9 x' K$ P+ s& f4 N3 j wait-time ;; the amount of time since the last time a turtle has moved
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patches-own( }* s3 r' C- |$ @* H! H1 J
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* n$ S1 |0 M6 l: z& i" d intersection? ;; true if the patch is at the intersection of two roads6 g0 f" G3 h& y1 X4 p
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
8 f* A0 |) ?6 f) D9 o7 A ;; false for a non-intersection patches.
# ~% S- P( b8 u$ S0 O my-row ;; the row of the intersection counting from the upper left corner of the& i+ H6 M* b# x" D2 i& S& h1 o
;; world. -1 for non-intersection patches.
7 |/ k {& o ~* m, Y, F' P- q my-column ;; the column of the intersection counting from the upper left corner of the
% P1 x& L: \) E9 M3 ?8 b/ a ;; world. -1 for non-intersection patches.
3 L' m1 C P+ g R/ X my-phase ;; the phase for the intersection. -1 for non-intersection patches.
; b5 N* _. J0 L/ ]( G auto? ;; whether or not this intersection will switch automatically.
8 k9 D: ^0 |0 [! @* Y( S! Q ;; false for non-intersection patches.
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. A2 B2 ~& F' P# J$ L;;;;;;;;;;;;;;;;;;;;;;8 T" p- I; F# k3 b
;; Setup Procedures ;;
0 v! q8 N. M$ L;;;;;;;;;;;;;;;;;;;;;;: ?# }- P0 o0 v5 T$ l7 r
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;; Initialize the display by giving the global and patch variables initial values.* Y; e& }" q- T2 v
;; Create num-cars of turtles if there are enough road patches for one turtle to
# a9 n5 E/ b2 T" V( y9 `$ o;; be created per road patch. Set up the plots.$ X$ N' s2 w: m! _3 {1 R
to setup
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% H" G! }* A+ M6 B# P+ d! z7 s* o% m setup-globals
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. k! X) \2 L( [9 \' L* r } ;; First we ask the patches to draw themselves and set up a few variables
0 K# f. m7 ^, ?! } setup-patches. N* j7 p4 g* \- Z [$ c5 ?% }, q
make-current one-of intersections
! K7 B/ I5 P: e9 R# m% f2 U& p' p label-current
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S$ }' K1 n }- q0 g% h set-default-shape turtles "car"
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
3 r+ v1 z: U+ l' h "road. Either increase the amount of roads "
& q! G9 z8 `1 s1 C. Z "by increasing the GRID-SIZE-X or "
2 ^8 p5 Y! |1 Z "GRID-SIZE-Y sliders, or decrease the "
6 n$ u/ u$ W9 I6 K( \ "number of cars by lowering the NUMBER slider.\n"
* G! k! D9 Z& x4 y# f( C "The setup has stopped.")
" f2 [/ a0 z5 N8 A) S4 y1 n stop: L$ Q/ I" A) A
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# S N+ S# M% P5 C* i ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color: y' g. J5 o) r. _
crt num-cars" B4 U+ Z( Y& B3 D/ t: L
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% ^0 x' Z" v# s, i1 i8 ^8 P setup-cars
* ^6 F- A, V5 {( u5 N% `* H set-car-color
3 \+ m$ X5 U/ z: U* q3 y' k. V record-data9 c* G! S3 q& Q" `
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3 N" w, A. C ^" P$ U* B ;; give the turtles an initial speed: A! R5 }$ M* P5 d6 n
ask turtles [ set-car-speed ]
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reset-ticks
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/ ^6 H |. Y. R* f;; Initialize the global variables to appropriate values4 T* q/ C% b' G) ]$ s
to setup-globals
; A6 x, _. K, L5 _ set current-light nobody ;; just for now, since there are no lights yet
. _( j' A8 X- V( M+ Q set phase 0
( a7 [3 n3 ?+ H9 ~$ T2 m" _ set num-cars-stopped 0
5 h8 g# s$ x a" _6 a1 b, V set grid-x-inc world-width / grid-size-x
! w/ m3 L W0 `1 e8 W! _ set grid-y-inc world-height / grid-size-y4 R2 W+ n) K7 J1 W( F$ ? H
% {/ B+ S2 m& b9 n. R ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary' A6 h C4 P& ]
set acceleration 0.099
8 F- }6 q' z k( m/ G% ~4 W4 Uend
# L7 O9 |9 f5 h( M' j- ^ \7 N' Q' W6 `+ K' ~3 U1 n0 c
;; Make the patches have appropriate colors, set up the roads and intersections agentsets, z( O0 z" m7 R2 ]$ D) x
;; and initialize the traffic lights to one setting d1 }. W/ L8 K0 F9 i) R
to setup-patches
% x1 @. X- \: h# z ;; initialize the patch-owned variables and color the patches to a base-color( y3 o/ L9 {$ Q# B q/ i. E
ask patches
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" a0 P! a2 }. I0 T, v set intersection? false4 r$ x0 K% m4 a; Q, s, y5 P
set auto? false; e" p9 y8 ~; s2 q7 C/ X5 K; T: Q
set green-light-up? true
: `; l# H5 L- ^8 I6 i- v/ T" ` set my-row -1
" A& X- M4 G5 q: u) c r* P set my-column -1
% B( W1 B% K# F: U% m set my-phase -1) Z" o/ a$ {* L$ D1 @& n
set pcolor brown + 3
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$ K; V+ h+ I5 f; O ;; initialize the global variables that hold patch agentsets
$ j; q( r, I) U7 C% o1 O7 V set roads patches with
6 s7 X4 \ N$ B1 J [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or+ n3 r& d+ }0 _. G# ]
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]- |4 i9 t0 [8 v
set intersections roads with
; ?7 ]3 c) n# D9 h) k, A [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and: F* L* y' B/ O/ ^
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 [6 I- y/ Y3 z7 m O3 l& E
+ S* ^. x, O5 w* @" r1 j0 N% k ask roads [ set pcolor white ]9 h: U; M' I6 i7 g5 h/ n% [
setup-intersections! Y0 r, b7 S' u1 x7 h
end
_8 u3 [5 G: D5 Y其中定义道路的句子,如下所示,是什么意思啊?6 ^1 R7 a' Z% D. e
set roads patches with
8 U0 b- ?2 ?2 S, w# B' y( H: h0 [* m [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or: {! r; g9 q1 k# B% f6 ?
(floor((pycor + max-pycor) mod grid-y-inc) = 0)] X2 D! ^# d; }
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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