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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。) [! z( N2 K8 L8 V: m5 m# a7 h5 f
netlogo自带的social science--traffic grid这一例子当中,
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2 I" {: f9 ^3 R+ F grid-x-inc ;; the amount of patches in between two roads in the x direction
1 Y& Q9 u$ B! L' k grid-y-inc ;; the amount of patches in between two roads in the y direction3 R+ R c# x E& V* b7 `* C' \9 I
acceleration ;; the constant that controls how much a car speeds up or slows down by if+ E% C5 [- h, l9 M
;; it is to accelerate or decelerate4 I7 H8 T' S7 x- D; K
phase ;; keeps track of the phase) Z1 Y' U$ S2 z. y7 N
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure" X8 ^4 q+ J, ~5 U/ \
current-light ;; the currently selected light
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6 P7 u0 S1 J# Q' S% r" Q' S ;; patch agentsets9 D3 k: T# S9 W6 b- W" C+ L
intersections ;; agentset containing the patches that are intersections& d/ G' X0 O4 m' ?
roads ;; agentset containing the patches that are roads
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5 ^6 T- Z1 N X/ m& n8 `" e! j# A2 fturtles-own
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2 U: `6 j3 \& _; A* k3 R( S0 v speed ;; the speed of the turtle7 `" n0 t; D. t2 H" q
up-car? ;; true if the turtle moves downwards and false if it moves to the right2 O( G' E! u/ E6 n; `! h- S! E
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own9 q0 O$ x; T5 ]7 x" G% X- ~
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intersection? ;; true if the patch is at the intersection of two roads
7 |/ p9 V& v$ _/ L. H/ G green-light-up? ;; true if the green light is above the intersection. otherwise, false./ V7 \2 F8 J5 B4 \
;; false for a non-intersection patches.
1 X8 z, |5 L" _; ] my-row ;; the row of the intersection counting from the upper left corner of the) M3 g# x3 P7 V2 G$ m+ U
;; world. -1 for non-intersection patches.# _. h" K; H" a8 E1 Z) y2 ^6 a/ P. a
my-column ;; the column of the intersection counting from the upper left corner of the! B t2 Q3 r L( u4 ]- Q- I1 `9 U4 W
;; world. -1 for non-intersection patches.
* [" }; o8 ~/ ~4 ~1 K my-phase ;; the phase for the intersection. -1 for non-intersection patches.$ z% G9 U1 f. X( {: ?) y4 E+ G- Y
auto? ;; whether or not this intersection will switch automatically.
& ], i$ S) U/ \0 s* A$ s ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
, Q) K# h/ D8 S7 x" E4 H4 M- P* n;; Setup Procedures ;;! Q; t; m; A ~* r
;;;;;;;;;;;;;;;;;;;;;;
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5 H9 n' B" G- u- T% l$ b6 d;; Initialize the display by giving the global and patch variables initial values.
4 U" i j" M( r0 M% N2 A& R;; Create num-cars of turtles if there are enough road patches for one turtle to
/ P. z2 d0 Y. e, r( O6 I;; be created per road patch. Set up the plots.
! P! O x$ ]: S2 H/ zto setup
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setup-globals
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4 I3 q8 K6 w6 I! D ;; First we ask the patches to draw themselves and set up a few variables
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make-current one-of intersections
5 M# t7 S( L$ e. o* G label-current$ e1 Z9 @& h0 V
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set-default-shape turtles "car"
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9 r# v- ~) E: ?% ~8 O if (num-cars > count roads)1 U/ A" P: e+ Z/ X
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user-message (word "There are too many cars for the amount of ": s$ _. I, J- k+ q( J+ i
"road. Either increase the amount of roads "
B' S5 e1 m: ]: S2 t' F "by increasing the GRID-SIZE-X or "" ~( _3 s- D% w ?9 n
"GRID-SIZE-Y sliders, or decrease the "
' Z1 T( Y$ ?# W+ r1 ` "number of cars by lowering the NUMBER slider.\n"
( k. \- D' F; d* t5 M2 C& H q "The setup has stopped.")! }$ A$ s& ~- Y, ]+ Q( @0 i
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color# G# B* @( C/ d4 q9 S
crt num-cars
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setup-cars! g2 a1 O" N6 u
set-car-color
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;; give the turtles an initial speed% M5 W8 p0 r+ o3 J7 I# Z
ask turtles [ set-car-speed ]8 {" V- E' b3 @ T- X& F
8 s; A, r# P" P' t, n& o reset-ticks- R' t! {1 p6 \( L, R$ v D- D
end
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;; Initialize the global variables to appropriate values" J }0 t ~+ B5 E& b! p6 j
to setup-globals
& o* F! P8 _0 O3 W6 c set current-light nobody ;; just for now, since there are no lights yet" m4 |8 M6 d% h9 d" y; v
set phase 0: E9 M1 V* ]% p" ~( N. ^1 C0 |& k1 s
set num-cars-stopped 0
1 d' N' ~3 n& [: @% q6 u set grid-x-inc world-width / grid-size-x5 ~) F. n( Q- S2 ^! J4 m n3 B( a( h
set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
6 A0 L% T& b5 d' F Z set acceleration 0.099* n" a& N% n, O2 J# y3 d
end
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" V" Q+ H% R, w6 K;; Make the patches have appropriate colors, set up the roads and intersections agentsets,8 g) i* A2 r& @, p3 l/ Z. E
;; and initialize the traffic lights to one setting
) n1 T% j! Y( r! j$ c# Pto setup-patches. r# U) ~1 C- @3 N; o
;; initialize the patch-owned variables and color the patches to a base-color* A& e' d) z% M5 B; \ ]0 u7 j( m
ask patches
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{" b, |1 P7 E) L% D4 [ set intersection? false4 Y, W; Q" z/ f0 h
set auto? false0 `/ q0 X8 K2 t
set green-light-up? true
9 S3 E. }, n$ n- L- W set my-row -1
4 o7 f5 _4 o6 `( h6 v0 o+ H set my-column -1
+ B% S# o" T( B/ f# U* D5 l set my-phase -1
: G, L. ?2 ]* g% P1 V4 H8 T6 b. O set pcolor brown + 3- y/ E, e5 W# L: z8 G4 N
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' ?6 d5 i) Z% [ ;; initialize the global variables that hold patch agentsets. [/ t, F) d( k" G2 G
set roads patches with
; S0 Q4 J, }' G; Y f; ^ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or: }; w$ Q# t G8 t8 z0 I) Y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ | R+ v5 k: N7 a- `! D
set intersections roads with
% a* @. }7 r9 P [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
| n) I( |' {" M6 z- z) t (floor((pycor + max-pycor) mod grid-y-inc) = 0)]: S8 X @' g) S7 S: w ?# {. H
2 ?" H4 w- P j3 R$ D: f7 f ask roads [ set pcolor white ]" R1 |7 I3 d& s* B! M' L3 D
setup-intersections
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" w- O: N: }" t! C其中定义道路的句子,如下所示,是什么意思啊?1 d; y+ U8 {2 Q7 n% L- a- O
set roads patches with, M8 W6 q' u- J1 t
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or5 D/ G4 O& z9 r4 p
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ f9 B: e8 G4 d( I6 s" k- Q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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