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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。9 f$ C4 k' b; c$ d; o
netlogo自带的social science--traffic grid这一例子当中,5 V- k! Z1 y& e3 e! e8 r
globals8 U# B! k6 b! _0 j
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grid-x-inc ;; the amount of patches in between two roads in the x direction
6 {% }: l" c, W$ a grid-y-inc ;; the amount of patches in between two roads in the y direction- C+ U# O% H/ R \
acceleration ;; the constant that controls how much a car speeds up or slows down by if( V8 a; t( F- V4 D) K N" s" B: U
;; it is to accelerate or decelerate" D* H6 L% f6 ?& a5 v& k
phase ;; keeps track of the phase
% F/ Z0 Q- i$ D0 l( o7 y0 c num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure. t6 C* j5 p6 x( P+ V2 s
current-light ;; the currently selected light! k$ x3 {! ~5 n* h8 v* b
# [8 ^% G: s' C3 T ;; patch agentsets' [* Z6 t# V2 H0 V
intersections ;; agentset containing the patches that are intersections: F) a, x- o9 Q1 H7 e
roads ;; agentset containing the patches that are roads) ?& Q4 d' c1 k7 a3 C/ V
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6 f2 _& n- J1 Z# j# c1 ^7 iturtles-own
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4 B9 ]5 O/ g8 U, o' l2 N speed ;; the speed of the turtle
, n! Q: @7 ~/ T! F2 T7 S' o3 S up-car? ;; true if the turtle moves downwards and false if it moves to the right
8 j* b; H+ ?) P+ K wait-time ;; the amount of time since the last time a turtle has moved
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) S* f% k' [# J$ [ E+ xpatches-own
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" R. Q/ V7 M1 L4 G4 C) o1 _ intersection? ;; true if the patch is at the intersection of two roads7 a2 L6 F/ j! `& H
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
, x+ u% q: A V% [! m ;; false for a non-intersection patches.
& @0 r) t: I4 K0 I! d% ]8 X' s my-row ;; the row of the intersection counting from the upper left corner of the# `0 A; Y% p6 j& T# t4 p& t
;; world. -1 for non-intersection patches., D7 \, h$ Q4 C4 j* M
my-column ;; the column of the intersection counting from the upper left corner of the8 R0 f/ c0 l u: v
;; world. -1 for non-intersection patches.
5 z2 ~# e9 |1 V) ]# H: u8 |' X my-phase ;; the phase for the intersection. -1 for non-intersection patches.
+ p- P R8 [1 u7 ~9 L6 K4 x auto? ;; whether or not this intersection will switch automatically." o% o! @8 K3 H- y" C# I4 O
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
2 W, e9 }7 h. a6 \# _, h4 q5 R" v;; Setup Procedures ;;" ]2 u7 t2 g) k5 I2 L; q
;;;;;;;;;;;;;;;;;;;;;;$ G2 {3 a- G: M6 o" R" t) }
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;; Initialize the display by giving the global and patch variables initial values.
2 S% {8 j; N5 U" r9 L4 D2 b; l$ j;; Create num-cars of turtles if there are enough road patches for one turtle to+ a! o5 a; h7 _4 F) k* v0 C' z
;; be created per road patch. Set up the plots.
7 F! F9 @* ]6 M# K, \$ ~$ ] Mto setup( {$ Y* t( ^5 Y; c7 W! g4 a5 ?3 @( [" X
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setup-globals
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6 J7 ?. |4 i! c; I ;; First we ask the patches to draw themselves and set up a few variables
P; S3 r) ^2 M! `1 i; G O4 K. v setup-patches2 O% C$ ~2 X2 w$ C4 |9 r8 Q: b8 R2 p- b( Q
make-current one-of intersections7 v7 K9 L; A' d8 x! I8 Y+ o; m( a2 o
label-current% c6 S4 q' G# M4 n+ V, |$ e1 i0 L3 {
2 I7 D% D5 Q9 \0 K' _/ U1 E: _# I/ A set-default-shape turtles "car"
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if (num-cars > count roads)5 L1 A Q8 P( Z( E
[
& c \: O/ K0 g0 U. b user-message (word "There are too many cars for the amount of "
) o5 N/ f# c- K' y' h. ~1 `/ L "road. Either increase the amount of roads "
) x- j+ F) y+ x) k "by increasing the GRID-SIZE-X or "8 X k0 M) j O, C- w- E" ]3 Q
"GRID-SIZE-Y sliders, or decrease the " M" H# K9 {' Y
"number of cars by lowering the NUMBER slider.\n"
* E2 v P" i" s9 c5 s, ] "The setup has stopped.")5 V1 Z) F, `6 D6 g6 a6 Z
stop, U2 h, C' X6 y: M+ I/ `
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- o# q* B @4 U# b" I$ H9 @ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color8 T7 _/ `$ V( k+ X
crt num-cars
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4 o5 R* r' D5 n( h7 U0 l. S setup-cars* |, g4 ~; _% L1 s' n# u
set-car-color( L5 H" A+ | w* [$ H
record-data5 S2 _8 w+ i5 L
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;; give the turtles an initial speed
) [, g/ d1 |5 r y" l ask turtles [ set-car-speed ]
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reset-ticks2 F U3 c3 g: t; Z2 b8 f' j
end( a f+ [" P2 B$ R
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;; Initialize the global variables to appropriate values
3 l: z8 h' Y! U) zto setup-globals
# g# u3 ^, M5 d/ G set current-light nobody ;; just for now, since there are no lights yet6 F1 R |7 E) @& H) ], o
set phase 0( L, |- E! o: U
set num-cars-stopped 0 U- Y n# X8 R/ _
set grid-x-inc world-width / grid-size-x( {9 f) {$ D; _+ \* s! `8 H5 Z: A
set grid-y-inc world-height / grid-size-y1 U% P) E4 s) k$ G' n3 d& k
0 ^$ e$ ^, x- D; e% |' ] ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
' Q- D& m8 H5 y$ a% s2 ~6 J# h set acceleration 0.0994 Z- `6 e0 j, L
end
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1 L% u' T5 y8 v, ]! N. I7 S; B;; Make the patches have appropriate colors, set up the roads and intersections agentsets,. D0 ^2 y9 u* n! G
;; and initialize the traffic lights to one setting
4 n: o6 a6 R9 A0 l7 Nto setup-patches6 o# P' e: \$ ?
;; initialize the patch-owned variables and color the patches to a base-color
d) r9 z( m: l ask patches9 c, v9 `- d. l$ f x! M
[
5 w0 P2 K& H, B# s& h0 P) D4 k, d: n- w set intersection? false6 r' I0 E0 E& G/ z$ Y
set auto? false" L6 V! L/ Q) i5 v8 p( ?
set green-light-up? true
8 }1 K0 e1 L- F) o set my-row -1
+ q! h/ }/ q; f# i3 T" ] set my-column -1 U& L8 C% P! N) j! ]8 W
set my-phase -11 U' R; A) _" F. ~' N; D
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
; S F" o* s; b* f- s/ J set roads patches with
* m7 {- }; o: N' L B [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
0 ^1 z, m g4 \+ k (floor((pycor + max-pycor) mod grid-y-inc) = 0)]; f; ?: ~5 a) | @3 t* J
set intersections roads with
- g7 j: a* ]6 z) f. b [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
( \# z) V9 Q- t+ m3 T4 b8 y1 j (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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" o j6 ^- ?. V+ { ask roads [ set pcolor white ]
2 q% B0 k0 J! K! R; g setup-intersections2 q0 N# X# v, O. e
end
7 Q% m4 N" b* i" w/ N# a其中定义道路的句子,如下所示,是什么意思啊?( X1 G# ^; L$ h5 I9 v
set roads patches with
9 o9 Q' \: k0 g% u4 K [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or$ v- ?! v1 q$ r4 g9 E
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* L5 f6 P; ?9 ~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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