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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。
. o" \1 P% |. ? \/ _$ L* Wnetlogo自带的social science--traffic grid这一例子当中,
+ A6 h% H; @0 [. Sglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction0 r8 m0 e8 S c1 g) g6 i
grid-y-inc ;; the amount of patches in between two roads in the y direction m9 S0 t b- v( d; {: D
acceleration ;; the constant that controls how much a car speeds up or slows down by if( a5 ]0 g5 ^3 E: B
;; it is to accelerate or decelerate* ]# B* C1 A8 ~) i6 x
phase ;; keeps track of the phase
& l3 ]) U1 i8 X ^1 { num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure( J+ h/ k; n6 m3 r9 ~
current-light ;; the currently selected light' C8 W# `: _0 @& J: C; n- R( T% s _
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;; patch agentsets
0 d$ Y D% [5 c+ V# r& m) p intersections ;; agentset containing the patches that are intersections9 Q6 e( D5 ?% `, A' v3 C
roads ;; agentset containing the patches that are roads3 O6 {$ x! R5 x! u2 l6 U" b
]
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turtles-own, s4 P) A# @& r- [6 ?# k, \5 W
[
; r' h l# h- x6 `0 \3 i- i4 Z speed ;; the speed of the turtle
' B- l2 X+ f0 h4 @8 b# j- g. b( a& }, a up-car? ;; true if the turtle moves downwards and false if it moves to the right! q5 Z' A* p3 X C& V" y
wait-time ;; the amount of time since the last time a turtle has moved$ d; G; Z% f7 i. U) C% _: s% F& a
]
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+ O- i! q$ m; ppatches-own( h0 _* C9 |1 ^6 I" E
[
/ Y& V% t% _) x3 ~2 B intersection? ;; true if the patch is at the intersection of two roads/ F9 M' ?+ g& I- G3 q
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
: G: c. s' P% y" `/ I% Y ;; false for a non-intersection patches.
- K' a: v/ f) L; h" j my-row ;; the row of the intersection counting from the upper left corner of the
+ I! d3 L7 P7 {* |1 _5 A1 x ;; world. -1 for non-intersection patches.
2 [$ O% O% f: i( g my-column ;; the column of the intersection counting from the upper left corner of the
' ?8 `, M6 b4 ]2 z- \ ;; world. -1 for non-intersection patches.
* a3 ^& k% u Y$ X my-phase ;; the phase for the intersection. -1 for non-intersection patches.0 s7 ? W) T5 D: p/ h
auto? ;; whether or not this intersection will switch automatically.
1 \$ W+ `$ y3 }0 z ;; false for non-intersection patches.% X. B2 }, c$ n
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;;;;;;;;;;;;;;;;;;;;;;8 r$ ^( W. f3 Y: i
;; Setup Procedures ;;: C1 b B1 H2 {$ I
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;; Initialize the display by giving the global and patch variables initial values.. A3 p" B6 [" E* m4 B, n# x2 v
;; Create num-cars of turtles if there are enough road patches for one turtle to$ e: M) p! D9 D" P E
;; be created per road patch. Set up the plots.3 s0 {/ l% B& Q$ k; R- @
to setup0 m, ^7 J! G* i9 L/ m
ca
$ H) `$ W) e+ a3 H# S* B setup-globals/ S3 D# o$ M9 K6 y. V0 X
5 b) m2 O- }5 N4 S; j- @ ;; First we ask the patches to draw themselves and set up a few variables
0 Y) C0 F! @- ? q$ c# [ setup-patches
) B$ z9 A4 r1 m: o: m5 t make-current one-of intersections+ r3 U2 b" |( ]- H
label-current
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/ }0 _8 O3 |# Q1 @# {8 U( \ set-default-shape turtles "car"
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if (num-cars > count roads)- d# E: ~+ B |! _1 Q6 k( n% m
[
5 c6 ~, {, x V1 o& D- H' v/ ~ user-message (word "There are too many cars for the amount of "4 r7 f4 W, a9 w r" W
"road. Either increase the amount of roads "; C$ K$ q0 E- y% l5 {
"by increasing the GRID-SIZE-X or "
6 L. v. i0 Y! ` "GRID-SIZE-Y sliders, or decrease the "
" U, S7 f. _) P! m" B. B! J+ K "number of cars by lowering the NUMBER slider.\n"* ~) _- ^2 c. ^) M' y$ J
"The setup has stopped.")& N5 F |1 @, U, V
stop
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- B% a" H3 H$ y2 p9 G7 E* R ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color6 ~: H0 e+ o8 ~ F/ D2 P ?5 P
crt num-cars: F5 \* K2 L3 S3 S9 o6 f, ~+ T
[
7 r v2 e# R6 r" P8 U* _( F setup-cars2 `+ G! T5 T+ p7 j$ |
set-car-color$ u4 Y u% D# k, N" a3 G
record-data
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;; give the turtles an initial speed$ \* K$ a# W# {9 P% T; M+ u5 J/ M/ S
ask turtles [ set-car-speed ]
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reset-ticks
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;; Initialize the global variables to appropriate values; w' |' r2 Z K! G6 k
to setup-globals
W; w) x& v+ E% j+ i set current-light nobody ;; just for now, since there are no lights yet3 s% b/ ?1 B V. l0 l
set phase 0
: W# N* n- T# |+ @" `& }3 G* v set num-cars-stopped 0
7 w2 W \; l9 |+ w9 N% l set grid-x-inc world-width / grid-size-x2 {( a6 M w8 b# c1 V! b6 P
set grid-y-inc world-height / grid-size-y
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2 c$ s3 s' z- _+ T2 w5 @8 y5 l ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary/ m; ~: j9 ^3 _
set acceleration 0.099, Y. |5 H1 D" l8 O
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets," A. k1 m; j6 O% g8 k0 t
;; and initialize the traffic lights to one setting8 |9 d. |' [! L/ J
to setup-patches
- }5 P3 V+ Q" h ;; initialize the patch-owned variables and color the patches to a base-color
$ I$ c9 T+ Z9 g- X ask patches
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0 @( _3 Z+ ]% h: |0 { set intersection? false
5 k0 U; d9 u! z/ y3 A5 ? set auto? false
7 [5 z7 r! r, F7 v set green-light-up? true
" O$ ?/ C$ s9 F1 |& F( n set my-row -1) h8 l P' E4 D7 y
set my-column -19 N/ Z6 c, `4 W
set my-phase -1! m, {* n' Z. y9 e1 T3 Q/ k$ \, Y
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
4 m6 P4 Q0 @2 u% U7 q set roads patches with) p$ O; N) W/ r; A( m
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or+ E" x, i' i" f) |4 P
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 s$ c% [+ b* ~, }) m
set intersections roads with
5 }" g; K5 P: [4 p( E; I, V [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and' K4 o& Y* V8 }" k: q [. H
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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0 h: G D6 e, n+ l2 g, \, B ask roads [ set pcolor white ]' i' X# Q& G7 n8 O P! B3 b
setup-intersections6 G% O, j1 o5 V. ~- v6 w+ y1 D& i# v; c/ m
end
- I6 N' h; F3 r; W2 m+ e! Z) U其中定义道路的句子,如下所示,是什么意思啊?( g/ l, c5 O7 O/ ~6 I3 f# j4 q
set roads patches with
' I* h; c9 R/ H* t1 `3 ` [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
$ m( v" c2 ?+ W% Z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ r5 `# u' q) k% |( z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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