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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。& ~% T- M; j, H8 g/ C
netlogo自带的social science--traffic grid这一例子当中,
0 K9 X6 K: Z6 T, K: P( h+ tglobals$ `" S4 I: z- T3 w' z3 ?: b$ Y
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grid-x-inc ;; the amount of patches in between two roads in the x direction
I" U2 l- s* _+ u1 [ grid-y-inc ;; the amount of patches in between two roads in the y direction: S9 _- F5 X% f$ a# J$ y1 K: [) O
acceleration ;; the constant that controls how much a car speeds up or slows down by if* `( n, }% b1 [) n7 q0 E7 c" `8 y
;; it is to accelerate or decelerate
+ v* }6 o5 {4 ] phase ;; keeps track of the phase
9 b* n! `$ t2 [1 k- V# H% a; ? num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure& E! R/ Z5 }4 w- m! @
current-light ;; the currently selected light
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$ `* V0 W4 e- O& W9 H+ W ;; patch agentsets
9 ^( k1 P9 b4 U- t intersections ;; agentset containing the patches that are intersections
7 S% v9 t3 ]0 t: d! G$ @- G; X roads ;; agentset containing the patches that are roads: X; i/ n+ u1 F$ R
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1 S6 X7 d' y X2 A: c7 Zturtles-own, `, a4 Y% h, \/ h5 |+ J
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speed ;; the speed of the turtle
; s; F9 H# \3 h up-car? ;; true if the turtle moves downwards and false if it moves to the right
( r9 T* Q3 m- }4 c: g% Y* S! D wait-time ;; the amount of time since the last time a turtle has moved7 Z8 ^* { ?$ C* q! L, z( ]
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5 u1 p/ x6 a1 V7 H! Upatches-own
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) [! s L* i! G5 J7 S2 J9 r intersection? ;; true if the patch is at the intersection of two roads: N0 ` o7 I' M3 ?1 t' v5 k
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
4 y3 J( y. z9 H g0 X: r$ r ;; false for a non-intersection patches.; k, g8 {$ {9 \; M- J+ K: h! ]
my-row ;; the row of the intersection counting from the upper left corner of the& Z& s$ e' U, R4 I u
;; world. -1 for non-intersection patches.. w+ j1 I0 r# l3 \
my-column ;; the column of the intersection counting from the upper left corner of the
4 b, D( I# L) g* d6 Q- m) K ;; world. -1 for non-intersection patches.
# y9 k9 x6 x9 G0 U' f: m2 I0 y" [ my-phase ;; the phase for the intersection. -1 for non-intersection patches.
: r% u) _ m1 K- t: V. W4 K auto? ;; whether or not this intersection will switch automatically.
) f- h6 [+ f8 m/ ]; ]& L ;; false for non-intersection patches. ?: E, D% A: y4 A
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;;;;;;;;;;;;;;;;;;;;;;
& K0 Q, P. J5 e* o5 T& |& Y$ ^;; Setup Procedures ;;( @7 z# p% N: `: {/ x% T
;;;;;;;;;;;;;;;;;;;;;;: O8 o$ T# q& A6 Z7 l( |# r1 k
3 V& M. \. \' y, V) {! _! z;; Initialize the display by giving the global and patch variables initial values." j' [8 \1 B* F' E9 m2 P
;; Create num-cars of turtles if there are enough road patches for one turtle to
. f$ W$ W9 B( T2 t$ y% K;; be created per road patch. Set up the plots.1 O* @( t# p- m+ ?6 C! U* }9 E9 S
to setup
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setup-globals; S# J' r7 }& x
+ o( p+ A- l7 B1 d* |! q1 ? ;; First we ask the patches to draw themselves and set up a few variables, J- g3 q; P3 W9 M4 |' r6 `
setup-patches' U/ H; [8 h& e3 x3 |, B8 g
make-current one-of intersections6 L/ Q" C7 e) T: m# d* v: P
label-current
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/ k. r) m" t0 a3 N) `6 E, P set-default-shape turtles "car"
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1 ]7 p4 \4 Q9 z if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "- [7 ^' m- S0 g3 X6 |* p
"road. Either increase the amount of roads "
9 b H2 [2 n; R "by increasing the GRID-SIZE-X or "
# B; P: B# ]* S0 A5 d "GRID-SIZE-Y sliders, or decrease the " w. q* _/ b4 d9 v1 d) F
"number of cars by lowering the NUMBER slider.\n"
9 r+ n; F$ r8 N1 F) N4 C8 ]+ R "The setup has stopped.")
* h: ^) f, o2 `7 s1 A/ l: Z stop0 k+ @+ A6 n: y! E0 l
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! Q+ Q$ X; Y1 t) \8 Y0 H: | ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color. x4 r1 D9 [! t! I# Z
crt num-cars8 Z" T/ e# Q3 U& n4 t: r
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setup-cars T, R: P, X A8 t
set-car-color
& X2 N8 v7 s5 m, b- h/ q" | record-data
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;; give the turtles an initial speed
, e! g6 X3 U( t6 T; B- E+ e! w2 q) ~ ask turtles [ set-car-speed ]1 k/ k) b4 \9 w
1 l7 \& r- E0 a reset-ticks% S% d2 }1 J3 {) L9 i, d2 [
end# q: w2 E& y' H" Y* u6 t8 c
( Z5 D5 p9 e0 R7 w5 u3 P' F;; Initialize the global variables to appropriate values
; V- Y4 O1 {5 t% I3 F* S/ B3 u7 ~to setup-globals; d) m9 ^+ ^0 _1 J) s: M7 K
set current-light nobody ;; just for now, since there are no lights yet
/ w* A: n5 p0 V( v6 t( H+ z) e set phase 0
! Q; w, f( M5 N9 L% Y: a, B set num-cars-stopped 0) P" O8 x- e5 I8 S# X0 I2 `
set grid-x-inc world-width / grid-size-x* B. k' J* f+ G1 R# `
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
, x# y9 B3 x5 g( f) j, f set acceleration 0.099
) R7 j7 P* ~; J, d, c6 `end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,1 [; ^( C' ]7 O
;; and initialize the traffic lights to one setting
0 l* y Q+ T. ~: M) ~( Zto setup-patches& C% o. W3 e9 C% M3 u
;; initialize the patch-owned variables and color the patches to a base-color
. i# \ ^* x, f ask patches
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Q6 e* D" L2 b+ S# @( |. e set intersection? false$ M t8 R% R- F! G& C
set auto? false7 ]& k- w! F: U9 w C! E8 J
set green-light-up? true
8 k1 p a0 \2 X! f set my-row -1% q) e6 | \# Y6 ?; h
set my-column -1
9 L9 K2 g' U* [. k set my-phase -1. B9 G4 S( k3 \& i T" G
set pcolor brown + 39 \( z) F7 Q9 L1 @6 k
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;; initialize the global variables that hold patch agentsets7 T, Z0 Q6 [1 h% b
set roads patches with7 v* s' L$ T6 u- E% M
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 Z7 r7 e- R4 `; u3 Q4 \5 V
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; I; h- `! d6 b3 G& c& P, ?; w* j; ] set intersections roads with4 X0 W% ~! K4 Q
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
8 i$ b' I: g% Y6 z' ^3 w (floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ L( D# ^' i# I; ?2 O! y
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ask roads [ set pcolor white ]
( C, H" w5 P2 \; ^: y" o( L setup-intersections t& n8 O- p2 Q. d7 F5 N3 p
end
6 Z- b' s+ Z0 m H6 O其中定义道路的句子,如下所示,是什么意思啊?
8 Z- m7 a* } g1 P ]/ u set roads patches with
) X/ X" `# I; [$ R# Z I K [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ r( k! F, l& k5 Q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]% ]! A- |. B5 c+ ~" P2 c
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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