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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。' m+ R' ]6 x' K9 M5 Q8 M r5 b" r8 W
netlogo自带的social science--traffic grid这一例子当中,
, D% U/ t& p8 i+ h) gglobals( i% g( J8 ]4 s9 ^$ }
[
% f. c: @, s$ U: l. ^0 L S# Z8 n grid-x-inc ;; the amount of patches in between two roads in the x direction9 O [( i( q8 l( m K
grid-y-inc ;; the amount of patches in between two roads in the y direction
* k: ] L* @) t4 U+ Q acceleration ;; the constant that controls how much a car speeds up or slows down by if- c& c0 ~# v% w( \; R
;; it is to accelerate or decelerate
1 f9 c6 I0 S' l phase ;; keeps track of the phase: b% n/ V Y5 o7 k Q
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
, }. j0 j& J9 B S* P& |/ S. H, F6 N current-light ;; the currently selected light+ P1 }) W) {% g. Q
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;; patch agentsets
: |! K0 Z- {! r1 q intersections ;; agentset containing the patches that are intersections1 v5 W& t7 s: `' ]1 j j9 m- S
roads ;; agentset containing the patches that are roads
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. c* [- G8 v; \1 r4 _ G% g, J5 i/ g- Nturtles-own4 x( ]2 k2 e5 q/ \0 D6 q& J
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speed ;; the speed of the turtle
, r% }6 g# Q5 U up-car? ;; true if the turtle moves downwards and false if it moves to the right
( X2 X+ B1 e1 n& B0 ^7 l wait-time ;; the amount of time since the last time a turtle has moved4 [6 Z% R% z! m$ T
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5 ?- s. ]. W7 ^; N+ ?; n: U! w3 gpatches-own
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intersection? ;; true if the patch is at the intersection of two roads! T8 S9 n3 D/ }( f; v5 [, @: L
green-light-up? ;; true if the green light is above the intersection. otherwise, false., u1 x r K/ Q. R( o( Y( p
;; false for a non-intersection patches.
, ? _& }/ g, O# @+ O; |' @ my-row ;; the row of the intersection counting from the upper left corner of the) }: G2 y( n( |& C; E
;; world. -1 for non-intersection patches.$ |( ^" i5 J) U R
my-column ;; the column of the intersection counting from the upper left corner of the$ ~/ C8 G2 D* v5 J# K+ T
;; world. -1 for non-intersection patches.
9 N3 q9 V; V- k. E8 x5 n1 ]; r my-phase ;; the phase for the intersection. -1 for non-intersection patches.
. }/ A% y5 H% Z6 v Q9 P auto? ;; whether or not this intersection will switch automatically.
/ l! H# r% b& U4 b6 p$ j! `1 c) X ;; false for non-intersection patches.
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9 l8 U% j7 E* J) \$ Q- j;;;;;;;;;;;;;;;;;;;;;;
) n. ]' A7 X, ]! |3 N! l;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
5 g$ Z& R% H1 x6 \ H. S. F;; Create num-cars of turtles if there are enough road patches for one turtle to% G) s* x$ y; j4 }: E& F" |4 t
;; be created per road patch. Set up the plots.
) O' |. [ ]" t |to setup2 h l$ [7 u' X
ca
5 J( x) D+ i6 h$ @9 x& S- v setup-globals- y. h" G9 c* D! J- u) O
' ?0 S% ]% w$ E5 E; h: \, D ;; First we ask the patches to draw themselves and set up a few variables& a2 N9 ~. u; |) G* S- |- a! u" T
setup-patches
5 n& f ^3 ~ Z1 l4 \ make-current one-of intersections: X5 }$ V U# F2 t" x
label-current7 _7 y5 _8 ?* h @4 ]4 k4 K
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set-default-shape turtles "car"+ q: [* ^% D( q! q' x- x
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if (num-cars > count roads)+ |8 C2 V, N- [, Y! [% v9 o
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user-message (word "There are too many cars for the amount of "+ n' E6 T' T" K8 Z
"road. Either increase the amount of roads "( p, u: `" ]% {
"by increasing the GRID-SIZE-X or ", g7 i* l- c+ T B: ~
"GRID-SIZE-Y sliders, or decrease the "
1 Y5 \+ u6 {) o7 w2 H( D& P "number of cars by lowering the NUMBER slider.\n"
, t! _! G) z/ w- q# F$ B, E1 r6 U "The setup has stopped.")$ C: S1 S% d# i) V7 r8 p; j
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color3 i/ e( R7 t' |, |
crt num-cars
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. m+ |& D0 O3 a/ V; e setup-cars
& j) E* n2 b$ N# b$ ~) I: f set-car-color
7 x8 T( H4 T0 v1 Z$ w record-data
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^; L4 U% X; e. j1 Z& a ;; give the turtles an initial speed! u5 k4 B' E& R# j1 h
ask turtles [ set-car-speed ]6 i! `# B! Z2 _4 A3 l
0 O- @7 p6 E, I$ } reset-ticks: X9 U: }- L. f$ Z! L3 w
end
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* t# y e+ O5 U! }" H2 J;; Initialize the global variables to appropriate values! d W9 w" U H# o7 Q& n1 y
to setup-globals
- p& i% o- ]& A" x( P set current-light nobody ;; just for now, since there are no lights yet& s( D* {( @( y9 k
set phase 0
6 b7 @4 P9 i0 L* r! h set num-cars-stopped 0
9 j3 r( Q* L, R( B0 s set grid-x-inc world-width / grid-size-x4 z% [, j/ r+ ~( o
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- D& w! d. |9 ~8 D& E
set acceleration 0.099
/ q+ @2 u) n% C1 `" Iend
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% x0 O) X3 @ l1 R6 M;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
4 g3 x* r- B- M/ U0 W;; and initialize the traffic lights to one setting
2 k4 z4 l* @7 G- l5 eto setup-patches; G4 M$ E$ `" h' f. W2 [
;; initialize the patch-owned variables and color the patches to a base-color4 F6 A' z8 B6 P: C- D3 \
ask patches
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# G, U6 Y( c6 N set intersection? false9 }. _- F; W/ l2 H& E9 y6 E3 ^3 Z3 o
set auto? false$ p2 V- T/ Y* c7 c: K0 u+ h) c/ N
set green-light-up? true, \. O- a* x o
set my-row -1
0 i. ?( Y* `) W) p) ` set my-column -1' s! T+ g, n, w# K9 l* [
set my-phase -13 v7 D8 m- m9 Q4 \; ^8 A( x
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
4 n9 I! T% _4 {) h# D set roads patches with6 k$ [* H6 t- E- |
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' g+ q8 G5 P1 l1 O, V& n
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 o4 ]" z+ _! j
set intersections roads with9 d; r+ v) Q0 @& h" z
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
& s" N$ v- U0 k (floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 \: Y1 X0 v; K8 y
, [' G9 h+ i- u" \- E ask roads [ set pcolor white ]# x) e/ `: c% A, A
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?4 D) `) [' ^" S% d/ }& y4 J$ U, B
set roads patches with; p' e% a" ^$ M6 L/ k/ t
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
4 U; ~3 r4 Y1 q2 p (floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 j! v- L5 u/ ]+ x4 ~! Y" P5 j& Y
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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