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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。& P3 R! M3 a& b. | N7 q6 b
netlogo自带的social science--traffic grid这一例子当中,7 o9 Y/ C1 T: x8 y
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
& t' e$ ^( d% k grid-y-inc ;; the amount of patches in between two roads in the y direction0 c/ N8 w0 m) I2 ~+ p ~
acceleration ;; the constant that controls how much a car speeds up or slows down by if
& D/ [9 Q- A: a5 Z2 h4 c ;; it is to accelerate or decelerate! G: s. r7 m) b, p! ^9 \
phase ;; keeps track of the phase. a( f+ y4 T2 T+ D. h& I
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure& y0 w! Q: \, h8 O4 |
current-light ;; the currently selected light$ P* S7 d9 o$ r8 V3 x
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;; patch agentsets0 R( `' v" f% g( j' l% i. `
intersections ;; agentset containing the patches that are intersections# [6 X U$ N4 W" K
roads ;; agentset containing the patches that are roads$ V( o' A @3 C: w
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$ q* d7 Q0 H5 u2 R8 h+ p7 ? g* {turtles-own. n! I0 T- ~* ~( q, X" ~" k
[
! K1 Q- w! q8 w speed ;; the speed of the turtle
- v# T- y" T- B5 u up-car? ;; true if the turtle moves downwards and false if it moves to the right$ q F& U+ |$ n' [4 P1 e! v
wait-time ;; the amount of time since the last time a turtle has moved6 H9 [+ H$ _6 ]& L- n l
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patches-own( j8 [/ J( }! F. j ]% z3 A/ p
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intersection? ;; true if the patch is at the intersection of two roads
5 o! y7 n9 _- v0 v8 }9 s6 Y green-light-up? ;; true if the green light is above the intersection. otherwise, false.
* a3 p' C- H$ `) w' P9 G ;; false for a non-intersection patches.
& j- U8 s8 [. v6 }1 c% \ my-row ;; the row of the intersection counting from the upper left corner of the
v; w% S% {0 u( @0 {. q ;; world. -1 for non-intersection patches.1 G$ {0 x/ b# [6 B+ O
my-column ;; the column of the intersection counting from the upper left corner of the( m4 Y2 |! _- Z6 L) v, f: k
;; world. -1 for non-intersection patches.7 R5 O) t1 Q' g, A# @
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
! z1 G- h& ~5 i1 e. Q5 x auto? ;; whether or not this intersection will switch automatically.
0 x' j \9 ]7 ?. T ;; false for non-intersection patches. K) _% {! s3 Y
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;;;;;;;;;;;;;;;;;;;;;;5 E9 ~+ y+ \! _
;; Setup Procedures ;;
( e7 E) ?* _5 N2 e4 d/ m7 [;;;;;;;;;;;;;;;;;;;;;;
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$ w! A) v+ ?5 }6 R$ `5 i;; Initialize the display by giving the global and patch variables initial values.5 H$ c4 u; Z4 d: {1 V& Q/ \
;; Create num-cars of turtles if there are enough road patches for one turtle to
# ]' `9 Q1 O; w/ ?% T;; be created per road patch. Set up the plots.
* J3 a* V0 i; o9 t7 Qto setup
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setup-globals
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i+ N1 {/ g0 G$ B8 k ;; First we ask the patches to draw themselves and set up a few variables1 Z2 I: c" Y8 G& |6 E- Y) z
setup-patches
# _! ~& l4 W* u0 m/ O- j make-current one-of intersections/ C! S l0 z' M& p$ M# C
label-current
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set-default-shape turtles "car"
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- ~5 G0 L, _+ s( ~ if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
- ?$ c3 m2 X! q2 J2 N/ [0 X "road. Either increase the amount of roads "3 L+ C- B+ e }8 j
"by increasing the GRID-SIZE-X or "" ^) \! X# A) r: g9 n, z
"GRID-SIZE-Y sliders, or decrease the "* C% D3 _: {/ \1 D$ V; d* U+ N
"number of cars by lowering the NUMBER slider.\n"
6 @8 J: N" E' l+ U* @: N+ M: A "The setup has stopped.")
8 E. j! M2 v+ e0 w2 C$ J( y' D) Q stop
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+ a1 R7 J# @2 l$ M% `& a+ @" ^ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color6 X8 V, A8 R5 G1 [# l
crt num-cars
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, u- t( ^9 x3 P9 Q2 _8 K setup-cars5 ~$ K7 d& }9 ?+ |% O
set-car-color8 \- K2 a( k& c
record-data. G. I" z( f$ d" }; C1 b
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2 Y3 P4 h! y/ }- O/ g9 Q ;; give the turtles an initial speed
! l* q; _' I& [: e ask turtles [ set-car-speed ], k& ^6 l$ j0 ?3 ?) h+ E" q: q
; u4 X( C0 ?& E2 e reset-ticks
% p2 w- Z9 r9 @: ~3 b# ~+ ]end
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;; Initialize the global variables to appropriate values3 @5 z* E7 h* J) c
to setup-globals* {3 ^$ u- t( u2 \7 e2 a
set current-light nobody ;; just for now, since there are no lights yet. f7 s$ E* G% [ |3 y
set phase 0, j! ^- J& v5 T- f, Y a( S
set num-cars-stopped 03 B1 b0 f3 A" F3 C" x4 x
set grid-x-inc world-width / grid-size-x0 o2 B# a7 C$ s/ m3 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 n" n4 \( i" g
set acceleration 0.099
$ l$ i7 H* |. @* [4 send
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7 a5 j5 K3 I/ Z- r' P) s( K7 p, A;; Make the patches have appropriate colors, set up the roads and intersections agentsets,) e5 \2 F8 F- F& g0 r) U$ L
;; and initialize the traffic lights to one setting
" ?1 N- I+ C1 L2 Yto setup-patches; c N+ [" h! T- |. S* I+ i
;; initialize the patch-owned variables and color the patches to a base-color
/ s D/ j" I9 J4 o$ G& h ask patches
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7 |4 u. l; ]' M/ B0 t set intersection? false$ \: W% k9 t0 c9 [/ H3 u9 C
set auto? false3 A5 _' {& g3 b! T r$ G
set green-light-up? true: E$ ^4 }+ o9 N+ l
set my-row -10 h4 v5 e2 Z9 o
set my-column -1
6 S! `# B$ }0 T7 ^; y4 ~/ Y; c0 G1 R set my-phase -14 T- `; N6 J2 }( p
set pcolor brown + 3
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- F+ ^4 b/ Y; V5 @0 v ;; initialize the global variables that hold patch agentsets5 |7 z2 p% `6 O9 w7 n2 M1 z
set roads patches with* B2 X$ `# C7 Y
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
4 h( n9 y( f& [/ w! E (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 z2 F# n" ?) e% J3 J set intersections roads with
5 O/ `$ n$ l8 D% Q: p3 j6 l% m3 r [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and/ w9 x2 d6 e, v q2 w8 y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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+ A" F6 n2 e% w/ g8 Z ask roads [ set pcolor white ]8 e/ o* e! ] d0 U. Q' T
setup-intersections
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4 e2 P8 w/ L! P6 i! b2 |其中定义道路的句子,如下所示,是什么意思啊?. q- B0 q) H1 `! `8 I
set roads patches with0 t. [; q, J2 B+ a+ J
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
2 W' y9 a3 a, N$ I7 W) x (floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ N) {5 u$ q4 S5 G& T; I
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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