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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。# O0 @6 M, j2 a3 {* [
netlogo自带的social science--traffic grid这一例子当中,) u( O) B+ H" X i$ \
globals
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2 [4 F% U: U* g8 w grid-x-inc ;; the amount of patches in between two roads in the x direction! n1 }/ g3 X: H! `& {9 z0 t7 X
grid-y-inc ;; the amount of patches in between two roads in the y direction+ a: {7 t2 r2 b% J6 a
acceleration ;; the constant that controls how much a car speeds up or slows down by if, @" v t" E! O2 F, K
;; it is to accelerate or decelerate; J! w( R! t; V% f f% Q
phase ;; keeps track of the phase
/ u. b- W8 s6 C num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure1 d. V2 f. {- O# I. f
current-light ;; the currently selected light! i1 l( b* p$ C1 L) A: m; L
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;; patch agentsets
! A8 D" P% o% k: v0 U intersections ;; agentset containing the patches that are intersections ^; W' G1 ]7 h' |
roads ;; agentset containing the patches that are roads- V8 s' m S7 `+ |9 r7 D# x8 o
]
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5 ]& G/ U4 z9 J' M! Lturtles-own
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0 E0 r6 x% o$ J o/ z speed ;; the speed of the turtle9 @3 t2 K* U0 Y( J+ v. I
up-car? ;; true if the turtle moves downwards and false if it moves to the right @# [1 D9 z5 N6 P
wait-time ;; the amount of time since the last time a turtle has moved
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" d2 J6 h" _, E9 d9 t0 gpatches-own
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intersection? ;; true if the patch is at the intersection of two roads8 B, `/ z- x9 P/ Y" a' }7 ~
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
6 ^ N8 W$ k% S0 n/ R ;; false for a non-intersection patches.8 t* Q: V/ E( o' K5 }% {7 a% ]% ]
my-row ;; the row of the intersection counting from the upper left corner of the
/ g# l# t) A* |& H' w+ L) I& D ;; world. -1 for non-intersection patches.
) } D; L1 r* ]% U& M/ M1 b my-column ;; the column of the intersection counting from the upper left corner of the
* Y- F( Z2 W: K4 Z ;; world. -1 for non-intersection patches.
# W# E# P8 K' x! r my-phase ;; the phase for the intersection. -1 for non-intersection patches.
1 ^ {, R# V7 M* o auto? ;; whether or not this intersection will switch automatically.% j+ w! I+ M+ |- B
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;& ^/ ]' J2 V: g3 W5 Q
;; Setup Procedures ;;
8 [ N: E2 \1 x# I" W;;;;;;;;;;;;;;;;;;;;;;
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% Y0 c; ~9 I9 A* G- {& a! w;; Initialize the display by giving the global and patch variables initial values.
, `* I9 }9 a8 K7 ^6 |* \;; Create num-cars of turtles if there are enough road patches for one turtle to
: }0 d t2 @2 ?. e8 n5 L;; be created per road patch. Set up the plots.
4 J1 o0 A; e& A( u1 `to setup: F( Y# R/ w7 r" W8 }) d9 g9 g
ca
* W8 f2 Q) z5 g( J( ^1 E5 T& Q setup-globals9 i- m6 {8 T, e, }4 E) Y7 K# d! x
0 |( m y$ J0 v% w! ?, Y ;; First we ask the patches to draw themselves and set up a few variables
& J9 M* y3 M* ]/ G8 E9 }& l$ q3 ` setup-patches6 N1 `6 ?9 N" @% ^# m
make-current one-of intersections: ?. V' h# O {) h$ p/ t
label-current
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% f4 ?- j( k) c set-default-shape turtles "car"
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "* F. N0 Z: u% s0 p2 J( w0 w
"road. Either increase the amount of roads "4 T" g4 ~( _6 ^2 f8 X! H" u4 o
"by increasing the GRID-SIZE-X or ": e. C4 e! V/ U6 s9 c+ A2 F
"GRID-SIZE-Y sliders, or decrease the "- J$ ^% O4 U0 b1 x2 p: `6 n
"number of cars by lowering the NUMBER slider.\n"
7 C! S" f- p1 J! d# b "The setup has stopped.")+ C- k8 n" ~$ |
stop% ~6 B/ |* U @. \/ I
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; V9 Q: i1 f2 k1 ^5 G ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color, D J( O: ^% x; g; Z+ u! v# J+ ^ F& |
crt num-cars
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setup-cars
' _: c/ u1 I% J9 C0 r set-car-color
) t) n' C) C5 L) f. M: D record-data
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5 H1 j- w# R- I5 [4 ] ;; give the turtles an initial speed
4 B8 d& \4 F" x1 h: p. k0 ? ask turtles [ set-car-speed ]) V- |0 V. l: o. H6 o
9 h# X6 E% [, z: O! _: O( U reset-ticks% o- d6 K2 |/ U. a
end
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- b+ V" I* g3 X8 y;; Initialize the global variables to appropriate values! _# O) P c) `
to setup-globals- t8 s8 O5 E: o1 ?
set current-light nobody ;; just for now, since there are no lights yet. V! v; F. r3 x9 d
set phase 0' X8 {0 l0 O. Z/ a5 x* @2 \1 h
set num-cars-stopped 0
3 v) A3 D2 P2 j* h set grid-x-inc world-width / grid-size-x3 C% w4 e4 Q" z( v$ T3 O |
set grid-y-inc world-height / grid-size-y
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. l# `- N4 [' b ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
1 H5 D5 E- X' |2 O set acceleration 0.099& M; q' W8 L' m
end
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5 ?0 w& o/ Q* V;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
# R1 b+ w6 s9 J( E0 O |2 [, v;; and initialize the traffic lights to one setting$ h4 ?- b7 P) {" K- n
to setup-patches5 n4 u; T9 P7 k6 L
;; initialize the patch-owned variables and color the patches to a base-color
+ u5 ?7 A( a( n5 W" }( s7 y ask patches
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set intersection? false
; B8 c( |" r# ~, v/ k set auto? false$ K+ ?( ]4 ^% {
set green-light-up? true
| o( |0 R e$ S* \ set my-row -1
5 a f& \9 k" \# |" [ set my-column -1) u2 s, T1 x( G9 u- @, K m9 j; o
set my-phase -1
. Y6 h: h, ~! ?& Y* l! m% w/ L set pcolor brown + 3
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9 b# G- c; o* B& N9 f, F/ S+ k ;; initialize the global variables that hold patch agentsets) P5 Y$ t5 j3 z0 R) L$ d9 E
set roads patches with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 u# C* d5 n3 I7 o, @
set intersections roads with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]: ]3 }5 }: g; w$ S: y
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ask roads [ set pcolor white ]* T- Y7 G" j; `
setup-intersections. }# S$ P6 x3 A
end( A; k3 _+ j$ l1 C) t% \% v) W, e( V
其中定义道路的句子,如下所示,是什么意思啊?
6 L, C) N. X. G5 d set roads patches with, h- X4 F$ A* [
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' G" @6 R6 r- n& [% I& w' _/ e
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) a5 w! A/ w% O0 `) E' {% R# d: q4 K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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