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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。
) Q, d& o% q0 i2 q4 wnetlogo自带的social science--traffic grid这一例子当中,& P: J% ^2 \; J& T# `# W
globals; E3 H' k, @% ]* |7 W
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& N9 y3 \" l7 `# ?6 f grid-x-inc ;; the amount of patches in between two roads in the x direction0 ?" K! m' {% F
grid-y-inc ;; the amount of patches in between two roads in the y direction
4 u, l3 e! v' N acceleration ;; the constant that controls how much a car speeds up or slows down by if
4 x2 j {1 I! v7 M, r ;; it is to accelerate or decelerate S: t& H- ~, D$ p% X
phase ;; keeps track of the phase
7 H0 F# \7 j& A9 L num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure* a! `' O7 x! `# o
current-light ;; the currently selected light
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;; patch agentsets `# X- e* C7 h* ^- B1 u0 A, a
intersections ;; agentset containing the patches that are intersections% \! V6 n5 l0 G; k* d6 [
roads ;; agentset containing the patches that are roads
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4 H4 Q N8 ^4 D' j) L) xturtles-own) R: T% x( K; t7 `+ V+ d' W a
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) J7 \4 B$ j4 k speed ;; the speed of the turtle7 o- G- K5 L) X
up-car? ;; true if the turtle moves downwards and false if it moves to the right
$ O+ D: y' f; D* ^* L2 Q: h D wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
8 [5 B4 \ ~4 ~ f% [ green-light-up? ;; true if the green light is above the intersection. otherwise, false.
- U" k3 M- k; r4 T8 }& \) k2 ` ;; false for a non-intersection patches.
2 Q, P: L; Y0 Z5 ?4 r+ N& y3 p my-row ;; the row of the intersection counting from the upper left corner of the9 r3 p/ K$ B0 K
;; world. -1 for non-intersection patches.) s1 l+ M: |7 L" q
my-column ;; the column of the intersection counting from the upper left corner of the* K* M+ A! v: |& f
;; world. -1 for non-intersection patches.! Y9 x: ^' U& p s8 f/ Y8 ?
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
& r0 P+ @, U8 K" G4 G$ s x+ \/ m f2 I auto? ;; whether or not this intersection will switch automatically.- r! ^1 E W# J. P1 Q, M
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;" H" X, X9 s4 ^4 Y6 K
;; Setup Procedures ;;. n& \# h' z% P3 h7 V
;;;;;;;;;;;;;;;;;;;;;;# ?$ L# a8 y& Z9 S2 I' x6 i
- W9 F g+ N) @/ B5 T;; Initialize the display by giving the global and patch variables initial values.
) y, b; e; c3 t c;; Create num-cars of turtles if there are enough road patches for one turtle to4 y$ G* r. v& ^
;; be created per road patch. Set up the plots.
0 y: {! V- h& F8 ~to setup
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setup-globals
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3 v0 d7 y# F( [; U5 r& z ;; First we ask the patches to draw themselves and set up a few variables% J# l, A* w2 @
setup-patches: t6 u( o+ O& k9 s/ j6 h
make-current one-of intersections
7 u% Q- v$ T0 q* D2 e) i label-current' r" C3 }( l p# T2 A
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set-default-shape turtles "car"8 h/ g& B* r. m' V. ]' b
8 R! n7 K5 [/ |' `- i) @& F if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of ", }7 t. L- x5 {% ^
"road. Either increase the amount of roads "6 k4 k& |- L/ a& l1 M" Z P
"by increasing the GRID-SIZE-X or "
; P# e# h9 c, Z% h: |6 _# j* J "GRID-SIZE-Y sliders, or decrease the "6 [- h6 {, q/ ~0 J0 r1 @
"number of cars by lowering the NUMBER slider.\n"
; ^% I R. w' q; i: N "The setup has stopped.")
0 W; W7 C, V' f/ t stop
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8 Y: _( m" t" k- N8 L ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color3 q8 ^: c5 k0 }: p
crt num-cars2 j1 x( j7 F9 f) D
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9 @5 n9 r5 m$ i( X; H setup-cars
$ _0 S6 p j- B! E set-car-color# ^- \7 `: D9 h* U i
record-data
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- ~+ A: F k: m R ;; give the turtles an initial speed+ |3 s8 y; v7 x t: Z8 e& j
ask turtles [ set-car-speed ]( X8 U5 o. x' W
- I1 |4 b: g- S3 i* M+ W' k( x0 a reset-ticks. M, X; Q4 R: {0 v
end, q! l% c3 C& H+ E/ h0 o/ A
0 ]' O+ c( o& v) S8 b# d;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
1 W* g5 C* x( C6 ~, d# L& v set phase 0" U/ |* Z; s! ^5 B
set num-cars-stopped 0
( C$ l& j: o/ a; U set grid-x-inc world-width / grid-size-x9 o) K. w) `/ z( n; f: L: u
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 boundary9 ^6 [7 S0 G5 e) j, N: Q8 Q
set acceleration 0.099* W" X: u! k$ E' @1 K; l
end
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) T) N4 b! g* p& T;; Make the patches have appropriate colors, set up the roads and intersections agentsets,3 z/ j% I* A" V- S1 X# y% F1 C3 C
;; and initialize the traffic lights to one setting% s7 P5 y/ L& C! ?5 |/ U: ^/ w
to setup-patches
* q' m. j, ~' B U. M9 G+ X- o' p ;; initialize the patch-owned variables and color the patches to a base-color
9 Z2 G, Z3 J& N* K; ] m* a0 A; | ask patches) c! ?' N$ V* u- T$ q+ n0 c
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set intersection? false
. e+ M8 ]' r/ {6 v# d6 i8 @# M6 V set auto? false" X8 w/ u: O! v* _9 Q, v
set green-light-up? true2 b/ J& w# M j( a k) J8 o, y& b6 B
set my-row -1
2 N4 B( n7 `, M) r! H( ^ set my-column -12 S& @. t2 v5 u
set my-phase -1
?- P) f5 t7 v0 ~/ q set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets3 T" P# ?: u1 [# p5 k
set roads patches with
4 X( R& ?# i, n. A5 l7 b$ u [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or$ A; d" P- C# G5 ]9 j' P( _* y$ ~
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
% s0 ^3 V5 Y# r: T. d* v8 D set intersections roads with
$ v3 P0 ~. [' s+ }2 j0 D! M8 D- K6 w [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and$ \ f. N5 ]) C' T E! C/ b. W
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]$ m6 W; x7 a5 Q
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?# A4 E/ R* J7 g. c0 ], y; j7 L
set roads patches with
( G& J4 `. k0 j, u! [ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or1 i9 X8 @ o% R: N
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ T. c9 o2 n Q, l
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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