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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。: n5 |% ?) @9 w" z. C
netlogo自带的social science--traffic grid这一例子当中,
( r, e! ^: X- }4 R6 z% sglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
( g+ O. K; F+ q! \, b' Q) g s2 J grid-y-inc ;; the amount of patches in between two roads in the y direction. r; G' X& @( b( G
acceleration ;; the constant that controls how much a car speeds up or slows down by if
" W& {: N' F# ?. V ;; it is to accelerate or decelerate9 _- I, e% r8 Y! R7 {* j# a8 i, F
phase ;; keeps track of the phase, `6 u b l. u" K& q7 A5 ~2 m
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
# n8 W% p* ~5 q2 W' g1 N! R( `. p4 c current-light ;; the currently selected light0 L# |$ K) j7 L4 |- Q+ X. B
; ?" |" E% [) T ;; patch agentsets
2 q5 u4 x. |. B' b6 b1 t intersections ;; agentset containing the patches that are intersections
! A& A+ v' m# J- O5 t3 e roads ;; agentset containing the patches that are roads
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( J! Q! `* q0 L0 Qturtles-own7 d- f/ A/ \7 \2 A0 J$ r
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4 k& e* A* Y+ k speed ;; the speed of the turtle8 c" s8 C! r2 P. C, X
up-car? ;; true if the turtle moves downwards and false if it moves to the right8 V1 L4 ^* N- c3 d8 h. `
wait-time ;; the amount of time since the last time a turtle has moved! Z8 w6 j% Z8 g+ G; C& _
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# {7 t4 N: |2 b$ rpatches-own8 S- h4 d) a7 ?. w. H$ A o7 ?
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% X. `" c# t; |& G intersection? ;; true if the patch is at the intersection of two roads& `4 a! r6 r" y4 y% x+ m: K/ |
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
+ f1 ?5 z& X% n0 y- o, f ;; false for a non-intersection patches.+ o; n3 i. }- ^8 C4 U3 B& n
my-row ;; the row of the intersection counting from the upper left corner of the
, f/ k- R( b V* d ;; world. -1 for non-intersection patches.% @( ^/ ]8 Q% I6 y4 H
my-column ;; the column of the intersection counting from the upper left corner of the* |# b, d! l" Q7 L+ b. B. Y
;; world. -1 for non-intersection patches. p3 h! [! w7 S
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
$ h4 K) x& E. k! d* I5 z auto? ;; whether or not this intersection will switch automatically.
* z# q/ s5 Q1 m) ^! V5 Z$ p ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;+ G7 X: n$ V, a K7 ^2 o+ r9 @& S
;; Setup Procedures ;;! O! N2 _4 Z# I1 m6 C
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.7 F7 w' l5 d$ y% r. s4 Y& }
;; Create num-cars of turtles if there are enough road patches for one turtle to% Z* Q* O4 u) _$ m6 s+ y
;; be created per road patch. Set up the plots.
# S- j9 Z) q& C* g8 b9 p# ~to setup1 y$ M* k9 T' U4 D% I) {
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables/ b5 t2 z& z/ Q$ f
setup-patches' B% q0 ?' e0 N; t+ }( x1 ~
make-current one-of intersections
6 C7 P0 K0 }% v8 a+ S label-current; K% e. t+ v8 d
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set-default-shape turtles "car"+ d; i/ ^% z) S+ @2 a. h
$ x5 m7 \& j, H; R if (num-cars > count roads)4 o% ?9 \( G$ a& ?( |8 G2 c+ g
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! g7 c/ }" A" Q" D* ]7 f" t G user-message (word "There are too many cars for the amount of "' f& Y* J4 `- f$ l0 h# i0 L: ?3 H8 Y
"road. Either increase the amount of roads "( K2 @; d( R" O) D0 _
"by increasing the GRID-SIZE-X or "
$ k! e4 p! T1 F0 l# W& \( C# n "GRID-SIZE-Y sliders, or decrease the "& n+ W' W7 h6 E* n: _
"number of cars by lowering the NUMBER slider.\n"' c0 R5 T7 }& D* W+ N
"The setup has stopped.")2 ?5 t6 n6 P5 v- _0 ^5 i+ R3 W
stop$ U4 q; E% p. {! Y% e B
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color% M# x" x9 ^$ q1 A# ~; o0 u
crt num-cars
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setup-cars8 A& {/ t ?4 ~
set-car-color
0 L# [6 B# r: c; a/ I0 } record-data
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( S( P. q9 C) `# E0 j0 K; C ;; give the turtles an initial speed+ q4 R! l4 K2 }. i' G5 g3 x2 z
ask turtles [ set-car-speed ]
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reset-ticks2 v5 p. {+ w: J( j& Y; F( P
end' |6 e- A! p' k
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;; Initialize the global variables to appropriate values
& @3 p; \/ p+ R" N' @! Q# V1 Hto setup-globals+ V7 n" X; P$ b _9 |2 h# N
set current-light nobody ;; just for now, since there are no lights yet' D3 V' S# a- J0 R
set phase 0/ Z+ c7 E. h* c% U
set num-cars-stopped 0! X3 n# {2 k. T) P/ W3 I
set grid-x-inc world-width / grid-size-x
( k9 l, v; \6 @6 N) |) X set grid-y-inc world-height / grid-size-y/ v3 a% r& T1 I: U9 n
& L) J& X' `0 L, B2 i ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
! H2 L, T) B* h: S$ P; M set acceleration 0.099
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; \/ X) y6 B" o H: V& x; D;; Make the patches have appropriate colors, set up the roads and intersections agentsets,; n3 _' _; N1 \! _* [
;; and initialize the traffic lights to one setting
& i, t3 @, |; \( Z" g' Ito setup-patches: K( g) O4 K% ]; ~( k8 v
;; initialize the patch-owned variables and color the patches to a base-color& A. d& E) Y/ {" Y4 ?, |
ask patches
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$ ]8 u( D( i& m set intersection? false
8 @/ E/ V; x8 }( V set auto? false
5 m! C# g2 n1 x/ `1 i, |: | set green-light-up? true
& C5 t0 i3 }0 _ set my-row -1
( `2 J0 h0 Y! _ set my-column -1
( O9 r5 h# r) A set my-phase -1. f& D: t4 b( h" n8 E+ G
set pcolor brown + 3
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& Q+ t* O) m! J$ s4 N7 j$ m: s8 A+ z8 j ;; initialize the global variables that hold patch agentsets
& }4 z) r8 P. e set roads patches with
% t2 X4 t5 [+ a0 f% K [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
$ v$ U8 F! s8 H9 C$ o# P" p (floor((pycor + max-pycor) mod grid-y-inc) = 0)]) f5 B2 {' p$ I0 u. i/ b' |7 v
set intersections roads with
/ h/ K. B2 t! P4 m [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
2 N/ R! G6 f# E0 G* K (floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 @8 M7 [# b. R
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ask roads [ set pcolor white ]( \' U4 T9 y4 R# o3 j' B& R! U
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?, \6 I) ^1 W, V7 ~( l
set roads patches with
$ z! x4 J0 ~5 P" [" @7 C2 q& E [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or1 R/ W! N' L0 D5 [
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 s- @- L- I. U0 i, 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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