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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。
3 d- @+ i0 }8 n G6 V2 dnetlogo自带的social science--traffic grid这一例子当中,
3 r* h) A8 Q3 c! sglobals( G4 \: k# S2 p w
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9 C8 e. M" I9 i r! y1 c( c grid-x-inc ;; the amount of patches in between two roads in the x direction* @/ S" k+ `: j. A( ?. |) _2 w
grid-y-inc ;; the amount of patches in between two roads in the y direction8 i6 L& H/ Z* d) t" J6 r
acceleration ;; the constant that controls how much a car speeds up or slows down by if! H0 l+ v7 a( [. i: L' B7 F
;; it is to accelerate or decelerate$ f: O, ?! D- P* L0 i% v
phase ;; keeps track of the phase" f; l1 f, s C
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure C2 D q) F+ q
current-light ;; the currently selected light
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5 v4 L" b( w7 _) v ;; patch agentsets4 E7 ]! R, o. O% @- k; o4 L0 ^0 a
intersections ;; agentset containing the patches that are intersections
" K* ]+ k; l6 ~! G7 Y! n; V roads ;; agentset containing the patches that are roads
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1 W, g( o' G5 {- Y' D5 _turtles-own% s _; F' @, a# G& e. @8 c
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* D' ]* v5 o9 i, C5 `( S9 N5 M g speed ;; the speed of the turtle
; P2 u0 B8 O5 ?* \" T$ X up-car? ;; true if the turtle moves downwards and false if it moves to the right: w. y4 |( |, T; F6 `! d+ V- h
wait-time ;; the amount of time since the last time a turtle has moved
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8 z/ P$ j5 Z: p9 opatches-own
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intersection? ;; true if the patch is at the intersection of two roads* V9 k3 m9 |8 R y" u9 ]
green-light-up? ;; true if the green light is above the intersection. otherwise, false.: A, U. H- V- A7 Y- y& @* c1 |$ [
;; false for a non-intersection patches.
9 g8 v1 }& @' T6 R l' w my-row ;; the row of the intersection counting from the upper left corner of the0 N- F9 R* C. m: o' i; M7 q1 y$ D
;; world. -1 for non-intersection patches.
+ a0 {4 S# p& \5 `; l my-column ;; the column of the intersection counting from the upper left corner of the1 x. O8 ?: f0 L1 c3 Y/ n: G! c: e
;; world. -1 for non-intersection patches.
9 I. D$ `9 g0 w; C1 U my-phase ;; the phase for the intersection. -1 for non-intersection patches.) @5 n# ^$ e! [# b& R& l
auto? ;; whether or not this intersection will switch automatically.
5 I3 l C! \- C H: p! c ;; false for non-intersection patches.
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, K- E6 q1 P1 Y- x$ B) X" `4 F: V+ q;;;;;;;;;;;;;;;;;;;;;;( F5 L9 E0 t, `; |
;; Setup Procedures ;;
5 m; T# X, {! v7 D6 r;;;;;;;;;;;;;;;;;;;;;;
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3 `0 _% p! J! F! x" W, `;; Initialize the display by giving the global and patch variables initial values.8 f. M w# S( D# B
;; Create num-cars of turtles if there are enough road patches for one turtle to
$ r: e5 q+ P9 W0 I& }# d$ a ?1 I. _;; be created per road patch. Set up the plots.; U9 y5 {3 m5 l9 i& j* l+ k
to setup, ]7 n6 k4 i( ]/ W! ~/ j! x5 O: M
ca
# i$ [; Y* s9 h5 N0 K setup-globals H8 q5 M$ y. E9 b+ f6 U/ Z( `3 T$ g
2 O8 j) j0 n& k! C ;; First we ask the patches to draw themselves and set up a few variables4 b; b# O6 k, K0 q; G3 v/ k$ I
setup-patches1 D% d7 E! N W/ m" \
make-current one-of intersections/ v. ] U% q% q, h( R% _) @! y
label-current0 b$ Y A& n8 r% J; y; T
5 R) {" V9 `$ e6 f& L- n set-default-shape turtles "car"
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& `$ n3 }% T/ X. ]- | if (num-cars > count roads)8 M' O. J d* @
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% |) H+ M% w. i" h user-message (word "There are too many cars for the amount of "9 E; q" L% j* X1 W
"road. Either increase the amount of roads "2 D% A$ H+ J8 J7 L1 X$ k- n
"by increasing the GRID-SIZE-X or "8 u0 X7 \* T9 T0 [0 s4 c: E W2 }
"GRID-SIZE-Y sliders, or decrease the "
" Q2 s2 ]" O1 c0 O "number of cars by lowering the NUMBER slider.\n" p. `) D) s) Q
"The setup has stopped.")
, v8 L7 s1 L8 c- l% @; |4 M+ v stop ~! I4 [: N+ h" p
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- d& S, V: x0 _ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
" w$ j4 t5 F7 X crt num-cars& i7 B+ o, B0 K$ N0 d; S0 D
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setup-cars
& l6 _1 c; l$ J: \# ~ set-car-color
6 C3 Z9 `) q, b0 K9 a7 | record-data1 ~9 H, m' R R+ C) M, L
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;; give the turtles an initial speed: P0 X/ G0 a5 n. G! K1 Y& a
ask turtles [ set-car-speed ]# G1 I! T4 v+ O7 y
9 ^8 P) X, M; C6 [ reset-ticks
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;; Initialize the global variables to appropriate values' `& x8 \) }) Q4 z* C
to setup-globals6 r3 K8 Z; c: d# U4 K) h s* [
set current-light nobody ;; just for now, since there are no lights yet
# t' t3 g- f% X, ^ set phase 0. K* M, J2 O) Y2 g$ j
set num-cars-stopped 0
5 f% C- x/ c- J; m8 x7 ~3 X set grid-x-inc world-width / grid-size-x7 Q( e# g B% l% q0 E" E
set grid-y-inc world-height / grid-size-y
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' P' o ?2 R; K0 Z2 k) @$ ] ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary7 z M, R `, B" L2 M% @. O
set acceleration 0.099' d7 r4 d" Q- [
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
$ E! d/ q h$ i6 o9 O; h;; and initialize the traffic lights to one setting
$ P4 O" _9 _+ D2 n4 ?to setup-patches; i! g! ], z! e+ W/ c- X
;; initialize the patch-owned variables and color the patches to a base-color e" e* s) e& U7 S, `" _
ask patches% d0 V2 c* [* B+ }( D
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+ h! J6 E* _# V9 s0 G: N set intersection? false
2 {$ _( D( z" c8 [4 M9 G; U0 Y9 F set auto? false' y% f' ]: f1 n1 j1 y9 S2 A
set green-light-up? true
8 p/ v5 m4 \ y; `# I/ x set my-row -1: T+ Z8 Z/ O# A l' s
set my-column -1
* _' J# }2 ?% S4 T- u set my-phase -1
S4 e' c$ P2 q: L set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets5 ~( r R* { _' S- c% E/ S# u
set roads patches with% z* @; R# `3 ?8 ^" N, l
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or$ P: g" C, n3 V
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]) n( j5 W, q* p
set intersections roads with
% j8 B! L& R9 ]- O. d0 x! Q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and, p6 P5 | Z7 x: }3 u4 ]
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 l( s/ z2 C Q" }
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ask roads [ set pcolor white ]
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其中定义道路的句子,如下所示,是什么意思啊?
5 ~5 u" M) t+ \6 m3 \7 C$ R% \ set roads patches with5 [% G5 m \' r8 }
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
, |/ J5 C5 h, R" C1 A) u" R# L (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
" \+ B X' ?4 B7 Y5 N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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