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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。4 _2 y8 `$ _; Q' s
netlogo自带的social science--traffic grid这一例子当中,
+ B2 a: Y# E M; V g6 k! ~globals
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' `8 h' S9 p3 [- t6 D N, n grid-x-inc ;; the amount of patches in between two roads in the x direction- C. E5 U+ k5 C8 O
grid-y-inc ;; the amount of patches in between two roads in the y direction% S2 K/ p. }/ |3 `* u
acceleration ;; the constant that controls how much a car speeds up or slows down by if+ B. R! U4 {2 t2 h5 n( J+ N
;; it is to accelerate or decelerate
9 ~+ ~) E- P8 j- ~$ V5 F5 f phase ;; keeps track of the phase0 w1 p- ~! Y; N+ w [
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure1 @) w( n' f) a: C# R! F: y
current-light ;; the currently selected light
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;; patch agentsets
* {. I; S$ M+ N8 W' z intersections ;; agentset containing the patches that are intersections/ \7 }0 r# {/ I$ n
roads ;; agentset containing the patches that are roads4 P( d( `8 I6 S' {
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turtles-own
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speed ;; the speed of the turtle
% P, F h: a9 }/ @& p up-car? ;; true if the turtle moves downwards and false if it moves to the right
. K, i5 ]# P" S/ } wait-time ;; the amount of time since the last time a turtle has moved' P5 N2 H0 |2 t C
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! b7 Q% U% F8 V- vpatches-own
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5 Q9 ]: s2 R* c8 D7 e; i intersection? ;; true if the patch is at the intersection of two roads$ V. v" u4 c+ m7 H# f! Z, e. l
green-light-up? ;; true if the green light is above the intersection. otherwise, false.; u: X9 K7 }+ y0 C, d+ w( |
;; false for a non-intersection patches.
3 E9 d, A0 P9 k% p# C! d: R2 B" w my-row ;; the row of the intersection counting from the upper left corner of the( W* \8 q! Q- ~- b- G0 U* s+ {/ ?
;; world. -1 for non-intersection patches./ R: t/ s7 d7 N, D$ q* b. ~9 _
my-column ;; the column of the intersection counting from the upper left corner of the
& @, ~* C, l0 q6 b* q" T) h" ? ;; world. -1 for non-intersection patches.% C! L$ M/ A5 S% r- k M q$ U
my-phase ;; the phase for the intersection. -1 for non-intersection patches.2 x8 ?4 u, |% D4 p1 m C) m2 A/ r2 D2 F
auto? ;; whether or not this intersection will switch automatically.9 `( J/ ^- q# _$ H& b
;; false for non-intersection patches.
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' C; ~: N$ w7 Y; b;;;;;;;;;;;;;;;;;;;;;;
/ {; L9 b3 v7 S+ G;; Setup Procedures ;;
$ `" `0 o$ c, w8 S' w, Q;;;;;;;;;;;;;;;;;;;;;;- e9 D5 ?3 F. e5 }: J2 D7 M. J
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;; Initialize the display by giving the global and patch variables initial values.
7 X2 N2 ?0 x% J+ g! x ];; Create num-cars of turtles if there are enough road patches for one turtle to
0 U9 C, N4 @8 U g' { H;; be created per road patch. Set up the plots.; m0 r+ E7 q* M4 N7 \7 ?
to setup
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setup-globals
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2 V' @7 s4 C' U8 y ;; First we ask the patches to draw themselves and set up a few variables
E$ {' g* E! h$ X% u- B7 V M; b setup-patches: c0 }& k' |4 C) X
make-current one-of intersections- h7 ?: P" m' b& x6 b
label-current
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set-default-shape turtles "car"7 v% i! u6 ~ ]4 y; ~8 W
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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 "
1 `% N# z7 V+ y' A "road. Either increase the amount of roads "
7 i8 r4 `4 q6 b& g "by increasing the GRID-SIZE-X or "$ D. ?$ x/ H( c; p
"GRID-SIZE-Y sliders, or decrease the "
7 h- p; M9 _" @' A8 i# h/ N! @2 h "number of cars by lowering the NUMBER slider.\n"4 r# b4 v. g0 @
"The setup has stopped."); b0 B8 I% h! M) g }, i4 ~8 `" ~
stop
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$ i" \ ~3 ^# x% e ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
# P2 ~ G R, c2 o9 H+ q5 h crt num-cars
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setup-cars p- w% L! ]2 z! a! P
set-car-color
2 j. e2 d2 ^& |& u record-data
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;; give the turtles an initial speed
3 T, v* c: ]- G b; q* W1 y3 J ask turtles [ set-car-speed ]$ E7 f% \3 H$ ?$ K) @
5 X7 m! |; k* n0 c reset-ticks1 @. A& S; K# p# b& a( O/ {# n L
end) Y0 O1 O B8 k
& [# u' [' @4 Z# M7 `" W+ @;; Initialize the global variables to appropriate values& j0 ~$ X7 q5 r3 k
to setup-globals
% h- s5 K' N+ e' R0 ~8 y set current-light nobody ;; just for now, since there are no lights yet
! Y9 A1 N5 @, k. F! v, ?: D% S set phase 0
8 f* U9 l1 D; b! ]& M set num-cars-stopped 0% K L; J: r7 N) }+ U
set grid-x-inc world-width / grid-size-x
* S1 @2 ]; c- G+ a set grid-y-inc world-height / grid-size-y5 w, p. }4 n5 F
5 F7 w& b, ?( n K ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
2 X5 C% \+ l" F2 R- Z set acceleration 0.099
8 j2 a! b/ F# G* b/ p8 }" Qend
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/ i. w9 p: m/ U8 Y/ y# I;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
0 k0 f J7 V. ~( a( Y7 l1 X;; and initialize the traffic lights to one setting
5 ^0 S- s, b6 V4 \: ]to setup-patches+ n( ?6 Y$ W9 `( b: p2 J8 c) R
;; initialize the patch-owned variables and color the patches to a base-color
+ B* P* z1 [( a& i2 z2 L ask patches# I% s( T6 V) v+ i _( l
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set intersection? false
) X% g3 j/ g$ |( N+ L. s' D set auto? false
7 a( S5 } } K, T& z6 e set green-light-up? true
- i" N$ j: M9 h; i; s% `: `2 G set my-row -1
9 D: |4 m5 Y) [ set my-column -19 |. c; o; ` @2 G3 Y( I8 X* B K
set my-phase -1
: S' u! p) J5 J5 D set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets9 w$ f- ?/ E$ e' d4 d8 }
set roads patches with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 h: g: Z0 l3 G& [. V set intersections roads with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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4 C9 R3 o) q# _' A7 M# K ask roads [ set pcolor white ]" a; z! P2 Q" L0 M- E# `% V
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?8 o/ Y3 B# L w0 q) N1 G6 @
set roads patches with
# L$ B: ?/ R, D: } [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
+ j5 J; m" I9 S7 s& A (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 G* X3 W0 ^: \# M2 d) m; 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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