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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。+ B0 Z+ U' g# L0 r0 k1 X
netlogo自带的social science--traffic grid这一例子当中,# ], T I; x5 _8 R Z z( s, q
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
' ]& h9 [- F+ ?2 D grid-y-inc ;; the amount of patches in between two roads in the y direction( H9 u, V/ [+ H0 x
acceleration ;; the constant that controls how much a car speeds up or slows down by if' j6 d5 g" X" d' p* y6 R' ~
;; it is to accelerate or decelerate
* J. ^3 e7 E* _9 c2 h6 x$ a% Q phase ;; keeps track of the phase
f6 V: f+ z7 @, f5 i0 T+ V) ~8 t num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure: e3 V0 d. b" d% L5 q
current-light ;; the currently selected light
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; i. q q5 Y$ r5 [ b8 c ;; patch agentsets
! I( ^6 v5 \# X6 k; f; G! E% [ intersections ;; agentset containing the patches that are intersections# S, l& e- _' r5 a6 m
roads ;; agentset containing the patches that are roads
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turtles-own+ y1 {( f9 b( H* {
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speed ;; the speed of the turtle2 W2 U3 @7 i2 w: `
up-car? ;; true if the turtle moves downwards and false if it moves to the right
+ O; l/ k+ C' L* l6 j6 c 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
0 i" c' X P. Z. Z- z# ?3 M green-light-up? ;; true if the green light is above the intersection. otherwise, false.
1 H% u7 }$ A$ Z+ c1 U$ t+ ` ;; false for a non-intersection patches.) ~% B# }' c& \) r
my-row ;; the row of the intersection counting from the upper left corner of the
# {( {* s# c# z3 o7 B ? |+ A* N: j ;; world. -1 for non-intersection patches.8 L5 ?$ Z% T+ q. v; q1 D, z
my-column ;; the column of the intersection counting from the upper left corner of the
$ X1 N, \" c6 M k" k. j ;; world. -1 for non-intersection patches." a1 U7 f% b, L6 u. F9 X
my-phase ;; the phase for the intersection. -1 for non-intersection patches.' z' P# v% M$ B4 a
auto? ;; whether or not this intersection will switch automatically.
8 |& c6 O- {! Y3 }, C3 P% E( r ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
( k/ I! e! |# s4 D0 K;; Setup Procedures ;;
( J7 }! ]/ {; h+ ]' l* r' b;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values." R; x* k1 L: i6 A5 l
;; Create num-cars of turtles if there are enough road patches for one turtle to' T- ~$ _5 R3 Q+ ?+ ^ g
;; be created per road patch. Set up the plots.
: I& o4 M1 E3 K* O: X) _9 U* dto setup
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setup-globals
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: y4 I; ]/ h5 X0 w% R$ m ;; First we ask the patches to draw themselves and set up a few variables8 p3 {7 D6 ?" V M% b4 k @9 f+ K
setup-patches
+ X$ V7 X' M$ r5 Z8 U make-current one-of intersections$ o1 y& N( k+ w8 S, D
label-current
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' x: m: l5 F# Y' \, L4 J set-default-shape turtles "car"1 K- I1 F( Y) n9 G! i3 E
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if (num-cars > count roads)
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7 g1 @9 Q8 f7 G1 y& t# E user-message (word "There are too many cars for the amount of "( ^( I1 n6 K' G. `) Y5 w
"road. Either increase the amount of roads "9 m0 \8 B7 `; g$ U: C
"by increasing the GRID-SIZE-X or "2 V- ?/ Q; b) s6 @& }- O
"GRID-SIZE-Y sliders, or decrease the "
, n; `% P9 @# c7 U' j& ^0 j "number of cars by lowering the NUMBER slider.\n"
0 X2 s/ N5 y. S" [ "The setup has stopped.")! y% F% L2 c9 j6 f% ]# q
stop. w. {% a6 p, ]1 F
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color8 V+ ~! Y. ~7 l; G+ g4 _
crt num-cars
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setup-cars
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record-data
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;; give the turtles an initial speed
( j" s# `5 B/ q7 a& j2 l. B ask turtles [ set-car-speed ]$ m! R# A( W' T) g2 q
. F: G2 r" h1 g reset-ticks
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;; Initialize the global variables to appropriate values. d `( |: ]8 I; h3 y+ V0 E! e
to setup-globals# Z5 S2 V. B1 o# R( W2 f# _
set current-light nobody ;; just for now, since there are no lights yet0 U3 \' T; L7 s4 L% B' b
set phase 0* d2 @( e5 |7 y H6 ]) M
set num-cars-stopped 0. N4 L1 h1 m/ r0 c2 m& C
set grid-x-inc world-width / grid-size-x% x+ e: e" k* A8 [: b! v; K( M }
set grid-y-inc world-height / grid-size-y
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+ Z6 j* r6 F( w8 m& t7 l( P% e ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary1 P9 J9 M% v/ r; a
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,' R8 h$ |6 {# P; k/ K
;; and initialize the traffic lights to one setting
& L. u2 P! ^+ `) Dto setup-patches
* k( N3 D9 G, X ;; initialize the patch-owned variables and color the patches to a base-color
: \. _5 n3 \ T; l$ A8 l/ G ask patches; q' ?/ t! B1 W
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0 a; ]9 f% w4 a2 M- \7 E set intersection? false
9 D5 t0 F3 |% r3 o set auto? false2 v1 S( p- ]. t2 G* n5 C
set green-light-up? true8 z+ a2 m6 `3 Z; g
set my-row -18 h" `; e* i3 _* [5 {0 M2 p h
set my-column -1* z& f" F) v: S# q6 ^; j! l
set my-phase -15 b* p5 j3 N; M4 K& n' U5 x! o8 s+ o
set pcolor brown + 3
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" [- p# X1 I, ?* R5 `. H8 ?$ i( Q8 @ ;; initialize the global variables that hold patch agentsets: l4 d$ C. `/ D2 Z7 l
set roads patches with1 y/ n# [2 h' G+ r$ @# q6 P& Z; [
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or; p3 e0 V* G' g: ^
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ M% b7 K' v/ Z. { set intersections roads with' N5 q1 W5 t: T' w$ ?" @" }
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and9 \' M \, v+ ~; l3 x6 u
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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- U$ g! O/ }9 |6 ?( h6 R3 k" e ask roads [ set pcolor white ], n' Z" H& S4 X7 X
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?- m) A, t( c" q( _% k. z
set roads patches with- o/ O" G, k; b" x4 `
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or0 N. Q2 ? q$ f9 H% C6 P4 w2 D" R
(floor((pycor + max-pycor) mod grid-y-inc) = 0)], P7 a" w1 ~. ?6 D- @
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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