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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。" c- N4 H% }, _) @
netlogo自带的social science--traffic grid这一例子当中,2 M+ J! z; K3 u% y; ]9 t
globals! |; O {# x8 z* `) t( H
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grid-x-inc ;; the amount of patches in between two roads in the x direction# s$ E' Q" j7 B. L& N* A
grid-y-inc ;; the amount of patches in between two roads in the y direction, Q1 Z8 V& B3 F
acceleration ;; the constant that controls how much a car speeds up or slows down by if1 M6 s" u4 K8 z
;; it is to accelerate or decelerate
# d1 b, ]3 l: P% `+ V7 x phase ;; keeps track of the phase3 M" t% F- i, Q; p
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure5 k( L! ?9 m% B Q) r* F
current-light ;; the currently selected light3 c1 t/ O: N9 @- r: X; K
" g5 r& R3 F" C) A& z# b" a ;; patch agentsets
4 Y4 Z1 s, i2 M+ O intersections ;; agentset containing the patches that are intersections% I. j# ]( Z* @* Q. s: l" x
roads ;; agentset containing the patches that are roads) }% ~) o& _2 u; p- G- [* Q
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( k- R1 u3 T( Cturtles-own3 ?# t5 m( B8 t6 \, z
[
/ }: _9 `; Z( y! F) t speed ;; the speed of the turtle, m9 ?) K- n" n0 }* j
up-car? ;; true if the turtle moves downwards and false if it moves to the right
/ k. Z5 w1 x B- m/ O wait-time ;; the amount of time since the last time a turtle has moved ]* `4 }1 z. G2 W& c: O
]
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads6 o2 W/ @! f' z" m
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
0 k; T- ?+ A; J ^8 t; C* P ;; false for a non-intersection patches.
3 r) w' J; F7 C% ? my-row ;; the row of the intersection counting from the upper left corner of the& d. T9 n6 A" a9 f: A
;; world. -1 for non-intersection patches., d1 `; l! Q. A) Z7 ~
my-column ;; the column of the intersection counting from the upper left corner of the3 |4 E1 f. f# d0 I, ?# l) ?) v$ O9 B; s! a
;; world. -1 for non-intersection patches.
! R. j! C I3 ^+ _( g my-phase ;; the phase for the intersection. -1 for non-intersection patches.) ^1 Q( {) c/ Z: ~6 ]) X3 k
auto? ;; whether or not this intersection will switch automatically.
9 z! z7 V/ \% @" T3 w ;; false for non-intersection patches.; Y1 h- U( g5 ~! J! T
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& |, l$ G) N& C) `# e8 n* Q+ V;;;;;;;;;;;;;;;;;;;;;;' j3 M! v. t. ?& i$ h
;; Setup Procedures ;;
7 {1 S1 c% c6 X0 D/ s: _# k& K;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values./ B% [; O/ |+ H1 T
;; Create num-cars of turtles if there are enough road patches for one turtle to8 M- Y7 o: N6 j/ b, u1 W7 w$ L
;; be created per road patch. Set up the plots.5 L( a! S8 y6 e# _7 I
to setup d' t# T& `# n0 r1 c
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setup-globals
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. g2 p7 `& Y7 O* d) ^1 R$ X* C ;; First we ask the patches to draw themselves and set up a few variables% a% i# d' W' P- R2 L
setup-patches
1 ^( @# @6 h' Y. T make-current one-of intersections4 }+ }& i" D2 N* b. V& U1 x
label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)% L: b1 k1 T" ]7 l2 n. j3 K
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user-message (word "There are too many cars for the amount of ") N; Z; c; S# L" d- w
"road. Either increase the amount of roads "
! N! n) V: n8 N; N. S "by increasing the GRID-SIZE-X or "
) z) X6 V. \5 W9 F0 }; B3 } "GRID-SIZE-Y sliders, or decrease the "
# {+ y, Z2 U- p+ e "number of cars by lowering the NUMBER slider.\n"4 @( Y9 c- |% g
"The setup has stopped.")
; u0 u3 B. {( ~+ J2 j! b1 r stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
* n/ H( N" X7 W- m) k& ^9 b crt num-cars: N- v5 e0 `, z: E
[
* c, N! y, h- y: J; }$ s setup-cars
$ }1 h/ C; G% k3 s/ | O1 ?- l set-car-color5 m5 B& G8 Z+ X3 Z
record-data% B- ^8 W% r3 A% E
]
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8 \' U: D6 x- t0 Q ;; give the turtles an initial speed
8 E$ u& I, T2 J6 Z# E; M8 W! g. g ask turtles [ set-car-speed ]& L7 m; c! b3 M
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reset-ticks
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2 s: V( Q# P6 G# n: v: {, i;; Initialize the global variables to appropriate values& R; w. x ` y$ v5 `
to setup-globals, O; d' {6 ?* I7 [
set current-light nobody ;; just for now, since there are no lights yet
" k% |6 O. ?3 }% i/ Q set phase 00 P! N7 Q x+ ]7 B
set num-cars-stopped 0
7 ]. X# }/ r8 R. B" f4 l" l set grid-x-inc world-width / grid-size-x
# q/ g! X4 q* X( E: ]+ G set grid-y-inc world-height / grid-size-y$ _$ ]8 N5 C: Y# A8 c: d5 s( q' n
9 _3 j. w" I7 o; U# _ ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary- _3 ?. C+ s8 r5 ]' }& e v- H
set acceleration 0.099: {" y8 @/ L0 z- X) D* W" s2 {3 P& h
end
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( G, _' O. o ^! r. Y3 D& u& s;; Make the patches have appropriate colors, set up the roads and intersections agentsets,6 v1 Z$ u9 `6 D; {3 P2 ~' c C
;; and initialize the traffic lights to one setting0 Z8 c; L8 v$ C. Q! z, H
to setup-patches- N( F# C, T/ K6 r/ c% \
;; initialize the patch-owned variables and color the patches to a base-color. h8 s% D1 } v2 k* {
ask patches5 O* H1 g5 j# K/ I+ z7 x: L5 M
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set intersection? false- g- U/ L. H# [* C
set auto? false
3 R# u2 L$ `8 J9 I1 k' L set green-light-up? true4 T* e* S: C+ k! O/ A
set my-row -1
! e$ v5 \3 o2 Q {! H set my-column -1+ S6 r* b7 e4 f2 V; }6 e* _1 Q
set my-phase -1- Z; z6 K/ i3 k) g% a1 }' T
set pcolor brown + 3
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* x: |/ B( `( O% p. w ;; initialize the global variables that hold patch agentsets
- A; _1 c* l0 m9 p2 S$ C set roads patches with }+ d s9 H3 ^8 O$ s3 ?# M
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
$ L- k2 q' J& O( X3 ], `5 b) |$ m% M (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
# _1 h1 D; }3 G set intersections roads with4 W3 s; b; a0 Z- K2 Y3 X9 n
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
6 F- N) g/ v" L- E% p o3 R (floor((pycor + max-pycor) mod grid-y-inc) = 0)]; Y+ s4 h& I8 G) r+ W
- y$ G+ F; r3 m( H0 e ask roads [ set pcolor white ]
P$ ^5 O: d7 B4 H8 ^' \9 Q setup-intersections, T& X' s8 Z: |& r/ h
end
A( k& v% E& h. y其中定义道路的句子,如下所示,是什么意思啊?5 ~5 e! p: x. H; r% H2 {6 E+ S5 W
set roads patches with
' W1 \1 V# m5 D0 U [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or$ g, V5 V; }7 Y a: B
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 c3 a x1 o; F/ _+ F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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