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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。9 |3 h& @; T9 `0 P
netlogo自带的social science--traffic grid这一例子当中,' K; v7 n$ w s. ^
globals R4 |5 s1 Q4 J- E5 `8 l
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grid-x-inc ;; the amount of patches in between two roads in the x direction4 I4 J1 W0 y1 p% e0 N+ l! |& N
grid-y-inc ;; the amount of patches in between two roads in the y direction
" ~2 P; E* h; q* Y+ f" Q$ M acceleration ;; the constant that controls how much a car speeds up or slows down by if
" ] M: f0 W' a* M" G6 r! @ n ;; it is to accelerate or decelerate
4 }( M* h; z' A( U phase ;; keeps track of the phase
7 y0 d/ q" \3 l1 U num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure5 ]2 `( D x/ M- x# T
current-light ;; the currently selected light
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;; patch agentsets
0 t" w# @2 ]& p% I& f& b% H intersections ;; agentset containing the patches that are intersections& m6 O' z/ }6 F
roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle" j) G8 v/ d2 ]! J: J/ N$ D& _
up-car? ;; true if the turtle moves downwards and false if it moves to the right! ?1 Q& ?1 R+ T! O6 h
wait-time ;; the amount of time since the last time a turtle has moved
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; I3 p2 r# A) R4 b: H2 _; P4 mpatches-own5 q! [8 B: ]- r2 j9 ~! F: S, M
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intersection? ;; true if the patch is at the intersection of two roads1 b6 y( u8 J6 c
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
2 @2 v, Z2 Q3 n2 a9 q) l ;; false for a non-intersection patches.
* a8 v! p2 [) X0 x+ y" ^ my-row ;; the row of the intersection counting from the upper left corner of the
2 g- `, i5 p8 e% q8 k6 }% v) u/ n ;; world. -1 for non-intersection patches.
2 ^3 |: e: b0 @7 v my-column ;; the column of the intersection counting from the upper left corner of the
- E2 M/ |2 v3 d; F0 L ;; world. -1 for non-intersection patches.
0 R) c8 ]5 z2 f0 F% w+ f! `* K7 m my-phase ;; the phase for the intersection. -1 for non-intersection patches.
& S5 J" X$ z6 X' ^% y7 D5 T; v auto? ;; whether or not this intersection will switch automatically.
5 T& _5 L6 Y& i$ W& o ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;; u8 y# z$ x0 w: O q
;; Setup Procedures ;;
0 s% T* u* k1 E2 s/ ?% q% R# K$ h' J;;;;;;;;;;;;;;;;;;;;;;7 s( G, V- U. I$ _ R1 D% o
; n2 w) P0 e# ^' V2 }& q;; Initialize the display by giving the global and patch variables initial values.' b+ [/ f1 j9 A& x; L6 L& k
;; Create num-cars of turtles if there are enough road patches for one turtle to! s3 e0 g* f& n# s# r5 R; Y3 D n
;; be created per road patch. Set up the plots.6 A; d0 l6 B3 p( E! l: v1 C
to setup# R1 O7 g8 r0 e1 A- T+ M
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables F L) |% O' [) m0 Y" q) H
setup-patches7 s' V: N! p5 Q% f
make-current one-of intersections" y6 l& q( s6 I6 J$ \. H% E! q
label-current l+ C: K3 I# C4 ]
5 p1 j1 ^* }, m set-default-shape turtles "car" x! M4 Y; z; s
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if (num-cars > count roads)7 G& b. v$ n2 d
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user-message (word "There are too many cars for the amount of "
9 m0 D. U& d* ? "road. Either increase the amount of roads "
/ ~% ~1 i3 A7 P: o r "by increasing the GRID-SIZE-X or "
/ ^6 e+ S+ `2 T1 [1 ?5 o5 l "GRID-SIZE-Y sliders, or decrease the "
9 f6 ^/ b0 P! G" d5 |& _: r& w- U2 i "number of cars by lowering the NUMBER slider.\n"1 M" R% I0 t7 M) `1 R
"The setup has stopped.")% Z- x8 G S [, ~
stop9 t; ?' w9 f$ ~3 O3 f
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color7 U* _7 s$ f3 H6 L" E9 `
crt num-cars0 N G- E% M$ N. f8 N& k. ~
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3 v5 J& L1 \8 b- q" T setup-cars) X! R. y) d" V9 r
set-car-color
3 d, f1 P; w7 p record-data
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;; give the turtles an initial speed
% B/ Y" N% V3 a: @ ask turtles [ set-car-speed ]+ G1 `& U% n f
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reset-ticks6 X5 N6 I, B* d7 I# `/ G3 N
end
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' t9 m6 j( I% h;; Initialize the global variables to appropriate values$ j$ i' Q2 O5 ?; ]
to setup-globals
4 E, o; ]; [$ k" `* A. Y" M% t: R set current-light nobody ;; just for now, since there are no lights yet+ `$ o% i3 y+ Y- ~
set phase 0$ d) F" J. P7 y" X: x
set num-cars-stopped 0( m) p" c( V% z, `2 i2 W
set grid-x-inc world-width / grid-size-x; q$ e; [ j- j" c3 n$ S
set grid-y-inc world-height / grid-size-y/ V G4 f% `7 f! k! }+ B
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary9 L% d; P5 B1 G3 J7 y
set acceleration 0.099. c/ C: k& A4 X# H$ j0 U
end
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( q$ S' \1 v, N |/ ~: M;; Make the patches have appropriate colors, set up the roads and intersections agentsets,! _' H! F( S1 n0 J C& B ]
;; and initialize the traffic lights to one setting& Y* Y& u; T5 i
to setup-patches6 L, d e; ?% f
;; initialize the patch-owned variables and color the patches to a base-color
# w! X: _; ~* K" i; x ask patches+ H3 C6 s/ c5 V" c$ z% ~% w: _
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set intersection? false1 l6 p1 q' z, \
set auto? false
# F$ O( X+ T c! x8 `4 p" e set green-light-up? true
2 c4 G. ~. ]" `/ _; N set my-row -1' l& t( X+ T" P f. e2 @
set my-column -1' F5 m6 [. a& F8 y+ i# n& s! M
set my-phase -1, r8 X" W) \2 w- B) O6 g4 @
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets* w# L; j2 D, Y7 G/ w
set roads patches with9 `8 k9 J4 q4 R/ G9 p# v! S
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or. {/ b2 W- N; K2 Z% H/ g
(floor((pycor + max-pycor) mod grid-y-inc) = 0)] ]! |$ I: N% P. V
set intersections roads with
' l4 Z3 a. G) M; A7 c2 R6 U4 ^/ _ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and9 b: B( u3 G0 R m$ Y* Q
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]0 v3 b5 R) K, ?
setup-intersections
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: h! t9 `0 |# s S' A4 {; F. t2 q其中定义道路的句子,如下所示,是什么意思啊?% S% i2 ?. P4 \: Q& h
set roads patches with8 C2 [1 t' H [6 m t' m
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or$ G$ _: ^; \0 X8 W
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ h) u6 G6 k! {3 _: P4 }
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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