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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。
% W3 G$ a q- L: G; pnetlogo自带的social science--traffic grid这一例子当中,: F. Q: S/ h* P: x; q( Z+ B9 N( ` J
globals
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, Q' ?0 Q: W5 a x grid-x-inc ;; the amount of patches in between two roads in the x direction3 Q% c" L) S4 i5 v
grid-y-inc ;; the amount of patches in between two roads in the y direction7 P8 W4 q0 e9 |! W2 I
acceleration ;; the constant that controls how much a car speeds up or slows down by if7 _; \( i% H9 T; g! t; x9 L' V
;; it is to accelerate or decelerate
* s# w% M, S" R% J0 k& d# a1 v phase ;; keeps track of the phase. X) [ \. L/ y% _0 G- k9 T! N
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure. v, @7 N, Z9 A% P2 D
current-light ;; the currently selected light; a6 M5 z1 N4 [6 u4 G9 ?1 M
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;; patch agentsets/ |. f( [2 O. T* \% a$ T
intersections ;; agentset containing the patches that are intersections6 U% _- a5 }! ]
roads ;; agentset containing the patches that are roads
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* \, ~. ]! A- k; s. |' O4 {turtles-own
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7 J8 X- q; z, E1 H% Z, r speed ;; the speed of the turtle- n* e6 P+ `1 p0 h( C
up-car? ;; true if the turtle moves downwards and false if it moves to the right( \1 C3 h7 r- I+ u) G
wait-time ;; the amount of time since the last time a turtle has moved
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+ s: f6 W9 i7 I- kpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
* e3 t& }9 i' N6 Q# B green-light-up? ;; true if the green light is above the intersection. otherwise, false.
9 I% ^3 i6 R+ c7 L9 [ ;; false for a non-intersection patches.6 K1 n" U: }& w& y9 m3 }7 g
my-row ;; the row of the intersection counting from the upper left corner of the d) l; d2 m$ A
;; world. -1 for non-intersection patches. w K' l+ _- ]6 A# u# l4 E& ]# G# _
my-column ;; the column of the intersection counting from the upper left corner of the
1 A% L* m7 N( j" [ ;; world. -1 for non-intersection patches.
" X- ^) V+ W1 C6 P O my-phase ;; the phase for the intersection. -1 for non-intersection patches.3 b7 \0 g: r& d' w4 N9 U
auto? ;; whether or not this intersection will switch automatically.1 T- P1 O ^% j2 w6 n) \
;; false for non-intersection patches.' M6 \" G0 Z' w4 a2 V4 n& `
]
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3 h: |/ r8 Y5 t- J3 L;;;;;;;;;;;;;;;;;;;;;;- G/ m9 E" g; P3 {/ u
;; Setup Procedures ;;
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# n" [1 p+ j: S: l# [;; Initialize the display by giving the global and patch variables initial values.
) t6 y2 p$ a5 e7 \( c0 u1 Q1 H;; Create num-cars of turtles if there are enough road patches for one turtle to
5 f. B5 A F6 Z8 N& c: f0 [/ g* Y @/ D;; be created per road patch. Set up the plots.0 q2 s4 k% ^* A1 q
to setup! F/ R: T# e) ~% @ J0 F1 b) l3 K
ca
7 }9 w. B" u/ x% C' o$ P4 k( Y0 W8 J setup-globals2 P3 c* F) N$ M& a1 U2 }
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;; First we ask the patches to draw themselves and set up a few variables# W& M2 E/ f- ? B$ |
setup-patches8 `. T5 {; N) W [
make-current one-of intersections
2 ~" Q+ B" X" l9 I0 `( r8 ?3 E; B label-current2 k8 ^6 c- g/ e$ s; I3 w8 K
5 e6 A+ `! b$ Y2 `; P G set-default-shape turtles "car"/ ]3 K# r: |% x4 f0 f0 E2 b
8 J* J8 b/ L/ ~6 M s) p if (num-cars > count roads)
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2 a5 V3 {2 B2 {& Q+ P/ F& c user-message (word "There are too many cars for the amount of "
) `) F5 m/ B8 o. f "road. Either increase the amount of roads "
. ~* q- u/ m* L @+ _# `( g5 n "by increasing the GRID-SIZE-X or "/ s' R( n. s% w/ W2 c8 w& o- S
"GRID-SIZE-Y sliders, or decrease the "
/ X9 u4 m9 A& j "number of cars by lowering the NUMBER slider.\n"
5 l9 y; k/ S; R. y: Z) b6 b "The setup has stopped.")8 J( v) g4 O$ {
stop2 ~% W9 u1 h: B! g5 G7 O3 T
]
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color' a& z$ L. C. l! {% d2 Y
crt num-cars d) y$ H2 k8 D r
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setup-cars
8 h7 z' E2 @; _0 B: f set-car-color! T$ y* z7 T1 N% c. d5 q* Q
record-data7 P) m: [8 K9 ~! |% n
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;; give the turtles an initial speed
H4 c* C5 ~$ r1 T1 s) m ask turtles [ set-car-speed ]
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! H- I+ i2 P- \ reset-ticks: R9 V3 W$ X: h1 Q$ G( b8 D9 u
end b& u K: E* A2 X( \4 W
* n9 {: R* V) q6 v. A A' K;; Initialize the global variables to appropriate values
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. D5 h9 ^6 C, G8 r! o. x set current-light nobody ;; just for now, since there are no lights yet4 }+ t: R# F6 H9 x
set phase 0) r8 J4 e( N9 K1 Z; \$ _$ |- u
set num-cars-stopped 0; N8 T# C+ X! w. T+ U' L, m
set grid-x-inc world-width / grid-size-x+ [ }) T& ~( H7 c/ Y/ Q9 i
set grid-y-inc world-height / grid-size-y! a, C0 F7 i( k0 q6 U3 C( m" \
. M" Q v% a9 y" A c ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary5 p0 ^0 v8 \7 R+ l. v3 ~6 _, D
set acceleration 0.099
/ Q* v9 c) l2 @0 F) N: @end
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& |8 o2 k+ k- z8 z;; Make the patches have appropriate colors, set up the roads and intersections agentsets,2 D, y2 c0 j% A% c2 b
;; and initialize the traffic lights to one setting* g( _6 D5 W! a! f" [* }
to setup-patches7 C/ X/ P1 H5 b# s& `
;; initialize the patch-owned variables and color the patches to a base-color
3 m# H+ A& `) s' u) B4 S7 u z ask patches! D! s3 S- m9 E$ j4 U
[
8 C9 z' ?( Z' @5 ^) X) D' Q! @ set intersection? false
" Q, p# Y- P, p1 P/ {) U7 @ set auto? false& n" P. p% D; ]9 S. u# Q, t) S- w
set green-light-up? true
9 H/ q M* {5 G$ _ set my-row -1
* b+ D. o$ g, P7 O$ H0 c4 L set my-column -1
6 |' c9 p2 t2 ~" x9 x z set my-phase -1
4 h5 I& d6 I: y A# A7 f set pcolor brown + 3: d6 M8 S; T j+ |
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;; initialize the global variables that hold patch agentsets k7 z9 F. _) r& u& y( g; k ~
set roads patches with6 l1 `- _1 @& \0 v& c0 b j& n% }
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or8 y% o9 j& T5 J! a1 h0 \
(floor((pycor + max-pycor) mod grid-y-inc) = 0)], ~# I4 P0 O) y* L
set intersections roads with
& I# w6 r: @5 r3 K/ ^ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and- U+ E6 j8 [' O& b. b( Q
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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& t& S% a! J* o0 y# l3 \% [, D其中定义道路的句子,如下所示,是什么意思啊?' `; U& Q8 K; |* M' P" r4 @
set roads patches with/ p6 b; T4 y' R' u8 b1 m) g- M
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
( r/ i! t* A/ V+ N9 q2 E (floor((pycor + max-pycor) mod grid-y-inc) = 0)], G9 G8 C; B4 W) d5 Y/ W
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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