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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 \9 W6 u1 A+ G% z9 ?netlogo自带的social science--traffic grid这一例子当中,5 p5 N- R, H `' Z$ c0 P$ |+ V
globals$ B0 Y* q! i1 `! k+ a% e6 d% j
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grid-x-inc ;; the amount of patches in between two roads in the x direction
/ s; A" E- B" X2 U grid-y-inc ;; the amount of patches in between two roads in the y direction- z2 }( L% i0 O0 p5 {( e
acceleration ;; the constant that controls how much a car speeds up or slows down by if
) N" u; L Q/ {( u ]: Y ;; it is to accelerate or decelerate! {" [1 v- l7 F( j
phase ;; keeps track of the phase. w- K5 Y7 y" Y% O3 _* b
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
& p' f8 Q0 G% j& l( k L! q7 v current-light ;; the currently selected light4 ~7 N7 U3 ~8 Q$ o0 F% f1 ^
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;; patch agentsets. h1 \+ b. O1 x' K/ |' O( Q
intersections ;; agentset containing the patches that are intersections& Z8 B/ g9 ~8 I3 I% F2 K
roads ;; agentset containing the patches that are roads
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2 ^! C7 e5 }* L% \# i: Kturtles-own" u7 r+ F+ [- c* S5 z9 P5 S' E% G0 S
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speed ;; the speed of the turtle" V% A* t9 E2 I4 K$ Q X$ N
up-car? ;; true if the turtle moves downwards and false if it moves to the right# y/ w. o% d1 h3 z) H7 K6 T! q
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own; _: U: R) |+ e" o# b
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intersection? ;; true if the patch is at the intersection of two roads$ o8 H- U6 L7 ^' l: O
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
7 y6 @7 g; f8 c4 W* u$ V ;; false for a non-intersection patches.3 w: x% A& a0 Q5 i2 |+ p
my-row ;; the row of the intersection counting from the upper left corner of the9 |" |+ M4 b7 z
;; world. -1 for non-intersection patches.
5 F9 `7 `/ N/ }4 {7 I my-column ;; the column of the intersection counting from the upper left corner of the2 F; ^: H6 [0 b% Y! @" s
;; world. -1 for non-intersection patches.
7 Z( v! m; V o. v# S my-phase ;; the phase for the intersection. -1 for non-intersection patches.
6 K: r9 c6 q( l6 W2 @' w) r" O3 k& z auto? ;; whether or not this intersection will switch automatically.
! ~3 a9 u. b' U5 b% v# { ;; false for non-intersection patches.
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. F6 S- d& @; A$ z$ y;;;;;;;;;;;;;;;;;;;;;;# m; V/ v+ n4 E$ U. ^5 D4 m& J7 d
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.8 t/ Y3 o- ^8 j9 k; @
;; Create num-cars of turtles if there are enough road patches for one turtle to
V$ Q5 v8 Z; ~/ U* o: g. b;; be created per road patch. Set up the plots.
+ N: \$ H% x# N- Lto setup
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setup-globals# \8 @" G9 ^, l; l9 R: i6 T1 R, l! @
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;; First we ask the patches to draw themselves and set up a few variables
/ w4 ~. x) w' _0 a9 J* F9 v setup-patches
N/ q2 I6 S& ~* {' |! j: K make-current one-of intersections
% `* N( d7 A7 e- { label-current7 |! ~1 O3 e% M8 f
* @1 Y6 B2 T5 W; y; m0 C3 M, t set-default-shape turtles "car"
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if (num-cars > count roads)" C1 r4 f% ?# [% q" P3 Q$ s) o
[
1 M# x8 r9 k- W P; ?" {. A4 r% a user-message (word "There are too many cars for the amount of "
3 F8 \$ f: ]( p "road. Either increase the amount of roads "
' M% ^' c0 P+ K; ^ "by increasing the GRID-SIZE-X or "' u) Z! v6 D2 y
"GRID-SIZE-Y sliders, or decrease the "
$ I) P( B$ f9 C) d; s% X: ]0 l "number of cars by lowering the NUMBER slider.\n"
+ q" P3 N v/ J$ Q "The setup has stopped.")% w. z& O6 i: R+ I
stop2 K5 d( J7 ? s
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
5 H2 N/ f; s" } crt num-cars
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, P4 M+ t5 q& {7 A2 a3 l/ m3 z setup-cars
1 e/ Q b1 p: t* ~# v/ p set-car-color
3 I2 d( N, K5 P, a$ E1 s# E record-data+ E) P8 ], Z9 Z2 f* K6 m
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;; give the turtles an initial speed8 a7 Z" ^# T# H" C
ask turtles [ set-car-speed ]- r5 ^3 @( }8 M+ w
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reset-ticks, O }. ?' R% d \
end
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, O& A8 |( d/ q T- K;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
: B5 x* w8 Q' B set phase 04 J/ ?9 g. C0 I+ F# e( {: ^
set num-cars-stopped 07 i0 s1 I8 w% e! `$ z# g
set grid-x-inc world-width / grid-size-x
7 z1 b9 e8 j9 V/ l set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary; G6 c& L! k1 P% j1 R% {7 A2 }
set acceleration 0.0992 b' O* [4 |0 c h: r: X, t
end
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+ E6 u4 o5 A- |7 N6 {7 ^7 o' x;; Make the patches have appropriate colors, set up the roads and intersections agentsets,! ?" d/ N) Z- v9 `" c! a: E
;; and initialize the traffic lights to one setting: N- P+ p! C) P; f3 q' m
to setup-patches& ]/ M+ h9 B4 u2 T
;; initialize the patch-owned variables and color the patches to a base-color/ N" ~. {2 y( t* W& Q7 o: q& J
ask patches$ l! u8 X7 ]4 O5 y7 T+ ^) r
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2 q0 \2 y' } n2 N set intersection? false
# o& y* j+ k/ l$ I/ e2 J set auto? false
; ~$ s( z- R1 `# r set green-light-up? true: P; d- w8 b; c9 b
set my-row -1
0 v; d0 |# z- ?$ N+ |) w! R set my-column -1
5 i2 e5 I3 f8 @( h. M9 D. F set my-phase -1
- W+ a4 k5 c }( x( h- r- {: { set pcolor brown + 3( q0 e6 B5 P+ W- a! @& [% f
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;; initialize the global variables that hold patch agentsets2 r) u! ]# Y8 [9 X- i8 ~
set roads patches with
9 _% Q+ u( [8 j# ]* y: m9 D5 \ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" s1 T2 i) X d
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
- M- u. F1 b: d set intersections roads with
* d) ]8 J. T7 t5 w( i [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and( _' \- ?" U; ~2 f
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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+ r& B: `& f# f9 A: z7 x ask roads [ set pcolor white ]% ]! Y; v, g. |$ v$ m
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?4 T+ Q1 }$ d& w; k) r) k0 s o8 |
set roads patches with; |: f) C4 R* [) n2 K
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or- @+ U( [6 M( | e9 f
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 B* ]2 h7 ^# h' u: A! ~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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