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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。 a' p6 \4 J$ Q, D
netlogo自带的social science--traffic grid这一例子当中,% z; l& p/ k. t7 W; [/ X, w" R0 a
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction8 [; K7 U8 D+ V9 x" k. g7 R
grid-y-inc ;; the amount of patches in between two roads in the y direction2 D$ n: }6 B" ?
acceleration ;; the constant that controls how much a car speeds up or slows down by if
+ n0 `# Y% S8 l ;; it is to accelerate or decelerate
: L8 a( |5 ~! v+ Q$ b: ] phase ;; keeps track of the phase
* E/ N# Z/ n3 N" N# ^' V$ u num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure/ a+ S; r- l- |% ?
current-light ;; the currently selected light, V" ]' W8 k: }& ~0 H
: Q9 F1 F n* g4 \. T' {* ^ ;; patch agentsets
( E+ B, n, ~; ^- [8 ~ intersections ;; agentset containing the patches that are intersections
L7 D; ]$ `8 p. G3 \ roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle
4 y6 d% c- \+ A# W+ R up-car? ;; true if the turtle moves downwards and false if it moves to the right
! M$ r. u, G% i, l: V) I- U! _ wait-time ;; the amount of time since the last time a turtle has moved
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patches-own f8 f1 e7 W B2 V. C! Z* N
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# F. M g: y, t' d; ~1 }7 ? intersection? ;; true if the patch is at the intersection of two roads+ Z/ {7 Y7 Q& v% }
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
6 O y% w$ l* `' }1 P) K ;; false for a non-intersection patches.) a" M4 N4 ?# X! b1 ^
my-row ;; the row of the intersection counting from the upper left corner of the
+ L! @$ M/ Z+ X4 |. R! N- u8 C8 S% ^ ;; world. -1 for non-intersection patches.( I& S1 |/ f0 m! m ?0 e; `$ c
my-column ;; the column of the intersection counting from the upper left corner of the
; V) M- z% z6 N4 c ;; world. -1 for non-intersection patches.
7 r6 }# D- o! ]1 v6 Z c my-phase ;; the phase for the intersection. -1 for non-intersection patches.* Q/ F4 |. U$ b$ e
auto? ;; whether or not this intersection will switch automatically.$ J8 r: k/ B# L; T& R
;; false for non-intersection patches.- [7 h' Z- e& G$ N( V
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$ C3 u' S; w+ h9 e;;;;;;;;;;;;;;;;;;;;;;5 _) p( O+ a: j) u$ j8 [9 D
;; Setup Procedures ;;
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9 H( y# [+ z+ k;; Initialize the display by giving the global and patch variables initial values.+ {) A9 S3 N a8 j- L
;; Create num-cars of turtles if there are enough road patches for one turtle to
8 q2 f1 I8 b) Z$ n' _3 S& t;; be created per road patch. Set up the plots.! ~( m: N0 r! M3 h5 w2 _; K, a
to setup
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setup-globals; a& c, r9 g) y, Z# [
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;; First we ask the patches to draw themselves and set up a few variables
( f. `2 l3 P& W/ w7 ?& w, @ setup-patches
& a$ \7 l, V0 a% Y7 r) s# T) @' H make-current one-of intersections* y3 a. P! W3 M, i. c' k3 _* r
label-current
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& ~6 Y& j$ b |. [& R# ]/ q set-default-shape turtles "car"
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X) C" b( S7 N) x3 ?- v7 M# c if (num-cars > count roads)
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+ H k3 g) E+ S( n user-message (word "There are too many cars for the amount of "' ], {& P1 W" ]9 r! A% O
"road. Either increase the amount of roads "
* g0 E$ s _$ @+ I& }+ N "by increasing the GRID-SIZE-X or "
/ p- }" g' b3 A: A" ~0 t6 } "GRID-SIZE-Y sliders, or decrease the "
6 e4 g8 Q/ |% j( _! M$ G "number of cars by lowering the NUMBER slider.\n" H5 J$ g) p+ m. z
"The setup has stopped.")
6 m9 W, a6 Y# H% v' d! l8 }9 C3 e7 g stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color+ X. f) P/ @. f* _2 K
crt num-cars, R) g- r' W, u. k. s3 q
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setup-cars
6 ^) P8 J6 H) u2 A- G+ b4 D" m9 \, I set-car-color- f8 H: S$ E# ^# C; U \- ?- d
record-data
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* Y! x* E% Q4 S* z0 x7 w ;; give the turtles an initial speed9 O7 |6 Q6 n6 E) g" {- d6 x
ask turtles [ set-car-speed ]
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reset-ticks
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;; Initialize the global variables to appropriate values
: z/ p' ^0 X. g4 ~+ u& ]$ Oto setup-globals
' e S* Q, |, @) P; M( x set current-light nobody ;; just for now, since there are no lights yet
2 g$ ?0 F8 q2 n! V$ p) ~/ x' v. B set phase 0! A& ^2 Z y5 h" {7 g$ ?7 X R0 U
set num-cars-stopped 0
. n5 S6 o; s' R set grid-x-inc world-width / grid-size-x
9 \$ ?4 z5 P8 U- b; j set grid-y-inc world-height / grid-size-y% b- E8 n5 s/ v/ A+ d- |
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
6 D+ ^* Q# Q' H' I7 L2 v+ j set acceleration 0.0998 l4 q8 C) K: L, [3 ^; E, `. a
end2 f" a; n: C5 Z
- P x) G+ w0 f;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
8 W4 ]& a3 |+ x, O9 g;; and initialize the traffic lights to one setting
% M- H- t8 Z2 g* tto setup-patches
/ ]/ `& s. F0 e) y8 h ;; initialize the patch-owned variables and color the patches to a base-color1 y) c# O7 @& _/ t0 N' ~8 ?7 [
ask patches$ w8 u9 H" a* z8 j# P. G$ S
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# `0 M$ E+ Q3 Y- I set intersection? false
5 m8 P- n2 V$ ^" Y" S* D" l5 Q set auto? false
* h3 j( v) E4 \, ~ set green-light-up? true7 v+ t' d, a5 E, Z% T: ^- T
set my-row -11 A" [" i; }/ N% o
set my-column -1
P% q; s7 g- s set my-phase -1# p+ w) `7 L; a
set pcolor brown + 3
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* e* b+ a- b( I9 u ;; initialize the global variables that hold patch agentsets
) T2 Y5 b2 q% z set roads patches with
( r4 D8 R6 c$ ` [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or0 x" X8 k( Z" K7 L1 z# g0 B
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]# c# _5 C. b* c* B! N
set intersections roads with
. S/ m2 }+ n+ C [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
" z9 W3 M5 b) `) P0 H( b$ h (floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ o6 B8 ~2 `* B5 j
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ask roads [ set pcolor white ]
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end) ?0 E! L- E& L* U% }* g2 B W
其中定义道路的句子,如下所示,是什么意思啊?
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
C2 [% A3 D Q5 P8 |3 r% U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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