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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。
2 z' l1 y4 t3 A$ G" M4 O0 t0 Wnetlogo自带的social science--traffic grid这一例子当中,2 {/ P: J4 q$ f: E8 y) q
globals
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/ b+ l( G5 c2 | grid-x-inc ;; the amount of patches in between two roads in the x direction* W( X5 Z h0 f% k: M5 ~( z
grid-y-inc ;; the amount of patches in between two roads in the y direction
) o! Q* [- k" w. z acceleration ;; the constant that controls how much a car speeds up or slows down by if) i. ], H1 T! _, G2 W
;; it is to accelerate or decelerate8 y1 C3 x6 a) P% V# o$ A1 w, h- v' d
phase ;; keeps track of the phase) ^. I$ R. ]' ^% S2 X( e
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
% C. I* j) W4 |# Y current-light ;; the currently selected light9 y7 {9 U& p7 _" t: p
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;; patch agentsets) O: r* T& w7 _# o& m5 }
intersections ;; agentset containing the patches that are intersections
# H- G& x ]: W6 d; p roads ;; agentset containing the patches that are roads
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2 b9 P0 R! K, E6 t% P& ~: ~turtles-own
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speed ;; the speed of the turtle2 B# M. r3 a( r" m5 a% G
up-car? ;; true if the turtle moves downwards and false if it moves to the right9 d& w2 `( X8 M/ e
wait-time ;; the amount of time since the last time a turtle has moved& h$ N* i: t5 a- k2 L6 j3 O
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patches-own
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- q; i% P9 w7 D intersection? ;; true if the patch is at the intersection of two roads
& @5 ^+ e( A) K" u green-light-up? ;; true if the green light is above the intersection. otherwise, false.
9 i- k0 @9 Q* i9 Q2 Z, q ;; false for a non-intersection patches.
# a# n9 e; t8 x) e6 ~* Z my-row ;; the row of the intersection counting from the upper left corner of the
$ R: n7 s2 v6 K9 \ ;; world. -1 for non-intersection patches.7 `& q2 ]+ Q& U6 u) t- L" d9 N4 g
my-column ;; the column of the intersection counting from the upper left corner of the
! x" I. h* i3 _8 m8 R) E) @7 s ;; world. -1 for non-intersection patches.
1 t: M/ }4 {+ B! Q* K2 U my-phase ;; the phase for the intersection. -1 for non-intersection patches.
8 N' O7 F% a8 t6 m" C auto? ;; whether or not this intersection will switch automatically.
4 J# }9 w/ f6 T) S3 B4 v ;; false for non-intersection patches.
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+ t( M& P/ B5 u0 D. M;;;;;;;;;;;;;;;;;;;;;;
) k4 I6 Y2 K* K;; Setup Procedures ;;
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1 W" H5 z7 I& H, |/ Y;; Initialize the display by giving the global and patch variables initial values.# C3 d& F, j; Q, O t+ o6 G5 C
;; Create num-cars of turtles if there are enough road patches for one turtle to
# I+ k8 P. m& e$ O+ [" \( G2 O;; be created per road patch. Set up the plots.8 H; D! `% ?/ n) n/ o( c# Q
to setup
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* Y* |( |! c- O6 y0 k* @ setup-globals
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;; First we ask the patches to draw themselves and set up a few variables% T3 I- L- ?" s2 D- G
setup-patches/ ], K+ b4 b/ a n2 H8 v
make-current one-of intersections7 x! {4 J1 `( @( `4 |# Q
label-current4 y: @) { N% q$ j; T% z7 M
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set-default-shape turtles "car"
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0 Z, C' f% }9 Y7 A, A; v if (num-cars > count roads)0 q) V$ ~) Q4 H3 w+ h
[
+ z1 o A3 M6 s& u user-message (word "There are too many cars for the amount of "
, b) V: j; X3 g1 e) I3 R) y) y "road. Either increase the amount of roads "
4 z! j+ J' n& T) ]# b1 p "by increasing the GRID-SIZE-X or "5 \5 ^: e, @: D1 p& M. \
"GRID-SIZE-Y sliders, or decrease the "$ l$ ~* D0 k% p; Q6 J
"number of cars by lowering the NUMBER slider.\n"
7 t3 k* g+ N) [% }% r8 ]4 y; K2 v "The setup has stopped.")
' e% z1 T4 g8 n" G stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
9 ]) [7 |5 \: x( _/ k4 q9 p+ V crt num-cars
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' d. F! U7 T z5 v2 U setup-cars8 k7 R7 S: A: N0 U6 {
set-car-color9 E" l' V1 ]" E
record-data
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8 `1 N$ I/ p, D& y0 C ;; give the turtles an initial speed
% _% L+ }/ _% a% S& H* X- A1 z ask turtles [ set-car-speed ]
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reset-ticks
0 f1 K( H. i/ }* Yend
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2 s" s, D2 H! j! V. M;; Initialize the global variables to appropriate values3 _ s2 n. V2 m j9 f
to setup-globals) I/ c2 R! r9 m2 ^
set current-light nobody ;; just for now, since there are no lights yet. _, V4 K: K) s3 s- ~* t* K
set phase 0
& V% E x! y/ w3 G set num-cars-stopped 0' l9 m6 x& { E- ^% M; h
set grid-x-inc world-width / grid-size-x& q7 k& d5 u; K+ p$ T
set grid-y-inc world-height / grid-size-y
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- q8 w$ Z/ e6 m& f0 ? ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
: @) s( G" h9 m6 m. k V set acceleration 0.099. d7 O& |: s/ F: O- i6 o! M* k$ V# Q
end1 E+ S+ j: ~- a" B- N
+ q7 U* p+ d( H;; Make the patches have appropriate colors, set up the roads and intersections agentsets,9 P$ i) {# {/ i6 h
;; and initialize the traffic lights to one setting6 n% _- j/ k P3 q6 d2 E$ G% Z' Q
to setup-patches
4 \. D, P2 Q% D" k- y; y ;; initialize the patch-owned variables and color the patches to a base-color& @- q" [2 g7 q8 r% B
ask patches
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set intersection? false2 z+ Q" j% K0 i4 R: y! @9 k" y) t( K8 b% L
set auto? false+ q. ] A2 z. P8 }: X3 U- L. K
set green-light-up? true
/ C9 O$ T* E; Q9 }* ~) m set my-row -1
& s. _9 s4 y1 [ set my-column -1+ D% e+ `0 c) [3 z6 i
set my-phase -1& k2 a. Z; W$ Y; I; I+ f# E" c
set pcolor brown + 3
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/ t+ w0 _) t5 q% }! o ;; initialize the global variables that hold patch agentsets4 s V# ~* W0 m, V
set roads patches with& `' f6 \ `4 o' I
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or8 B# d0 @0 H6 N% L; l; A, z1 a+ o
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
" K. C9 {3 W& ^& ~/ K set intersections roads with9 w, }/ W' a9 o8 ^4 K, K
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
: I& D! D9 U9 Q. p" P! V5 L; o (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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# I8 o2 J& d7 _8 ~$ { ask roads [ set pcolor white ]! K4 N' q7 n) D( v1 Z
setup-intersections0 ~# Z5 @: @: @( C
end1 Z- `3 ?0 Q& _% A0 D8 _
其中定义道路的句子,如下所示,是什么意思啊?
( z, Y* i- P, l% _1 z) z set roads patches with
/ u1 @% |2 ~0 [: b) a& d! @ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
. q+ o, J6 C W- N# S) E. _ (floor((pycor + max-pycor) mod grid-y-inc) = 0)], T! O7 L& [& Q0 G. A( \: J8 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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