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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。- {# B9 Q$ n: h6 `0 }
netlogo自带的social science--traffic grid这一例子当中,
8 d4 X5 Z! h4 w5 R. Bglobals; n# W# G2 a* s4 A' w5 m4 s, i/ }% ^% V
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grid-x-inc ;; the amount of patches in between two roads in the x direction0 ~2 P7 ^8 O/ h* M
grid-y-inc ;; the amount of patches in between two roads in the y direction: `0 v! R# l7 g: l8 R/ F
acceleration ;; the constant that controls how much a car speeds up or slows down by if
; r/ @0 `. C t; f2 @! b4 f3 n# R1 n+ }, x ;; it is to accelerate or decelerate
* k; f. a" R- ^3 c7 e. o phase ;; keeps track of the phase' p1 t) F! a% V; ~1 r" |
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure' z/ {* Y, m: p
current-light ;; the currently selected light
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. H; d' C) z# v1 P" V M3 E) R& p ;; patch agentsets; w- Q/ T7 M1 B
intersections ;; agentset containing the patches that are intersections0 Z! H) G7 g4 h5 z
roads ;; agentset containing the patches that are roads
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turtles-own" m8 M% u, o: Q$ t) {
[
! U) v- d. ^" X! |9 N' C1 _ q' D speed ;; the speed of the turtle
" F3 ~( b7 P6 N: ^0 ~ up-car? ;; true if the turtle moves downwards and false if it moves to the right' b. `# z- V o
wait-time ;; the amount of time since the last time a turtle has moved' n9 z, P4 f$ f! \4 Q7 Y
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8 v" I, E9 T5 Q1 @& M$ e$ N/ tpatches-own' u8 e. ^8 q6 f2 @9 _
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intersection? ;; true if the patch is at the intersection of two roads
@0 `$ V) x P4 w% b0 ` s7 A green-light-up? ;; true if the green light is above the intersection. otherwise, false.1 ?" O/ v) A- e! z
;; false for a non-intersection patches.2 U3 Z0 C1 V: k6 Q+ u
my-row ;; the row of the intersection counting from the upper left corner of the- ]( F% n( a# W( w
;; world. -1 for non-intersection patches.- f4 \5 B8 V/ x
my-column ;; the column of the intersection counting from the upper left corner of the8 Q( G; t: ?+ ^" C7 X
;; world. -1 for non-intersection patches.8 k" }9 V8 a5 f3 K% {* I
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
! \$ _# g% j4 h8 \5 G$ J) R auto? ;; whether or not this intersection will switch automatically.# c5 P4 @/ g+ x0 K8 ], a, ~
;; false for non-intersection patches.: `/ M9 }4 {2 l+ O
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;;;;;;;;;;;;;;;;;;;;;;
8 [- L: V; Z, Y" ~* V6 s;; Setup Procedures ;;
* W" T, P$ |) _( S1 E% x' F0 f;;;;;;;;;;;;;;;;;;;;;;
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- z6 v) U) ?7 u1 O;; Initialize the display by giving the global and patch variables initial values.' z! x$ B- N$ p9 {) `8 R+ A: S1 _
;; Create num-cars of turtles if there are enough road patches for one turtle to, j7 \' n( M2 y
;; be created per road patch. Set up the plots.
7 e& S; k6 \: U: r9 x1 Ato setup
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& `2 V7 j0 P1 R' N: i1 V- o setup-globals) Y: N3 t2 G. Y7 x1 d& M+ b7 U8 e
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;; First we ask the patches to draw themselves and set up a few variables
2 h( I# }! A) S4 e U setup-patches1 D2 ]) C' E* b3 f% \6 S/ \
make-current one-of intersections* ?% q* z2 ]" U9 N& E
label-current
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6 g$ M7 x6 ^0 F set-default-shape turtles "car"
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. N/ G/ f0 r% ]5 {4 k if (num-cars > count roads)
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; n$ C1 g e! R" }; x. }, g user-message (word "There are too many cars for the amount of "
5 a" w/ i5 v9 E/ z "road. Either increase the amount of roads "6 H9 p" g% ~) E; d) ?+ _
"by increasing the GRID-SIZE-X or "6 L* d6 S. K5 M' Z5 d) `& a' i
"GRID-SIZE-Y sliders, or decrease the "
" i; U* t+ J( a3 y, u "number of cars by lowering the NUMBER slider.\n"
5 l/ X5 P1 \3 O% B0 y7 K) E2 X1 q "The setup has stopped.")
& g: V" s% w3 }. C) `5 q/ O stop
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) u& j! m8 n b2 x9 m" n ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color$ d+ U3 C4 e$ M2 P) }9 Y" w8 L% k
crt num-cars$ T) @. m1 v/ _$ |
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setup-cars
3 N3 J' O5 L3 y, M+ u8 P set-car-color
- \) ]5 U5 \9 w9 f record-data/ g4 u1 {7 Q! r; r9 G" F
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0 ~, j: {# ~9 C! T ;; give the turtles an initial speed. @" B7 f" q4 f% ]& C, K
ask turtles [ set-car-speed ]
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reset-ticks
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;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
, S' j, _$ w) A& J6 l; E set phase 0
% n) b1 S0 [0 w$ }+ M set num-cars-stopped 0
) ~' _7 G3 G/ D! J+ f set grid-x-inc world-width / grid-size-x) @4 ?, \$ a9 Q& U6 a
set grid-y-inc world-height / grid-size-y7 V, F. _8 h! v* V6 O7 U
) W5 ^1 }: I: X. g ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary: f. b* V7 f; E ^5 S
set acceleration 0.099# f4 J1 M8 r% p9 R
end. ?* y+ p0 R9 ?' m! N- I* X( O$ R/ t
. j* o- W$ u5 z3 t8 S/ k;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
# y1 C, d* R! y( r3 _1 w& @;; and initialize the traffic lights to one setting
0 c% T' u8 V% Z$ T* N0 _! j# sto setup-patches
4 [& X8 Z, G/ K, q ;; initialize the patch-owned variables and color the patches to a base-color
5 ~+ a2 ]- i% Y# F- a/ M ask patches
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set intersection? false
; S1 ]/ F% y% R- g; l! P9 c set auto? false
# r2 F! I% T( d/ W# J set green-light-up? true
" J6 Z+ i/ h5 L set my-row -17 W. t. R9 C/ n, h* e6 \
set my-column -1
; p2 x I _; I) N set my-phase -1
% R8 T/ V* Y7 P set pcolor brown + 3
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% l5 V& H l+ U ;; initialize the global variables that hold patch agentsets
6 \; L( R5 H6 K6 O, q. i0 f# }3 x set roads patches with) j$ U) ]6 j b# k$ ^; X* B2 }2 E
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
9 Y/ {9 }; w, N) N7 E (floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 J' m+ r! K5 a% S% Q
set intersections roads with
/ b* [% a1 ?/ Z1 l3 t$ } [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
# {, Q4 H$ M0 }" H" a( ~ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]- y/ p, R# \; C5 u
setup-intersections$ c: ]; x8 [ l1 Z( a9 c, s
end
' M0 N/ q9 W5 |: }) A/ e8 c其中定义道路的句子,如下所示,是什么意思啊?! v6 c' h {) Z+ Y" B* j
set roads patches with0 {8 w' w( V, ]
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or7 N( Y& s; U: _0 I) z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 d6 l* B! \" l5 J6 n# p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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