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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。& f: t# B6 Q. A5 s! X
netlogo自带的social science--traffic grid这一例子当中,* z6 f( w3 O7 O: d2 E' s
globals+ w" M7 x0 Z. ?7 B
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grid-x-inc ;; the amount of patches in between two roads in the x direction
2 b( ~+ Q( u' O. P& p6 J( {, S" ^& L grid-y-inc ;; the amount of patches in between two roads in the y direction
! @5 |3 D7 k; E2 L, i' b acceleration ;; the constant that controls how much a car speeds up or slows down by if
, { Y q# v5 C2 G- I5 F' _/ x2 T ;; it is to accelerate or decelerate$ `6 Z8 S/ G+ t* N T& z; R% p
phase ;; keeps track of the phase
% x% [+ n. H1 M% l9 E! U# @& e6 ` num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
+ I# o7 v6 ^7 f7 z' i. H current-light ;; the currently selected light8 T8 J, H) q. P6 y! }8 G+ q0 h
) Y# q; O3 ^1 X2 [1 |7 |* A ;; patch agentsets
+ [ z- [2 \/ M1 g intersections ;; agentset containing the patches that are intersections
, ^6 ]0 z' K2 I: f$ z' V roads ;; agentset containing the patches that are roads
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turtles-own( n; \9 ~2 Z0 X9 ~
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speed ;; the speed of the turtle, M6 L5 x& i: H3 }: J! `2 [
up-car? ;; true if the turtle moves downwards and false if it moves to the right
3 A/ ^! o6 ]; y5 ]8 p4 g* T1 ^ wait-time ;; the amount of time since the last time a turtle has moved: M+ C/ a2 P: Y- ^: o! ~7 U) m
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# a2 j4 }2 A2 g* H" bpatches-own4 B! a j: j5 _5 q ~% t
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* y( y& w) r3 B& w* x intersection? ;; true if the patch is at the intersection of two roads
{# M; a6 f5 j9 q# u! H green-light-up? ;; true if the green light is above the intersection. otherwise, false.
0 F- p) }0 P$ } ;; false for a non-intersection patches.
5 b+ V ~/ W6 {5 r, M my-row ;; the row of the intersection counting from the upper left corner of the% g, g7 ~' t8 k+ E9 ^
;; world. -1 for non-intersection patches.
' z! F* J% u* a3 T/ p4 U1 V; w5 Z my-column ;; the column of the intersection counting from the upper left corner of the
+ h3 k1 A/ S& A& t) P5 f! I ;; world. -1 for non-intersection patches.
; q, U% Q: D7 G6 p- R my-phase ;; the phase for the intersection. -1 for non-intersection patches.
- y. r* |1 L8 p! e. T auto? ;; whether or not this intersection will switch automatically.
% ~0 S% E, H% p. y' Q; W ;; false for non-intersection patches.
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0 `+ P' g3 P! L! d0 h;;;;;;;;;;;;;;;;;;;;;;
: c0 v2 H7 A8 q/ ];; Setup Procedures ;;' O& Z/ P. K5 n: |+ W; v+ Y
;;;;;;;;;;;;;;;;;;;;;;
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4 O9 b9 b, s% p; Y4 }* |7 _3 q! G;; Initialize the display by giving the global and patch variables initial values.
& N9 `8 A' @1 z;; Create num-cars of turtles if there are enough road patches for one turtle to
1 n% z) f9 d, ^: s% ~7 T8 N;; be created per road patch. Set up the plots., L7 `* g! q* j- W
to setup4 i3 q s' l! {% y* g
ca
; X/ [. {6 x$ Y( L0 A: w' x setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
7 C* E% ~3 X4 ~) Y" g9 y6 { setup-patches
5 R& k; |- z* Y$ D make-current one-of intersections
+ z. ^" D! l* T5 h4 y% q1 X9 A label-current; O' \3 W8 t; y
5 R4 f* C& w' o) s* U- _1 v" j set-default-shape turtles "car"
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
0 W y# W6 c, W( Y "road. Either increase the amount of roads "
$ l+ j1 @) Z) X5 w+ R1 K' J "by increasing the GRID-SIZE-X or "
& `" @( M" O( f& s "GRID-SIZE-Y sliders, or decrease the "6 j0 E h3 c6 D5 l! o- u
"number of cars by lowering the NUMBER slider.\n"
: n6 V. d* D# X3 i0 a5 z "The setup has stopped.")3 J) H( c9 \/ U! X" T# }- o. }/ }
stop9 s3 v: i! Q+ C7 w0 {
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
- F9 ~! w+ d: s" Y( i crt num-cars( u+ e! i v% t" X
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setup-cars0 G4 U2 n# g1 Z$ O. F8 q, i
set-car-color! M1 J, G: C6 x. g& i
record-data% Z7 u/ @9 Z1 A6 D8 Z3 Q
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4 H; r$ _! z, C/ x, O ;; give the turtles an initial speed
. K& ?) }2 `/ \% K, m' S! N1 {9 u ask turtles [ set-car-speed ]
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reset-ticks) Z/ f3 L$ q" C+ Z) [& O3 t4 ?
end
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( [( o# p1 W4 g;; Initialize the global variables to appropriate values! o4 }( [ G* W/ _, a! D
to setup-globals
4 O9 ~6 i( e, ?/ Z set current-light nobody ;; just for now, since there are no lights yet
+ O$ m5 M: r& {, b4 z5 M set phase 0
/ }% m* A7 [' @7 u1 E1 c' O4 j set num-cars-stopped 0
4 b$ f' D+ x* R set grid-x-inc world-width / grid-size-x
0 c7 ~% i! p. ]6 Q7 r5 a 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
5 X3 j, Z% m4 G+ F set acceleration 0.099
% w9 q: N7 n( y2 o+ V- bend
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3 l, @9 Q6 J( l;; Make the patches have appropriate colors, set up the roads and intersections agentsets,# x6 f, V1 Q7 C* J$ w
;; and initialize the traffic lights to one setting5 A3 `; ^7 [" w6 b' l" H9 i
to setup-patches. _6 v7 F1 N& ~3 L1 O, V
;; initialize the patch-owned variables and color the patches to a base-color
- \: |6 l) V5 b- e ask patches4 R/ q" m) E1 b) O! X% [6 S
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set intersection? false
& ~* L( Q, q( o* X* _ set auto? false
5 |( K7 i" {9 s set green-light-up? true/ j; m$ m3 B/ T& D; M9 z# Y
set my-row -1, U3 w8 x' [) s& F/ b" i3 h& ?
set my-column -1
6 @* R6 k* I0 [' |# \8 S( u set my-phase -1
% m9 c1 T* ?3 g7 E1 k+ R set pcolor brown + 37 E) z: n, t, N9 E6 x; `6 E: M
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;; initialize the global variables that hold patch agentsets
$ {& [9 a& V8 ]9 U) P! @ set roads patches with
; V% k* q( U: ]8 t0 L% r [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or0 X3 L& F! l1 I; c) G& F( i* }
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 f/ e/ B) D: L1 F/ C2 E set intersections roads with: J7 H2 d! D0 r/ f
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and3 U1 W& K. z$ K+ |6 Q8 f
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 U7 X0 c2 s3 p' {' S
0 {: p: i/ u9 ~/ h! D ask roads [ set pcolor white ]. I- t" U7 Q/ w. J: [
setup-intersections, Q: [! A6 n9 S, Q
end2 V3 w8 H1 v6 U* W4 U- p
其中定义道路的句子,如下所示,是什么意思啊?
) [" @+ L* k( n* \ set roads patches with t! Y/ B O3 U' Z
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
( Y ]( u' J/ g6 O1 O' N8 ?4 B (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 ?1 }, \0 J W8 v% D1 X' ~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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