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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。- W8 n7 Z2 j2 V: q% `1 O6 U0 W0 P
netlogo自带的social science--traffic grid这一例子当中,: @8 _ d/ X6 L8 m4 P
globals3 G& d/ I# a7 u: ^
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3 V% ?1 G: X: d! b grid-x-inc ;; the amount of patches in between two roads in the x direction1 f) y( l* L8 v
grid-y-inc ;; the amount of patches in between two roads in the y direction
3 m/ F4 S& h- T/ R acceleration ;; the constant that controls how much a car speeds up or slows down by if0 i( c* ] } B9 d1 W' ^& h
;; it is to accelerate or decelerate
: A4 m) Z0 I. z& {9 e- [' c; [8 R phase ;; keeps track of the phase. I7 N3 |& M Z& s+ [/ _
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
/ c1 T, i( I) b) a+ Z# F7 P/ l current-light ;; the currently selected light' k: G7 H' R7 z7 n3 a2 |* u
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;; patch agentsets
# i. b8 O& Y! f' {0 O3 }+ A# K intersections ;; agentset containing the patches that are intersections
& P i& j) `7 I! @. i0 d& Q roads ;; agentset containing the patches that are roads0 P4 _" |9 k' U. Y1 K |! h
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' N/ D) n9 l2 y+ Y* m6 Pturtles-own' l9 i7 p+ o; H5 ~* e7 o
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* \! {; t' c& l* y" h4 z speed ;; the speed of the turtle
5 N/ ~: b3 a2 v+ N" \' x6 A4 B up-car? ;; true if the turtle moves downwards and false if it moves to the right; s2 Z( \' y* U6 o# t6 ~2 H' \: B
wait-time ;; the amount of time since the last time a turtle has moved) ]- V1 a" O6 `# j: x% o8 T/ n
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$ P+ \: W$ _( h3 G& A" Lpatches-own5 g# d" d0 r5 X7 h
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& T4 I3 s& ?3 |2 O/ ]/ z intersection? ;; true if the patch is at the intersection of two roads" F0 H( i$ Y+ v
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
9 I5 Y- J; x3 x$ m4 r ;; false for a non-intersection patches.
, W4 E' t1 U% c& W5 t( I my-row ;; the row of the intersection counting from the upper left corner of the/ l' k1 M( e$ ~2 @
;; world. -1 for non-intersection patches.
6 U1 J1 ~" _3 @8 U my-column ;; the column of the intersection counting from the upper left corner of the+ S' X" O7 A* S; @( M, b
;; world. -1 for non-intersection patches.+ L! L, X/ {9 O& W1 O, o: o
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
8 b1 W+ q: `& T auto? ;; whether or not this intersection will switch automatically.
4 s$ U, D; ~2 B( W. v ;; false for non-intersection patches.
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- p; x; Y5 Y" j: \7 K) v;;;;;;;;;;;;;;;;;;;;;;
0 ]1 J7 Y0 E( I* f$ N;; Setup Procedures ;;
- r! b" c8 Z& ?2 I+ e- M;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.0 P7 U) t; _! C( g' h0 W! V/ s, C
;; Create num-cars of turtles if there are enough road patches for one turtle to
# T" K/ F5 o* G" f& Y# d;; be created per road patch. Set up the plots.
2 w1 d' x: C2 Nto setup; {3 I) V" V- S @" G
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setup-globals) U9 L' X) f; X) }
. W, ~$ c1 O' { g6 u ;; First we ask the patches to draw themselves and set up a few variables
: e! X/ g9 T. v& {5 s- c setup-patches
- Q! w* T. N) } make-current one-of intersections) L* |: z/ Y+ U- w1 W/ S
label-current
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+ a) l) t, W, a9 E, l9 N, p0 @ set-default-shape turtles "car"
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if (num-cars > count roads)% K! ]. D( b: X
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user-message (word "There are too many cars for the amount of "6 h8 L; m5 P6 P" @& C4 [, h8 N* M
"road. Either increase the amount of roads "
5 L! l* w* E/ a3 B0 a "by increasing the GRID-SIZE-X or "8 R( j7 J- a6 |6 _
"GRID-SIZE-Y sliders, or decrease the "
/ \! `) u( @, }' Z2 d& k+ \ "number of cars by lowering the NUMBER slider.\n"
# V0 g' _1 `- s* T6 [8 D' q# d1 N "The setup has stopped.")
& w0 S& T/ G6 f% q) P; j stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
# G9 E+ V* h: e crt num-cars! Y* a9 C( L$ g/ |! @/ C
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* a, z o" L0 ~ setup-cars- i- P* O$ i( ~& P6 U0 p
set-car-color Q( D/ m1 E: M
record-data
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% T4 s/ o( g# p8 D1 ? ;; give the turtles an initial speed4 Z3 _# N- h; e3 \: ?" C
ask turtles [ set-car-speed ]5 x. R/ r9 ?9 T) X$ j8 O
$ `6 S( W- P5 ^& K8 ]& s/ A reset-ticks1 F$ A: O- G" Z
end1 d9 _0 k/ r% w4 P. @
$ v" w# K. `) A" A* v;; Initialize the global variables to appropriate values
/ b; x% n# H3 h% ^! |! hto setup-globals" L* a- L+ z1 y7 O5 w
set current-light nobody ;; just for now, since there are no lights yet
A5 {4 Q9 V9 }0 h! g% s* E& r3 j set phase 04 ?2 g* b* N1 H' |
set num-cars-stopped 0
- z& `* d. C+ o1 M3 c* j1 N set grid-x-inc world-width / grid-size-x
) C A, g1 V% ?+ }: _" n set grid-y-inc world-height / grid-size-y$ F' U& i9 J8 I- V/ F% m2 M9 p" {
7 d2 l$ c3 }$ \" X ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary) {+ H% b8 g* O \; ~
set acceleration 0.099% J8 C+ B% o$ Q1 q% {; n6 P
end
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4 l+ e1 F- D* D8 S7 C9 {& b;; Make the patches have appropriate colors, set up the roads and intersections agentsets,/ y6 [6 [( _1 L5 I
;; and initialize the traffic lights to one setting' s# A! d0 s5 H' n- l
to setup-patches6 g9 B* `- I3 L9 T. \* G. t6 w
;; initialize the patch-owned variables and color the patches to a base-color/ z7 n0 a# L$ J6 m$ g8 h g6 T
ask patches
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set intersection? false
?' ?/ V$ L& t# @, e$ u2 r2 g+ a set auto? false4 h; R9 V9 j4 r1 \' I
set green-light-up? true
: V7 h" L: g, g. b set my-row -1
+ F* Y5 ?0 N* n4 H% W1 G set my-column -11 V" z5 e/ `" ]2 W
set my-phase -1
3 d, a1 z( _$ b% k: N# H set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
. _" K0 Y8 L' J7 o7 ` set roads patches with
( Y! `9 ?5 c3 d- v- T/ [$ M# e [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 p u+ ]9 F! p" A! s' D (floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 b1 M; T/ s) G$ u% f
set intersections roads with
4 W4 z# g1 l+ J/ I) y+ [ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and% ?+ s/ h2 h& T) D, r2 A
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]! e4 E; ]% E# B$ }& W9 k7 @
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ask roads [ set pcolor white ]
& q, y ?5 g# m7 ^# k% ~ 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?# o( y+ _' A6 u1 N% Q/ ?9 f/ `
set roads patches with
& f+ j3 O, u: P [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or; m' K/ ]/ f; j$ C& `) Q( ~
(floor((pycor + max-pycor) mod grid-y-inc) = 0)], P2 h7 G, S3 f- 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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