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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。
T) _) d3 u6 C7 p) Tnetlogo自带的social science--traffic grid这一例子当中,
' R; e+ [3 U& L. M, qglobals
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5 h+ |9 Y( P/ _ grid-x-inc ;; the amount of patches in between two roads in the x direction
5 I4 Q) e y/ \ grid-y-inc ;; the amount of patches in between two roads in the y direction
P# l1 L @* v" n* P acceleration ;; the constant that controls how much a car speeds up or slows down by if' ]$ Z5 b( a! H3 S) s
;; it is to accelerate or decelerate
6 g1 {+ f6 w% ~. b; l phase ;; keeps track of the phase7 k# w# W7 y) R' v! c
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
4 p4 Y; K/ K$ m; ]. P1 a! K9 l current-light ;; the currently selected light
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;; patch agentsets* O' M$ W7 c& n8 a9 S* I
intersections ;; agentset containing the patches that are intersections
% [+ ~' Z6 i" F$ A roads ;; agentset containing the patches that are roads5 f) I( s; z5 j8 A4 O) l- S
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turtles-own
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: o0 W. o3 n1 d9 B speed ;; the speed of the turtle- v5 w: [& t2 v. d7 n( c1 X r- [* ^
up-car? ;; true if the turtle moves downwards and false if it moves to the right2 n; \* B6 W% j) `4 y7 N
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
8 ?7 t' T- f9 ` E, R* O green-light-up? ;; true if the green light is above the intersection. otherwise, false." r7 q6 v2 E- d. H0 ?4 y" K1 U
;; false for a non-intersection patches.
$ D8 R/ Q8 v5 Z0 P9 @" o% w/ | my-row ;; the row of the intersection counting from the upper left corner of the% \" L& q! o9 t6 S
;; world. -1 for non-intersection patches.
6 R r" g! g) q+ t my-column ;; the column of the intersection counting from the upper left corner of the
2 s2 r* i7 M, T8 Y3 t ;; world. -1 for non-intersection patches.
- S# T( p8 D8 c2 Q* Y; M my-phase ;; the phase for the intersection. -1 for non-intersection patches.& u" A# S6 Y+ ~# u, M
auto? ;; whether or not this intersection will switch automatically.
. T- g: |6 l* k! t* U ;; false for non-intersection patches.6 H3 F$ Z: u# p) o5 D) `. V
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( [0 L$ U' p2 m# u( @;;;;;;;;;;;;;;;;;;;;;;
S' t6 M( a" t9 w! e3 l;; Setup Procedures ;;9 d! g. O- M& d0 |0 G. X
;;;;;;;;;;;;;;;;;;;;;;
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9 A/ |" w/ B: U8 P;; Initialize the display by giving the global and patch variables initial values.
* f0 b+ x7 l2 S2 }* K;; Create num-cars of turtles if there are enough road patches for one turtle to# X: D! R, j8 R7 R4 a4 Y) M
;; be created per road patch. Set up the plots.
! [, N( a5 l4 n/ D3 Tto setup2 d; O k, l% D: b2 c) F
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setup-globals
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0 P& M5 r( C( A B, l5 d: c3 `" D' C ;; First we ask the patches to draw themselves and set up a few variables
7 P' {0 n5 N0 j, K; n: d+ E setup-patches) p/ [! Z- `& J/ F) E! X
make-current one-of intersections
$ t3 F+ }5 h/ q2 ]1 | label-current
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0 v" C4 V4 C, d! Q2 b& L# F set-default-shape turtles "car"
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/ s. }2 V5 A" K* n' ~- w if (num-cars > count roads)6 z+ N+ X; p: Q* Z2 H/ H. K% c: i
[
2 V' o. x# \$ z' p6 [; t user-message (word "There are too many cars for the amount of "
' O! [% f2 p: G: q) ?. ?5 f" c "road. Either increase the amount of roads "1 a" v" u$ V+ ~! c- x* a: H
"by increasing the GRID-SIZE-X or "
& }- ^7 {* A& B! z3 J "GRID-SIZE-Y sliders, or decrease the "
$ B4 z& u) V; C! v+ h7 F "number of cars by lowering the NUMBER slider.\n"' \' T9 H) ]- |6 e! V6 Q0 q) X
"The setup has stopped."): y$ m& ?# Q }% @( J5 u" X
stop! L: K8 Q7 K* J! A0 U9 j
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4 v# _3 ?3 ]& Z) H7 E5 t( B, \ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
r5 [2 G9 p) B3 @9 W crt num-cars
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setup-cars
* g1 R p2 e6 S! Y3 f set-car-color
5 x' [ _, m6 u0 f$ d. w+ R record-data
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. ~. E: n4 }( ~8 |1 j T, o3 b ;; give the turtles an initial speed- ^' P& A: e+ @% n
ask turtles [ set-car-speed ]
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+ p# H+ m; ]' m X2 s& ? reset-ticks+ p- ]1 S: y) ~0 ?' G
end
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& i7 n) A, _/ g: v4 G7 G ^6 h;; Initialize the global variables to appropriate values( |: T, c4 U4 u2 \" u
to setup-globals" b6 a! C0 D: z. o" f
set current-light nobody ;; just for now, since there are no lights yet7 @ k1 z) g1 z1 @: D4 s3 k
set phase 0% F7 W0 m# W* l7 A6 P* ^
set num-cars-stopped 0$ ], N- |8 R2 `0 h
set grid-x-inc world-width / grid-size-x& `% @) n& n9 k( d5 [- `1 s
set grid-y-inc world-height / grid-size-y
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) u `7 E. ]) M2 h ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
5 e2 d; @" ~- u7 r# V, W' S set acceleration 0.099! D3 k! ]+ \- N+ ~1 ~* |
end6 P) ~4 i; z1 l! R4 a0 \' x+ u: v
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,3 X, j$ f' U8 _+ J, n9 y
;; and initialize the traffic lights to one setting
. M/ M" L: k! A+ |$ lto setup-patches# Q; P/ L8 O+ |2 p
;; initialize the patch-owned variables and color the patches to a base-color
! t, M# x6 D+ q c& r- M( U* s ask patches7 {$ [- v7 Z9 o- S# ], F
[
1 `7 z! w' S) m. ?4 U# V set intersection? false8 q' e/ h' ^+ P5 \$ P9 o7 G- h
set auto? false
0 k7 e/ P. G+ E" ` O set green-light-up? true
2 e5 i+ V: W0 e. a$ [ set my-row -1
3 P4 I- L8 I# c! d9 z set my-column -1 k+ q. h7 O4 u' u- m1 l1 t
set my-phase -1
& T G/ H% W1 `9 D& b set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
2 Z1 }9 \) b% R' y set roads patches with
$ ~, U, K4 s) y7 z, D- b [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or- E8 B' ~$ J/ |6 ]5 D; T# S
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ P1 N0 ]1 q( N( V" H
set intersections roads with
; q$ K8 Z( g0 i2 a; H* L+ X: ~ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and4 _& Z! j& Z4 E, X) ^
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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其中定义道路的句子,如下所示,是什么意思啊?5 `0 s1 ?/ b G# ]' X' R
set roads patches with1 `/ d" t9 P0 e
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or+ y8 P0 E4 `; J% o7 E) m5 K
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]" q5 x/ ?9 P9 p9 U' q
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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