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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。' s+ O9 o) o9 l8 b6 h, ]
netlogo自带的social science--traffic grid这一例子当中,
% V# e& N3 x. ^' F) h7 bglobals
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; l* [" I& P$ h) ^' t% M grid-x-inc ;; the amount of patches in between two roads in the x direction
1 t, q: N! F9 a+ c% v grid-y-inc ;; the amount of patches in between two roads in the y direction
4 u/ O4 r9 k2 H" A2 E# J2 m acceleration ;; the constant that controls how much a car speeds up or slows down by if
2 u. k: \6 S, y+ A ;; it is to accelerate or decelerate
) M+ ^9 {% N6 \) ]5 T phase ;; keeps track of the phase4 y7 H$ d2 g1 W: M& B* `+ S3 f9 _
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
5 _7 \. M/ N$ K* M6 y, e' R" d current-light ;; the currently selected light
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;; patch agentsets
* W) _. T8 P N8 W) a. d8 {0 o7 m* l intersections ;; agentset containing the patches that are intersections
( }7 g1 Y3 K6 [2 K- R$ s1 }' q roads ;; agentset containing the patches that are roads% _/ K: `: ?9 K1 [" Z( F8 M
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turtles-own) ?( m5 W5 j* F" [5 \- ]: N: X2 |
[
: E# I3 K& T8 M' {, m* t" L speed ;; the speed of the turtle4 F N0 Q3 T/ F& W2 N
up-car? ;; true if the turtle moves downwards and false if it moves to the right
7 g- @* v* o6 [6 R" r+ c wait-time ;; the amount of time since the last time a turtle has moved
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0 k2 q) p, F% J8 Hpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
4 X: h3 c* D6 [2 g% i green-light-up? ;; true if the green light is above the intersection. otherwise, false.6 e' @- @6 K1 }' z/ P- G K
;; false for a non-intersection patches.
# }7 l4 {8 n' w$ c2 Z4 v my-row ;; the row of the intersection counting from the upper left corner of the+ {, e. x6 D' k
;; world. -1 for non-intersection patches.
' ^) J& C$ Y+ R: \ my-column ;; the column of the intersection counting from the upper left corner of the% W; n' r9 x8 e3 |! G9 b
;; world. -1 for non-intersection patches.
' F1 o/ r8 b8 f' @5 A" } my-phase ;; the phase for the intersection. -1 for non-intersection patches.
2 m" u& ?; y$ j; b, E& _$ R auto? ;; whether or not this intersection will switch automatically.
# X, |" k8 z$ [1 {. }. i- Q6 i ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
9 |1 u. h$ A# X, D- A, s;; Setup Procedures ;;+ b# P, k: I+ W0 h! l0 s# }
;;;;;;;;;;;;;;;;;;;;;;' A8 ]& A% C# J* ~' f6 u: {
- D0 W1 A5 z7 H. O" T;; Initialize the display by giving the global and patch variables initial values.
# I n+ i% D' E; o# H( Q;; Create num-cars of turtles if there are enough road patches for one turtle to8 j" x5 X6 C$ S
;; be created per road patch. Set up the plots.
; W0 V. l: d1 Q9 f! K6 Nto setup
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
' z: x- K+ ^4 g% @7 X setup-patches
O0 o2 a. R7 ` make-current one-of intersections
, j# k* e2 {: E( T; G) L label-current
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: \: [, F+ K l$ Z set-default-shape turtles "car". g$ Z9 T Q, B8 W9 ]
, M$ m7 Q2 K/ ~* h3 b$ L# ^' i if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "$ n$ l8 ~& A* ], C
"road. Either increase the amount of roads "% R5 n9 C: d$ l0 h9 E' o; W q
"by increasing the GRID-SIZE-X or "( w( V2 i) W/ A& C n/ s3 P
"GRID-SIZE-Y sliders, or decrease the "6 A( O* w9 P8 A s& [0 L7 [
"number of cars by lowering the NUMBER slider.\n"
6 ~5 Z. `( v3 B$ u0 P "The setup has stopped.")) V- w& `: E8 M: R* A
stop1 D. y2 r6 {- a% e7 u" l
]
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( L1 {0 Y3 N/ O6 O, m ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color* g+ w$ j1 R. \) c
crt num-cars: U+ k# Y' f9 A5 H5 ]7 q
[
& J m0 B1 R( ~3 J setup-cars( j1 Y( q+ \+ F5 g* G
set-car-color: p& \6 U0 N" l: D( U$ X
record-data! z8 S( i+ i7 y9 y7 c
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" C; x- O7 `& P$ P$ D+ j- { ;; give the turtles an initial speed
- U2 `3 n/ m" E3 }( O ask turtles [ set-car-speed ]3 ^& I( x/ E5 K+ l6 s( i
# u4 s, ]7 q, E reset-ticks8 ?" }0 K6 y. N! w- D* |
end
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;; Initialize the global variables to appropriate values- i" U) `% [# _6 l. L
to setup-globals! d2 w- g4 Y% K' U$ S4 _7 G) p
set current-light nobody ;; just for now, since there are no lights yet6 W j" R" n8 ?0 F- D: W. y) g
set phase 0 \/ ~; s1 T- B) T
set num-cars-stopped 05 x1 y( M9 Y! q5 l
set grid-x-inc world-width / grid-size-x7 @/ w: V% }, P. @
set grid-y-inc world-height / grid-size-y. i! Z% N* ^: a5 ^( x) }( U
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
$ M: z- ]7 P" K set acceleration 0.099
3 [7 Q3 F" r6 F9 [' y8 u- bend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
: y. r l( M6 M;; and initialize the traffic lights to one setting) t1 R6 ^# t/ U, d
to setup-patches
, i; M% P/ h# |( O/ K4 }& u. Y: a ;; initialize the patch-owned variables and color the patches to a base-color
2 i5 W, w( e/ h* K( d ask patches
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5 a8 {3 o6 z4 X. u set intersection? false
) d0 x4 x- F, c0 B( W set auto? false
0 J% C2 | g! A0 a( ~& J# f" O1 g set green-light-up? true. x# h9 \' [) ]* k
set my-row -1# F& m: P6 [: p( \3 _. u
set my-column -1" `. @: h! W7 V0 s* X4 C, a
set my-phase -16 U. m) K2 p2 v! W5 @' l
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
4 T& _' C/ b7 y! c set roads patches with
$ A: p) e' t8 Z B3 o. Q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
) f, y1 p! t0 r% n (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 Q7 g" P: j0 M set intersections roads with
4 z$ ~7 w' k3 P* H) a [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
: ^- Z/ e+ P, @! r (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]8 }( a+ j! S4 Z5 h1 _
setup-intersections
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) F: g R# Q4 b% Q( g( W2 K其中定义道路的句子,如下所示,是什么意思啊?
2 x) O4 O3 b9 s" I set roads patches with
2 L4 v% E( n+ [- F: n; R [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
4 ?+ a4 l) p; E. u (floor((pycor + max-pycor) mod grid-y-inc) = 0)]% i- q( o; ?! g
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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