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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。8 ~ h# a+ w- x/ I
netlogo自带的social science--traffic grid这一例子当中,: y% Z: J/ P) ] A% F( n) F
globals, n/ L. R( h' R; z
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7 w3 T* h+ g: a# A% v* P grid-x-inc ;; the amount of patches in between two roads in the x direction h; K: V; C; Z- s4 d1 K- ]
grid-y-inc ;; the amount of patches in between two roads in the y direction
" @: }" A q1 [% @/ X2 q v5 \ acceleration ;; the constant that controls how much a car speeds up or slows down by if3 Z9 g# J* O& x2 `
;; it is to accelerate or decelerate
% U! Y$ j$ {2 x1 L0 U# n phase ;; keeps track of the phase, Z( v6 F, F* Y
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
. _& R/ ?# ]7 M' J4 q current-light ;; the currently selected light
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;; patch agentsets
- r: ` ^0 [' t1 } E0 K ` intersections ;; agentset containing the patches that are intersections
5 x# m0 ?, J1 B- D9 m4 C roads ;; agentset containing the patches that are roads D/ h( {4 {0 U- B% k
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turtles-own
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speed ;; the speed of the turtle: B7 l K: B3 `
up-car? ;; true if the turtle moves downwards and false if it moves to the right% O8 j4 C5 c+ m- C2 h9 i
wait-time ;; the amount of time since the last time a turtle has moved% G2 T& |8 E! F/ S4 {
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3 f& T9 d: C8 ^% j2 v- `. ^, bpatches-own
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9 k( X2 J. R2 _! L( d ], E intersection? ;; true if the patch is at the intersection of two roads
_- J, {$ r# |! h green-light-up? ;; true if the green light is above the intersection. otherwise, false." p" J, M$ ^7 s H# h
;; false for a non-intersection patches.
U1 w* ?; W! f; H5 [! C my-row ;; the row of the intersection counting from the upper left corner of the: b, C$ {9 n7 V" R% A+ x
;; world. -1 for non-intersection patches.
" u: F, Y& Y7 E4 `* I. K) s my-column ;; the column of the intersection counting from the upper left corner of the
6 v8 g7 W- W- q ;; world. -1 for non-intersection patches.
+ U @- O* }2 t3 z7 A$ p: M/ X! j my-phase ;; the phase for the intersection. -1 for non-intersection patches.
7 e" u4 Y q! L' b- j auto? ;; whether or not this intersection will switch automatically.+ `8 t7 ] r5 D' A! [8 X6 k% e# j
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;. ^1 G' ^/ c$ N8 y% i( B7 |
;; Setup Procedures ;;/ T$ J' ]8 w7 u2 T4 m: B5 r: K9 h+ b
;;;;;;;;;;;;;;;;;;;;;;' y( e! o+ C& @) j) f1 ?+ v
1 d, }: J# X1 O4 P0 V, }/ Q;; Initialize the display by giving the global and patch variables initial values.2 x3 s: u" E+ E& y9 e( b9 E5 J7 t
;; Create num-cars of turtles if there are enough road patches for one turtle to
+ q, I- M4 d& b& ^# J;; be created per road patch. Set up the plots.
3 u2 m+ v. j _' K& e# Jto setup+ N$ p7 x. D6 k/ {# p& E& Y6 ~
ca
) K7 f1 |$ j2 r! J( b" C setup-globals6 b3 K( I- V+ X5 T) @
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;; First we ask the patches to draw themselves and set up a few variables
* v* D, S7 r( v2 [( Q setup-patches
H& Z% O9 ^ V# p8 N make-current one-of intersections
: Q! b; B, ]3 i4 [0 h label-current$ N$ t* ~8 s. U* l+ @) ?
, `* z9 Y/ e5 B) r7 ]( V set-default-shape turtles "car"
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! k2 ~. S/ \# O- s$ a/ f# x, x if (num-cars > count roads)
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6 e3 `% A# B$ s' v/ k; Y user-message (word "There are too many cars for the amount of ". D t6 O5 M T
"road. Either increase the amount of roads "
$ {7 m2 D$ Z/ } "by increasing the GRID-SIZE-X or "4 |7 h0 K: G4 C# w2 f
"GRID-SIZE-Y sliders, or decrease the "
, K" C5 W& T8 Q: P "number of cars by lowering the NUMBER slider.\n"
) ?/ e" f$ t2 i* L0 u' ~% \) R "The setup has stopped.")
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
/ U& E6 T- m4 W. @) } crt num-cars/ b5 }- O- v. g, S
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; p& [9 [" B2 N" b6 z" v setup-cars5 _1 p# H9 p' s I
set-car-color, A. G( t8 g) q0 n9 k, g4 M: I+ r
record-data9 u% t5 c/ }9 ?2 n: A" J/ B8 b
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;; give the turtles an initial speed
" P2 y" d9 E! L2 P5 o& J% {1 V ask turtles [ set-car-speed ]
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reset-ticks7 A' M& o! s. c1 Y
end) _* M; M6 Z' n* S# e4 R3 h |3 E
x. n" _8 T. W0 {;; Initialize the global variables to appropriate values
$ b H5 i7 D3 ^) S5 q8 e+ r* tto setup-globals
4 j9 B% ^$ n* a8 q9 d) A; m; a set current-light nobody ;; just for now, since there are no lights yet1 Y' G# N4 K' R H2 |3 p
set phase 0/ W: K9 K8 e% q, j" P; ? ]( [' e
set num-cars-stopped 0
8 u2 }9 j, s0 X) X" b0 M set grid-x-inc world-width / grid-size-x
4 M! a4 c% j2 t% _ set grid-y-inc world-height / grid-size-y
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- h( p! G1 R0 ? ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
: N+ z! ]4 j4 G$ F/ m" l+ a$ Z5 S set acceleration 0.099; j, n5 W# R2 z
end& r: @. l* X* y) x
" G `: b3 M& ]9 E1 _;; Make the patches have appropriate colors, set up the roads and intersections agentsets,0 n& ^7 b9 b; s( e ^
;; and initialize the traffic lights to one setting6 j6 o7 d' u3 n q
to setup-patches ], b: Z l9 L2 g( C
;; initialize the patch-owned variables and color the patches to a base-color
5 } L* r; J" z5 e4 N ask patches9 x/ y5 h) b- F9 s& b
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+ c! a0 E$ g6 J/ P set intersection? false
P& G6 V- X8 @- @( L. T$ E( } set auto? false
( D9 b) f3 z! L, T. S6 t& ] set green-light-up? true
; E0 ]6 j) J/ R; o set my-row -1& W3 W; z% D6 U, g0 g5 `
set my-column -1
1 x6 E; s; Y6 A. R set my-phase -1
4 C9 U: {4 T7 K m/ ~' Y/ { m6 _ set pcolor brown + 3
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; x1 z. b* n/ R) K# h. w ;; initialize the global variables that hold patch agentsets
4 A+ V! E7 X, U set roads patches with- h1 F* |4 ]& k5 w2 `2 F, l
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ E1 `3 [( H/ ~% t2 g) d5 j (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
' f9 C+ I% {: f3 D( W set intersections roads with6 E( G! o K% F, `9 z" o$ n% @6 v
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and! U) x. d; Z% |# W+ G
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]! ^+ b0 P; t* O0 R* j- `- m
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?
5 Y7 |" ?5 ^; ^2 K set roads patches with2 O+ C- p6 [ U$ ^0 G: y2 u
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or: d6 Q" ~5 e* Y: v% g3 R# D
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
+ W( G9 ]" l2 W3 f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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