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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。; u, N+ s) \/ E
netlogo自带的social science--traffic grid这一例子当中,
, N+ F' [* J5 L( p" j4 t: jglobals. s6 M. m+ e+ n% A1 Y/ z' j2 g1 U- G
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grid-x-inc ;; the amount of patches in between two roads in the x direction
C$ m* f' I0 `- U+ R grid-y-inc ;; the amount of patches in between two roads in the y direction
k! |# \) `- |8 Y& ? acceleration ;; the constant that controls how much a car speeds up or slows down by if
! F3 X4 B' \$ J1 }, r1 i ;; it is to accelerate or decelerate
% @* t% d9 ~/ W+ u7 n phase ;; keeps track of the phase( S i Z; ^! C0 ?' u& A
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure: A, |' ]% h7 R @! I$ A5 `
current-light ;; the currently selected light9 k7 X5 t9 p/ h5 E" v3 V/ ?
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;; patch agentsets8 M& t, n% a$ D+ F
intersections ;; agentset containing the patches that are intersections
" F- e. a$ p( `* x7 D! \ roads ;; agentset containing the patches that are roads
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5 B) n) O$ t) u/ ~turtles-own9 E7 L7 g: V" Z( A
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1 d9 Z5 ^: ?7 _% i8 l1 ^ speed ;; the speed of the turtle
! N* E. q- \/ ` A/ [& ]8 C up-car? ;; true if the turtle moves downwards and false if it moves to the right9 |- U. i1 S' t# [6 ^0 _( c
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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# g; u5 r1 G4 a% n- W; ]0 U intersection? ;; true if the patch is at the intersection of two roads
) J8 q, T+ C" y: ` green-light-up? ;; true if the green light is above the intersection. otherwise, false.
+ B3 m/ d6 I+ I/ N \$ ]" z ;; false for a non-intersection patches.+ g/ Q- t% k8 r1 Z4 r2 ]6 ]
my-row ;; the row of the intersection counting from the upper left corner of the
- v- \: x8 t2 N ;; world. -1 for non-intersection patches.
; V% e1 H+ M9 C my-column ;; the column of the intersection counting from the upper left corner of the0 P9 U4 \' o! [1 `3 ~( o& q
;; world. -1 for non-intersection patches.
2 _3 I7 h* E/ \ my-phase ;; the phase for the intersection. -1 for non-intersection patches.
7 I. b$ a8 e! `, I auto? ;; whether or not this intersection will switch automatically.( J0 \* _, T p9 r, X0 h5 D
;; false for non-intersection patches.3 d; o' i; ?7 F" p4 }0 Z
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;;;;;;;;;;;;;;;;;;;;;;" T# v3 h* N0 r% Z: M0 Q
;; Setup Procedures ;;0 Q& x2 A* t$ C4 M+ p K+ r
;;;;;;;;;;;;;;;;;;;;;;
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6 ]! _& R+ j, v4 x* R& M;; Initialize the display by giving the global and patch variables initial values.
% b9 X ~1 L. k' S2 }$ i k0 q;; Create num-cars of turtles if there are enough road patches for one turtle to
$ |; r$ d1 K' X+ o;; be created per road patch. Set up the plots.
) ~- @+ ]8 @# S) m0 e' ?to setup& l) I6 W2 O, k9 O5 X7 J, \; \
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables; h, U, s- l) w) u( R6 j+ h% ]6 C1 H
setup-patches+ H4 V; U" W4 k- E; E/ [
make-current one-of intersections
0 t( J- U& w4 Z' j! n label-current% v0 A2 x( t* h# ` G
, l" K5 q6 q1 H9 {6 Y set-default-shape turtles "car"
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: v3 c( C* {- d9 U2 t, k1 U- T3 S if (num-cars > count roads). _4 ~' q0 U! ]9 ^: M
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user-message (word "There are too many cars for the amount of "8 b5 _+ ?- v8 X' }( S3 a
"road. Either increase the amount of roads "
1 l, e+ Z( @# K/ }8 g0 @ "by increasing the GRID-SIZE-X or "! u) ~8 e+ u) n. ?/ `
"GRID-SIZE-Y sliders, or decrease the "
8 V: b' B& G( K% F( A "number of cars by lowering the NUMBER slider.\n"
* f, N) x- u- u E8 z H2 P "The setup has stopped.")
6 b u5 G& ^" u9 V: B2 Y; S6 |. P stop
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9 V' @: e2 q' t( b3 w, u ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color3 Y. I3 D: H. Z* c% A Q* U2 u
crt num-cars
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setup-cars! D f9 h9 d! d, A7 n6 k
set-car-color7 m! I' q( X7 c
record-data
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$ J/ b. i/ ~6 D ;; give the turtles an initial speed
) ~3 o1 P3 o7 f j ask turtles [ set-car-speed ]4 M5 U! M5 a. k5 W8 ]4 {
P6 v- p0 D3 f' Y) K reset-ticks1 T% c1 z# B% u6 C& Q4 R6 ^
end) h$ s& a Q. ?/ q6 K
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;; Initialize the global variables to appropriate values1 A, u% f; J' a8 m" u5 R
to setup-globals# W2 u1 V7 k$ H: g
set current-light nobody ;; just for now, since there are no lights yet
: K# }6 X% k8 @7 }- J8 x- K set phase 0
7 }: v( n4 s, p2 a4 p set num-cars-stopped 0
$ c. K* j! R8 w set grid-x-inc world-width / grid-size-x8 t' m" N" ^# E2 M
set grid-y-inc world-height / grid-size-y1 Y% z- e0 R) a: m D9 g
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
% J) I0 z8 D& ^9 ?- {. l2 w set acceleration 0.099
4 \$ \1 U6 H* z' A+ fend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
2 T- [* p& R6 G* P1 S9 }# v;; and initialize the traffic lights to one setting1 a7 h1 [" M% F6 P; S9 L! b: r# C
to setup-patches
- @- P# w; [; C+ t" m$ ] ;; initialize the patch-owned variables and color the patches to a base-color1 ]% T7 R$ h: m! s; `2 t
ask patches; S) A1 i! i# \3 }0 b; Z. Z
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X# i q6 \# ~# p0 N set intersection? false; r, z9 X6 m/ q1 X* }
set auto? false0 r% j3 R( I8 F' z
set green-light-up? true' o! I2 @/ t6 O0 j% L
set my-row -1
* _1 Z4 E+ }. }& s/ ^# q3 B set my-column -1
# H7 |; k: N" i3 I, | set my-phase -1
6 B. B( o3 ?* c, ]# Z. p set pcolor brown + 3
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0 |9 N1 t' r7 e ;; initialize the global variables that hold patch agentsets) N8 }6 n8 Q+ V. V/ k9 a, X
set roads patches with1 w9 v- Q4 W2 w
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 J' e. G" Q6 B( l) F (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ k5 w) ?- N+ h/ M% o set intersections roads with
* \! f4 P$ P2 z# o# k, j, p [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and6 _* [' c9 p8 p2 X7 p; f# j3 a
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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& _) \: {! {! A+ s) Uend
3 q. s& \. \' Y0 S& N# M- j/ ^- U其中定义道路的句子,如下所示,是什么意思啊?: ? I. r* L; x! ]2 |. m. ^
set roads patches with
8 h8 t" `2 o( I( c [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
& }; H! r" @9 t- H. [7 e4 u (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
5 O0 R# `9 g0 W3 z- c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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