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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。 g5 V" Q2 d8 r% W; ]. S0 V
netlogo自带的social science--traffic grid这一例子当中,
( e2 r- n1 ~$ D, r9 Tglobals* k1 g6 c1 R+ c6 ]* x: S
[
$ W2 B3 c, W" T% {3 C grid-x-inc ;; the amount of patches in between two roads in the x direction& F8 C9 m4 t# Y. R$ R' E- p
grid-y-inc ;; the amount of patches in between two roads in the y direction
5 D. @9 T, N; _5 s6 }; D acceleration ;; the constant that controls how much a car speeds up or slows down by if
( T/ v- G9 P- \ ;; it is to accelerate or decelerate2 [% ]6 G! i H4 `+ a1 a. Q
phase ;; keeps track of the phase
/ ], L5 h2 l- ^6 L num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure% ?. K+ `! }9 m
current-light ;; the currently selected light" ]! }) W9 ]1 l/ p( S) \
/ C+ e* {0 [* B% s ;; patch agentsets, {0 w* r3 Z% q8 e
intersections ;; agentset containing the patches that are intersections
" m# ]' X6 s' s5 K roads ;; agentset containing the patches that are roads- k$ r; s" i; s; T
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turtles-own
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speed ;; the speed of the turtle) X% g2 r. t( G% b# d
up-car? ;; true if the turtle moves downwards and false if it moves to the right" R( ]# B0 ]7 z
wait-time ;; the amount of time since the last time a turtle has moved2 C0 U9 v* v& k5 J1 e
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* H. t4 z; n5 L- _( q) D* lpatches-own
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/ H k6 ^' Z8 E8 e* J5 s% } intersection? ;; true if the patch is at the intersection of two roads
$ }/ `; b$ L9 ]1 U green-light-up? ;; true if the green light is above the intersection. otherwise, false.
/ D% S! _2 E: [6 B$ C% c0 z ;; false for a non-intersection patches.# j* \+ C0 h, I" D3 O
my-row ;; the row of the intersection counting from the upper left corner of the; T s& Z3 I& Y; [- E$ _
;; world. -1 for non-intersection patches., _- |- R* Q3 p( N1 [: n1 i/ {8 n
my-column ;; the column of the intersection counting from the upper left corner of the8 s$ S% H: Z9 E. [9 G
;; world. -1 for non-intersection patches.
, M q+ r+ H3 P7 p4 \ my-phase ;; the phase for the intersection. -1 for non-intersection patches.+ }9 G) Y0 w! ~
auto? ;; whether or not this intersection will switch automatically.% n1 k9 {! [. ^! i5 G- A) d
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;9 M4 t: R. s2 G" Z9 m3 m) e
;; Setup Procedures ;;
q5 P( p7 [6 r* |6 X& O;;;;;;;;;;;;;;;;;;;;;;- t( D, T3 ^$ ?! y/ w3 `- K
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;; Initialize the display by giving the global and patch variables initial values.
% x2 f1 ` M3 B a6 `+ x;; Create num-cars of turtles if there are enough road patches for one turtle to
# E; W Y% g$ v2 [* v;; be created per road patch. Set up the plots., Y4 @8 C7 [. {& ?) y2 u" X" Z# l
to setup
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setup-globals0 [% |6 a) G- d! K) E% k# ]
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;; First we ask the patches to draw themselves and set up a few variables
3 g3 J& ?6 K2 g7 t) f; H setup-patches5 c. }! ], L X$ ^* j
make-current one-of intersections8 h+ p' u* I7 E0 b8 T: O/ Y
label-current! V+ j3 n# V' G+ X+ U2 ?
- O3 \& ?* s" q! C9 U8 w set-default-shape turtles "car"3 a+ w- i4 Z7 Y* |# n* W, ]& g
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "9 s u! M/ T8 w' ^$ q& J! ] D
"road. Either increase the amount of roads "
9 c+ A) C8 E* f2 T "by increasing the GRID-SIZE-X or "
" C/ Z+ Z# z% n& U; L, U0 A, B "GRID-SIZE-Y sliders, or decrease the "
8 q$ ^" n$ g4 d8 k5 M6 i* D "number of cars by lowering the NUMBER slider.\n"
4 D8 f* q9 y) g( G. q' F4 e "The setup has stopped.")
! Q7 r$ F6 X: l* E3 H" H4 H stop
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- u/ ^, h5 k, [/ L3 l ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color$ C5 A7 j* z5 e! k
crt num-cars8 s9 B5 Q9 F& }5 Z. [ s
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; P6 {& p: M8 V- q setup-cars
0 K( [3 k8 _2 H' X b4 S0 p set-car-color
. q* a) U7 I7 K$ v( l record-data
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;; give the turtles an initial speed
. H7 u+ C" T: a5 T8 i) X* K) | ask turtles [ set-car-speed ]
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- Z+ ]; I/ j0 O* O) ^, { reset-ticks6 I2 v( ~6 {9 Z3 D
end
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;; Initialize the global variables to appropriate values" x" e/ O7 n! R; `6 f
to setup-globals) M5 I( t. Z! C' `) i( s
set current-light nobody ;; just for now, since there are no lights yet
8 Q# W" p: S; g/ t$ q set phase 09 w; j }* b8 F& _, w
set num-cars-stopped 0
2 o: Y3 y$ H3 E6 E set grid-x-inc world-width / grid-size-x
3 q( J6 t) v% ]3 x8 i; d set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary* S% P7 u4 O! n+ E6 [+ [
set acceleration 0.099
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% J ~( _% Q/ o9 V;; Make the patches have appropriate colors, set up the roads and intersections agentsets,, }, F4 }4 J& j# B+ m. M
;; and initialize the traffic lights to one setting
, o- u) p# {5 _$ d9 Y, I. Ito setup-patches S8 \7 T4 V0 S' ~6 X. e5 j& M
;; initialize the patch-owned variables and color the patches to a base-color
) u8 S) `- r# U8 v ask patches+ [+ G- D$ n& O- w
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set intersection? false/ E0 i X$ ?- d, k2 j
set auto? false n1 i+ Q/ C# C% T
set green-light-up? true
4 `1 {& ~# I* g+ \ set my-row -1
. Y) ?9 G3 r/ _, M# x- c set my-column -1" I" }$ X( }7 @
set my-phase -1
, X/ l2 n ` w5 g/ M set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
& e2 b3 y- p) _$ t, d5 ]0 S set roads patches with
3 d- O& h0 T1 ]+ L0 R9 ?- k% [9 }5 S [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" l! h3 H$ A* T; u& Q8 ]# M# Z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 j" q5 V; m/ i) T4 x/ [2 }2 N
set intersections roads with
; x: a1 V1 t8 `: ~# J1 m' H! E [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and' n# H x7 _+ i0 |. r9 Q
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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h% v8 Y4 M. H4 E2 k, a! I ask roads [ set pcolor white ]" h' t: Y* h( v( I
setup-intersections" m1 g: j: i( o* q# O8 ?
end$ M( u/ h( I$ T1 e# h2 D
其中定义道路的句子,如下所示,是什么意思啊?
9 e+ \: D, D P! Q8 Q set roads patches with
# ~+ q2 |0 E) ?; v' l9 |5 r$ O [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or3 J+ }: Q- y! m/ O! H2 s4 [& [# L* Y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 L5 Z4 T: ~" x. O/ e, U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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