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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。' ]4 C5 X% J; E4 X- {
netlogo自带的social science--traffic grid这一例子当中,5 u$ Y9 R8 P# [- M1 i
globals) I1 Z5 ^! G7 x6 `
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( b0 t! p' Y' R grid-x-inc ;; the amount of patches in between two roads in the x direction
* W o6 }" L" `: z/ u grid-y-inc ;; the amount of patches in between two roads in the y direction
+ j7 Q* q0 J( w7 ]4 W acceleration ;; the constant that controls how much a car speeds up or slows down by if7 w6 Z( \. l" d% [6 e/ w% ~; J
;; it is to accelerate or decelerate
" u4 S9 O" H7 P5 a: \9 G; W phase ;; keeps track of the phase
: T2 r% p. O/ B; C" x/ g' G) p \ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure# c! Z6 Y4 S# k7 p4 s
current-light ;; the currently selected light
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;; patch agentsets7 v! ~3 i4 ~& w+ b+ o* {
intersections ;; agentset containing the patches that are intersections
- I+ l1 N* e: ]$ ^ roads ;; agentset containing the patches that are roads. v2 h: F: r4 Y
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turtles-own
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speed ;; the speed of the turtle1 X) [, X, ^* q1 U6 ^4 Q: R
up-car? ;; true if the turtle moves downwards and false if it moves to the right' U! B4 Z: n2 j4 a" R' F4 u/ F
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( N! ` a+ G, C' X" l0 _2 l5 O
green-light-up? ;; true if the green light is above the intersection. otherwise, false.# [! w1 D! i1 B7 ^
;; false for a non-intersection patches.- F7 a G4 o/ e1 v0 k
my-row ;; the row of the intersection counting from the upper left corner of the& U, Q" j& ^6 s1 E0 n& Q( L7 P
;; world. -1 for non-intersection patches.
, O. |8 G \. f6 m+ z9 R my-column ;; the column of the intersection counting from the upper left corner of the
% R* ~% H# s) A) ]. L" M; s ;; world. -1 for non-intersection patches.
1 J! f! I. {& e- A! P- {0 S. s1 x my-phase ;; the phase for the intersection. -1 for non-intersection patches.) y: t7 J9 f0 i+ \! [ i. |# U
auto? ;; whether or not this intersection will switch automatically.
% M3 d3 V& _& h0 {; R ;; false for non-intersection patches.4 z6 V+ t0 X6 a) d
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;;;;;;;;;;;;;;;;;;;;;;7 r$ L8 a, J. s/ C& Y8 I( p* T# o
;; Setup Procedures ;;% @) s' }2 }1 L. B9 m( A @5 w
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
2 e) A% k. f- n" L M+ N8 w% F;; Create num-cars of turtles if there are enough road patches for one turtle to' B* O+ Q& b7 k) I. c/ }7 O
;; be created per road patch. Set up the plots.* U8 f6 R- T2 J1 M& g1 E* m3 ]
to setup6 T, D: P) `/ B5 Q, a9 L# T
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setup-globals! Z- k9 {% u$ z3 U, ], [
4 K% |% A8 w7 \ w+ [# O/ C4 w ;; First we ask the patches to draw themselves and set up a few variables
' z* U/ q# ]6 ]+ y+ U setup-patches6 O" L3 e. |7 d `9 q4 i
make-current one-of intersections" s4 P9 k0 N+ w$ c y6 S6 }
label-current; R% P/ m6 j9 w3 y3 N
; i( o# W0 `7 H1 J/ I, X set-default-shape turtles "car"# _ }8 I3 f1 x; K
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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 "
5 m* m, B( ^* P2 w "road. Either increase the amount of roads ", J8 ^" K, ~, M" J! G z1 [* P
"by increasing the GRID-SIZE-X or "
! g0 q4 D: m7 Q "GRID-SIZE-Y sliders, or decrease the "% ^' K2 w' O) L, Z
"number of cars by lowering the NUMBER slider.\n"' _6 ~( F3 ^# `6 h5 o4 l7 M* g7 q
"The setup has stopped."). L5 r, v3 J" m+ k! ~! q9 ?
stop
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9 U6 N, L3 g4 I. ] ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color |! Q9 g; u: G0 s- b
crt num-cars# {9 s3 [- e* g7 ^1 B4 V( O% s
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setup-cars8 W% @$ O* J9 h( G. D7 _ R! R4 x
set-car-color
0 r* |3 H. M7 @% e record-data
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/ `- o/ I" V h& H ;; give the turtles an initial speed$ U& Y4 w, A6 T4 O3 v1 k! e
ask turtles [ set-car-speed ]
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2 ~# C( Y- G' O* n1 B+ D. R" } reset-ticks3 h+ h0 ^$ _1 Z+ h5 G
end5 p3 v) g* w: w* K2 b
9 \+ d$ S) U/ Z/ b( Z+ w;; Initialize the global variables to appropriate values
6 B0 } n7 I2 Wto setup-globals
K. ?8 i8 |3 X* Y3 W+ E0 D/ W. b set current-light nobody ;; just for now, since there are no lights yet
* h v# i# S9 Z; V set phase 0
: Y% o2 e( [7 ?/ p+ F2 `5 a4 b# ~ set num-cars-stopped 0" A$ U4 K4 N2 q7 {% _+ }6 K
set grid-x-inc world-width / grid-size-x
% z- W% s; S5 ? set grid-y-inc world-height / grid-size-y+ y+ O' E% O' ^, ^ d0 z0 q' F7 J6 O
) n, Q0 i! {- }# Z ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary- [1 @1 \- Y' \& ^8 b$ k. D/ A- h
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,& M9 y# ~: H# w& ^
;; and initialize the traffic lights to one setting
4 `0 @; q* E) A2 B. _to setup-patches
, U' ~8 C) x# i9 z q! g# \, X3 o ;; initialize the patch-owned variables and color the patches to a base-color
; q$ y4 u0 \) Y3 \ ask patches$ M9 Q( Y6 \9 o6 q
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1 h9 G- C# B: F& j9 g$ U; j set intersection? false
* ?! Q* I8 m- E) r% Y+ W set auto? false
* D8 ~2 L% K( } ~# t set green-light-up? true G/ a9 J2 ]: P
set my-row -1* y& V) |' U9 ^7 e4 ]: e! K7 `* H( l
set my-column -12 r$ a0 K, s6 U+ m4 [9 D3 z* ]
set my-phase -1
& A5 V" j2 ~5 r1 `5 h! b2 } set pcolor brown + 3
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- B* ^6 X% t7 i' t6 Q8 V ;; initialize the global variables that hold patch agentsets- V# H% I% w+ y& W
set roads patches with
C8 Q3 x1 e. E! P8 S# G* U; ^ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
2 ^7 Y5 Z: k6 o/ A3 s (floor((pycor + max-pycor) mod grid-y-inc) = 0)]! s, ~7 M7 f2 T0 H: F
set intersections roads with
, E- u& _# }' [ x: O& J* p [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
; g9 B* w. I# }& g" u! u (floor((pycor + max-pycor) mod grid-y-inc) = 0)]. `3 l* q5 u; ~
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ask roads [ set pcolor white ]
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end
6 j5 t" c0 ]* p% t: ?( a其中定义道路的句子,如下所示,是什么意思啊? {8 J# l8 H8 N. _6 Q) }
set roads patches with+ ]. h* N k2 R$ a
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
) @8 J2 g3 F6 H* A' h' q2 d* i% s (floor((pycor + max-pycor) mod grid-y-inc) = 0)], R$ U, S1 a* 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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