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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。
2 L( b7 }$ P" ynetlogo自带的social science--traffic grid这一例子当中,( G. ?& h! u1 L
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction# H1 d% `/ ~! f
grid-y-inc ;; the amount of patches in between two roads in the y direction' m, J& {- T2 j; j2 J3 J' S
acceleration ;; the constant that controls how much a car speeds up or slows down by if
9 E" t* g# J1 I' ` ;; it is to accelerate or decelerate
9 m# ~. e: Q- O' T: y# t phase ;; keeps track of the phase
+ n' }: T# T9 }! u: l# r" @ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
6 y6 [/ o1 i8 g: h- Q9 G current-light ;; the currently selected light
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;; patch agentsets5 f7 Q: H ?. x4 O/ ^& ~" x" g6 v
intersections ;; agentset containing the patches that are intersections, o( R+ X {) C
roads ;; agentset containing the patches that are roads
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! J) J9 L# r. W# x$ b5 {0 qturtles-own
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5 g$ ~+ L: O% c speed ;; the speed of the turtle
" u+ ^. B9 z# A e9 B$ F up-car? ;; true if the turtle moves downwards and false if it moves to the right
8 @: U* ]9 w: @5 S1 h+ J wait-time ;; the amount of time since the last time a turtle has moved
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patches-own! h7 } g+ c T% ]1 k
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intersection? ;; true if the patch is at the intersection of two roads
; I* U9 {. ~; ~( ?8 z) H) P9 ^ green-light-up? ;; true if the green light is above the intersection. otherwise, false.2 y$ q! \! F/ E" C% f
;; false for a non-intersection patches.
, T& M- [6 W5 y' n) B1 d0 m2 J my-row ;; the row of the intersection counting from the upper left corner of the0 C# Z6 I- K' J. i' q
;; world. -1 for non-intersection patches.
6 b' S7 M. `# P0 e my-column ;; the column of the intersection counting from the upper left corner of the
1 r6 F8 Z s% y" r- P ;; world. -1 for non-intersection patches.
- D7 t0 `# x' M( l% B$ b my-phase ;; the phase for the intersection. -1 for non-intersection patches.; [: I# K7 ~3 R) X. t* w3 \9 V9 Y) r5 c
auto? ;; whether or not this intersection will switch automatically.
8 G) s: U' B( ]/ u- I; a! @ ;; false for non-intersection patches.( }6 L3 ^( r$ E4 K i1 N* y
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" D& {8 l0 c' Z+ v& T4 s$ ^ Z; h;;;;;;;;;;;;;;;;;;;;;;, G6 \! Z% m, E0 {% O- ]
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
2 S# S" e( }8 _" @! l) I& V% _;; Create num-cars of turtles if there are enough road patches for one turtle to
$ i* m# Z' ]8 A9 u8 `8 a7 U$ M# c! |;; be created per road patch. Set up the plots.: J+ `% |6 I4 q. k8 V
to setup
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* ^7 y8 G- o. D) q( p7 u, h setup-globals
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;; First we ask the patches to draw themselves and set up a few variables9 E" P+ }/ C. @# F0 M+ s+ k# I
setup-patches9 F! u: K2 e, T; {
make-current one-of intersections; m7 e* F+ K# h# e8 H9 {
label-current
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, y+ k' ^, Q" A( G; D7 O& d set-default-shape turtles "car"
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% d4 T8 P( i1 d4 G; U; V/ b if (num-cars > count roads) t* p$ q/ P* P0 y" X, Y5 Z+ h3 a
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user-message (word "There are too many cars for the amount of " G2 U# [ L6 U0 Y
"road. Either increase the amount of roads "
- \- Y) y3 \( b& G+ y "by increasing the GRID-SIZE-X or "
: w8 `, m8 S3 ?' K3 J9 R) x2 N; M: ^ "GRID-SIZE-Y sliders, or decrease the "
5 U8 P' D6 N8 `* c( z4 \+ u "number of cars by lowering the NUMBER slider.\n"
2 s( I. j( P J: a) y+ } "The setup has stopped.")8 s$ {2 {2 g* R: Z' A }2 K
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
; [8 e7 Z5 y8 p: W# U crt num-cars
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setup-cars$ B0 M4 S* l: a' h* @# `) B
set-car-color' I9 O& W8 @. ^
record-data
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;; give the turtles an initial speed: G* K+ ^5 c- r6 p
ask turtles [ set-car-speed ]
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reset-ticks0 \0 n) ?; r4 P; H' g$ q
end
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1 T! W, I* f4 m% x. R;; Initialize the global variables to appropriate values: P t3 y9 g/ Q2 [& R
to setup-globals" E/ v' G' `0 x% R. {. i
set current-light nobody ;; just for now, since there are no lights yet
8 P6 G9 E( P. y: h1 q; X set phase 0
9 N* Y0 o9 F/ a& i: } set num-cars-stopped 0
@' g- i4 p! ~$ `; A! Z set grid-x-inc world-width / grid-size-x) s. H; Z( \) b' ^, n! J5 L
set grid-y-inc world-height / grid-size-y& q4 @: |) V% Y0 V5 ?0 S R! s
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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/ g7 s/ O6 a: v+ T+ A* H2 w set acceleration 0.0990 K$ k/ j5 Z( s, U
end
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6 r w. h6 s4 k1 f2 N& o;; Make the patches have appropriate colors, set up the roads and intersections agentsets,4 _: p1 J5 P6 R
;; and initialize the traffic lights to one setting
- p) ?9 |5 |/ Y& h1 rto setup-patches
, g6 ^+ U3 H% A/ M: _/ q3 K: F9 ^ ;; initialize the patch-owned variables and color the patches to a base-color
7 k0 R# Y9 G0 U0 g2 _+ b* [ ask patches O" J' r0 f8 H) v6 g
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set intersection? false
/ o4 V, w! W" a: ] K* M. ~0 \ set auto? false; {" Z' i4 T( ?3 o
set green-light-up? true
0 I$ W% l% }0 H4 K; G set my-row -1
; p# Q2 k V4 |$ r' j set my-column -1$ |7 h* g4 b, V" H
set my-phase -18 x- _' d+ F/ z
set pcolor brown + 3
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8 w9 |6 Y2 l- u: z& i ;; initialize the global variables that hold patch agentsets0 H9 \/ A3 C. g( H6 ]0 h
set roads patches with" ?/ I# S. b5 k$ }2 j" W: w/ {/ h
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' p% l' [2 O3 F" o6 T
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 W$ U( N9 b1 S9 x$ |& ` set intersections roads with& s- j( G* \: K. d; G, s6 s
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and% Y' Y/ Y) }6 j& e6 V4 U
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]: Q+ u4 W& Z2 n& A1 I
5 `3 x! }; R& P9 e) | ask roads [ set pcolor white ]
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" p' A- B+ B0 O0 Bend
+ f, w0 X) o' ~, c其中定义道路的句子,如下所示,是什么意思啊?
4 Z8 C* d4 w/ _ set roads patches with9 P' \' l7 h8 a3 {
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or& L8 N9 r9 f+ y9 j/ P! ]
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) b: E; \: r! N) l! l$ V! i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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