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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。
; R1 J' }9 O- D1 x# m Onetlogo自带的social science--traffic grid这一例子当中,
2 C U0 M6 J6 gglobals0 f. y% x% U7 Q2 G& Q/ T i
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grid-x-inc ;; the amount of patches in between two roads in the x direction; N& v1 }, |& s) r/ W. v
grid-y-inc ;; the amount of patches in between two roads in the y direction
0 K6 A: l3 i( M$ E+ E/ M2 d1 \$ ~ N acceleration ;; the constant that controls how much a car speeds up or slows down by if0 M" v. E% D R' g0 J" t! y
;; it is to accelerate or decelerate; S( N( ] e2 c u! \+ M
phase ;; keeps track of the phase
% G5 w( z2 p1 g2 K# q, u num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
, S/ k+ i. c* ?) ~ current-light ;; the currently selected light
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$ i; L. M1 n A9 c- ^. E ;; patch agentsets
2 t [1 w+ ^1 s intersections ;; agentset containing the patches that are intersections! g0 }7 \: s( f: p
roads ;; agentset containing the patches that are roads3 i$ E( a' j" F5 x+ ~
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turtles-own
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speed ;; the speed of the turtle K/ q( M3 W: [8 a( {4 q& L
up-car? ;; true if the turtle moves downwards and false if it moves to the right
( |% E9 M3 @1 ~ wait-time ;; the amount of time since the last time a turtle has moved
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7 T/ v0 B* i) A4 i6 K) ]patches-own3 u1 V# A) @$ i# `8 a# A" F; j
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intersection? ;; true if the patch is at the intersection of two roads) P# C$ k* F4 g1 L+ X
green-light-up? ;; true if the green light is above the intersection. otherwise, false.1 S6 ~, X7 H7 K. l6 R6 i# g7 A( @" K
;; false for a non-intersection patches.% m/ _ I3 K, n& [
my-row ;; the row of the intersection counting from the upper left corner of the
: q0 s4 W; T% V6 D ;; world. -1 for non-intersection patches.4 w' u& {4 @( a1 I
my-column ;; the column of the intersection counting from the upper left corner of the
! x. Y' f! s" x4 D9 z ;; world. -1 for non-intersection patches.
- Z5 J2 G+ G% w) x1 O S& Z my-phase ;; the phase for the intersection. -1 for non-intersection patches.# N( ~7 k8 b. r. N0 D9 X1 g: y
auto? ;; whether or not this intersection will switch automatically.5 g4 U8 L5 ~3 E/ N6 W0 k
;; false for non-intersection patches.6 N2 U4 ~9 A d/ R: p& i& R; y
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1 L0 u5 w+ C8 u$ Y;;;;;;;;;;;;;;;;;;;;;;7 _, r; L+ j3 r
;; Setup Procedures ;;
5 k+ I" R* u% Z2 V5 P;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
( d! U1 q8 }0 f4 E/ u; N5 G3 A;; Create num-cars of turtles if there are enough road patches for one turtle to7 x" F9 S- A& @0 c. [& z
;; be created per road patch. Set up the plots.
$ d$ V0 A$ }: V8 E1 A/ L' R/ s' E; R! _to setup
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0 W/ C/ q( d' M& Y8 J! H1 W) a setup-globals
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;; First we ask the patches to draw themselves and set up a few variables4 A# v& Y9 j0 b* L) E
setup-patches
3 d9 {" b1 B- {; q/ o: ^ make-current one-of intersections
+ d; x' w8 h# d3 D label-current) S+ F" g. n& K& o" Q9 B o g
0 O$ n; f. z2 ^. t set-default-shape turtles "car"
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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 "1 H3 T! L& N9 M( _. H0 P( A; |3 ?4 z
"road. Either increase the amount of roads "
7 Q4 I# U n3 F8 f "by increasing the GRID-SIZE-X or ". b% n, w% }5 ]* v! P- j
"GRID-SIZE-Y sliders, or decrease the ", C# ^, J; D( K3 t7 m
"number of cars by lowering the NUMBER slider.\n"6 f" t) S9 R T6 E6 p
"The setup has stopped.")8 c* ?0 R: P% d9 ], F0 X
stop7 {8 \% j& e8 o5 C7 ~
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( j/ z0 H3 w" v1 Y0 i ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color! y- v9 S9 I9 _/ h
crt num-cars
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setup-cars% w. Q$ ^8 L9 C# F& A. l% a' R
set-car-color
5 @+ M2 t% a5 L6 K8 C$ {3 A record-data% @, ]) N7 p4 \5 i% A, T/ X
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/ ~; a- H. W2 [2 ? ;; give the turtles an initial speed
" A( S- |1 y5 Q; z5 K- p4 G ask turtles [ set-car-speed ]
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reset-ticks8 C0 q5 L0 T+ D. {
end; B( ^% p0 v% O& O6 a1 X
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;; Initialize the global variables to appropriate values6 \9 q( ]' Z- `4 r
to setup-globals6 `0 O+ w- O* w+ d- Q) M y
set current-light nobody ;; just for now, since there are no lights yet+ s" {0 B1 v1 X' w. r' Q
set phase 0/ F) D) p" u' S5 J. ?( h+ Y
set num-cars-stopped 0
* [! K: ]; T; w set grid-x-inc world-width / grid-size-x& O# ^7 P6 D5 v' m& B7 K% P |
set grid-y-inc world-height / grid-size-y
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) J/ @/ d4 ]. {% F+ F' [ ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary) J/ p) X" D0 L2 z9 h
set acceleration 0.099; C( B6 q/ P5 N; o" H7 q
end k: S% m8 B! c0 B( p
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,9 ^4 H6 P9 @1 o& U+ M. i" S
;; and initialize the traffic lights to one setting8 N+ r) ?$ v9 k' V2 ]
to setup-patches; ~ P8 I4 l' s4 [" |
;; initialize the patch-owned variables and color the patches to a base-color
: F" s# H0 x( C/ m4 z- v/ i/ d ask patches
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. o5 b d+ L2 Q3 J9 [+ p set intersection? false3 U6 Z" }3 M) U8 h. f2 R& O
set auto? false
2 Z4 e4 v" f* P3 B: C6 ]! j set green-light-up? true. y+ q `0 M3 E& B5 F# V* D/ S
set my-row -1
& d+ z$ M7 {# w8 W- F f set my-column -1
( j+ D ]" k' t" `9 m- r4 w set my-phase -12 \# ^2 u/ L. v
set pcolor brown + 3, F" j& s( H0 K' a3 q! d
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; z" d5 p! R# I; z. H1 I- [, J9 X% W1 k ;; initialize the global variables that hold patch agentsets! k( q2 K/ M2 `: b; `# T4 p
set roads patches with
; J; R) R5 K' z* d [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 }5 g, ? K& o q! M4 v1 |
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* N3 Q$ v4 k$ O: d, S set intersections roads with* a/ _' N7 t- D, B
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
& P4 e( A) y1 q2 r (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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" U; G9 p' t9 ?& @2 z# |5 R p ask roads [ set pcolor white ]
! U) ^) Z# {9 Y' S3 D4 S7 ^ setup-intersections
& U2 s5 z+ t. y2 p$ ~( nend
9 x* N' s1 S# w9 Z& B: i: d其中定义道路的句子,如下所示,是什么意思啊?
8 u# j% ^: ~( Q J5 q$ O1 ^6 i set roads patches with2 ^6 L' n7 z$ H+ e' s* d- r4 y% l
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
0 b% l' c2 C3 ?7 ~0 B2 C5 C (floor((pycor + max-pycor) mod grid-y-inc) = 0)]) P% k! `# C4 L4 E a
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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