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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。, p+ v/ L; m- m. m* c' @1 p3 e8 W
netlogo自带的social science--traffic grid这一例子当中,* g/ B' q5 j5 w& h! S% A9 i
globals
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) a) ~4 n+ g# ^2 {' r* f grid-x-inc ;; the amount of patches in between two roads in the x direction
1 S. R# }6 N ^# s" N. N grid-y-inc ;; the amount of patches in between two roads in the y direction
: E0 T; |' A' s- | acceleration ;; the constant that controls how much a car speeds up or slows down by if
: _9 r7 c/ u; d( J. G ;; it is to accelerate or decelerate
/ }6 ?' @; e; Q# P0 ], \, _. ]( | phase ;; keeps track of the phase" b/ s3 v" X, X; {
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure5 }0 u9 a9 r! U8 @* x* ~, l" l
current-light ;; the currently selected light6 _# C( F5 `) A
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;; patch agentsets$ R+ f7 L1 K3 k% J% O# W2 T
intersections ;; agentset containing the patches that are intersections
5 r6 S3 B" K% x* W$ V6 u2 ]& Q roads ;; agentset containing the patches that are roads6 `' J9 e& N2 [4 A& U& s) [9 ~
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turtles-own
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speed ;; the speed of the turtle
- U b/ J5 f. k3 ^ up-car? ;; true if the turtle moves downwards and false if it moves to the right% {7 U0 Z1 N K9 O
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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a% d/ m# x& P# }* I! S8 B5 q intersection? ;; true if the patch is at the intersection of two roads
. N( N* @& G# j" j" i green-light-up? ;; true if the green light is above the intersection. otherwise, false.
0 L, j/ _' s& g) `. C" V ;; false for a non-intersection patches. }' ]3 B! Z$ ^& I4 w
my-row ;; the row of the intersection counting from the upper left corner of the0 K1 h' _0 d4 n0 M; m
;; world. -1 for non-intersection patches.( E: Z# B, S+ t/ V3 d# p
my-column ;; the column of the intersection counting from the upper left corner of the
1 f2 k1 y2 {+ x6 k; v ;; world. -1 for non-intersection patches.
' @/ Y2 c {" s" Y my-phase ;; the phase for the intersection. -1 for non-intersection patches.4 @$ G4 d/ G1 d
auto? ;; whether or not this intersection will switch automatically.
$ n- w6 ^8 t1 A3 Q ;; false for non-intersection patches.; f! P' f+ t8 N% c. K- X
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! J/ {7 `, B" u) c- M: v;;;;;;;;;;;;;;;;;;;;;;
# B# k- _' B( B# r4 F;; Setup Procedures ;;/ I$ J8 m. j) q8 u. o) f6 S& \% n
;;;;;;;;;;;;;;;;;;;;;;
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; [3 G+ o$ `- j; X6 f1 i5 a0 p;; Initialize the display by giving the global and patch variables initial values.
4 q: P: A; Q! B2 k2 j;; Create num-cars of turtles if there are enough road patches for one turtle to# W' k$ e, A/ F& k" s* z4 u# h
;; be created per road patch. Set up the plots.
! g" Z0 x, a, \5 \, V% M2 a4 Q6 hto setup
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: k/ G$ I3 w8 } B" u& `, K setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
2 J* P( v6 e/ u) T) q setup-patches [0 W% ]' x4 A% a
make-current one-of intersections
. y* h6 e- \. | label-current' [/ c" x1 q. H% k
/ T/ |9 z- c' b+ @- N- | set-default-shape turtles "car"% |& {) w3 n( h0 W, B
4 z1 m3 X: ?* M' L( g if (num-cars > count roads)% H( ?, ?( g2 z' r# _ t5 F# o
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: X, q% K. A7 L& Y$ r$ D( ] user-message (word "There are too many cars for the amount of "4 l9 V; |6 ]$ d% L; l
"road. Either increase the amount of roads "
0 ~4 ^& p$ U9 h- E/ G- l( e "by increasing the GRID-SIZE-X or "0 i4 m! Z4 L9 g
"GRID-SIZE-Y sliders, or decrease the "
$ X3 i! j# x4 M/ @$ X0 t: X "number of cars by lowering the NUMBER slider.\n"
8 u: i9 u0 K I, F( L$ X "The setup has stopped.")
! g) |% q" t' s2 e stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color7 P1 q# P, k# [5 Z& g
crt num-cars* @7 u: C6 c, E% i k
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setup-cars
) c' y$ p* ?+ T3 O5 `+ x set-car-color
( B" d: l. Q) e* O( s1 ^: }3 B6 j record-data
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5 Q1 n* Q1 I' M! K" W ;; give the turtles an initial speed
% `% C% [0 f5 V: d+ d ask turtles [ set-car-speed ]
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4 A/ W8 s4 B4 y) i! B! X! s reset-ticks
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* m/ W* i" \) e* _;; Initialize the global variables to appropriate values5 p2 f7 \8 R, m. ~( R
to setup-globals
- p6 K+ |/ ~7 o) o' \$ c set current-light nobody ;; just for now, since there are no lights yet
' D1 c( y( P3 \3 v. i set phase 0
$ l5 W2 P r' T set num-cars-stopped 09 l ~ @. w/ g8 l2 |
set grid-x-inc world-width / grid-size-x, @- |: ?0 P2 x
set grid-y-inc world-height / grid-size-y
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- T V" q( d& V4 P# ~6 y* _4 | ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
) ?1 a+ [+ H, ]# z" i4 P set acceleration 0.099+ B' h; W1 v; Q& S! u- o4 \
end
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% g. L" h$ R2 U;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
- o. C! X: a ~& u s8 X' g. } h- D;; and initialize the traffic lights to one setting
- X" h1 M: p% s7 R& ato setup-patches; |/ F* l; h; O3 ~
;; initialize the patch-owned variables and color the patches to a base-color
# y, R' S( k$ D- P. X$ ~, c! S ask patches
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. \3 }0 W: ^+ h) e: Z, l, C set intersection? false$ g! t q8 l9 L( }
set auto? false) I+ _% x4 ^6 K9 j* G+ a) T$ c
set green-light-up? true+ y! ]: `+ `2 R7 W9 n
set my-row -1
m: \1 j. ^6 _2 A set my-column -1
$ v& L0 w1 V' c$ M$ r. t5 z* z set my-phase -1
4 T2 A- {( p$ h set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets, q( _5 d7 `; O7 ?( `
set roads patches with
1 l- ?8 q! x/ [6 p$ g [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or; N# U' R0 ^; @* f5 q) P2 V- h8 `
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]" L% a7 `) ^( a/ m7 ~* f
set intersections roads with+ z4 B* G2 K& `; W6 C A
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and- w9 i/ G) [3 S. h) c/ P5 I! H
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 Y# ?# X. o$ |* j+ J
+ [* d M1 ?' M6 u& v ask roads [ set pcolor white ]
. b% l( Q7 z1 a3 x setup-intersections% s8 P: Y) v' Y) ~( [. \4 ]
end
. s3 T. c0 `/ @3 L2 b& k其中定义道路的句子,如下所示,是什么意思啊?: e8 S/ V4 G$ V9 G8 \
set roads patches with
& T" C# @- ?9 y1 p, k0 [ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
Q/ k( ?4 N- S3 ]% e6 s (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
w8 D7 K6 i( X/ B/ m) y& @4 N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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