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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。+ w' ^0 x' V9 c! I# p# y9 ^ x
netlogo自带的social science--traffic grid这一例子当中,
' }1 W* @- g. y' m' F+ P/ m' vglobals$ s& L+ a, C/ J: O2 P
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4 G1 }) ^0 ?" q Z% r grid-x-inc ;; the amount of patches in between two roads in the x direction, s$ b7 { h' h+ T Z( q+ c
grid-y-inc ;; the amount of patches in between two roads in the y direction
! Q3 e. u: B9 f' T; E acceleration ;; the constant that controls how much a car speeds up or slows down by if
0 X( p s" `3 m1 ]7 S& J+ W8 I ;; it is to accelerate or decelerate* T4 i3 D. Z% S
phase ;; keeps track of the phase
1 x, ^6 j6 ~7 T7 e2 x num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure0 b( C& c- Z( e- k% H) Q* L! D
current-light ;; the currently selected light! P! b* O2 t% z/ R- F s
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;; patch agentsets
. _& F( W" I# t* X. M7 Y0 W7 U intersections ;; agentset containing the patches that are intersections7 X$ j, Z1 n9 ]2 j; [; B
roads ;; agentset containing the patches that are roads
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- f/ v! p8 d; fturtles-own! W2 x" E" B' Y _) J" Y
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8 h; t$ t% g' O! Q$ o speed ;; the speed of the turtle9 b: s: Q9 J/ ]0 z* i2 W0 J# V" i
up-car? ;; true if the turtle moves downwards and false if it moves to the right: p' b6 a% Y8 G3 J: h+ h8 h
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
, S2 f# O( q" ^! ?" E, o green-light-up? ;; true if the green light is above the intersection. otherwise, false.
, R" v, g* ?( x5 Z! [2 H4 { ;; false for a non-intersection patches.1 z3 c$ M" a* l0 h
my-row ;; the row of the intersection counting from the upper left corner of the
9 R( N; `: n% \* z3 B4 l, S ;; world. -1 for non-intersection patches.2 Z4 Z( `! q+ p% M
my-column ;; the column of the intersection counting from the upper left corner of the/ ^; {# V7 J m2 k# T" s/ M/ a/ z$ X
;; world. -1 for non-intersection patches.
! B6 _, ^& N7 J9 x my-phase ;; the phase for the intersection. -1 for non-intersection patches.
1 U" D1 S l1 N8 F8 l& y auto? ;; whether or not this intersection will switch automatically.6 F2 ? X" q+ l
;; false for non-intersection patches.
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- x$ n- Z/ `7 d4 t9 s" F5 |;;;;;;;;;;;;;;;;;;;;;;
0 r( j( X- j! w6 k* D5 P) Z$ y;; Setup Procedures ;;
, k: ^8 I _% b5 X;;;;;;;;;;;;;;;;;;;;;;2 w6 S3 G5 R" N0 ]; d( a
: y7 L- p r( ~7 d# q;; Initialize the display by giving the global and patch variables initial values.
# p. |/ I* p% V) |) I/ [- P;; Create num-cars of turtles if there are enough road patches for one turtle to- q9 n$ V" b; }& s8 G7 f; G
;; be created per road patch. Set up the plots.5 p7 B) l& r% z( c
to setup. j( W2 n x5 D& r* u: [
ca
) H% p, \6 L0 `$ f% K setup-globals6 f1 s, z, T3 P8 }+ A0 R0 T7 ]4 n$ X
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;; First we ask the patches to draw themselves and set up a few variables9 \, M, v2 U8 T
setup-patches& k6 q5 h, G* j; U
make-current one-of intersections
7 C) J3 h; u$ B! p. Q label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)
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8 p- A) R- r* n; t8 p! O3 C user-message (word "There are too many cars for the amount of "
* m* R/ d7 h) H, Q/ p& A "road. Either increase the amount of roads "
! e: p. Z! r$ E8 G* {9 Z "by increasing the GRID-SIZE-X or ": A* W! t6 l% |/ Z0 O
"GRID-SIZE-Y sliders, or decrease the "8 E) r, D' c7 |% ]
"number of cars by lowering the NUMBER slider.\n"% E8 z( c: L5 t E
"The setup has stopped.")
# Z( w: t7 P7 m3 Q! _. I stop; F" I! n8 k- z5 w A1 n6 `
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0 G: a' q7 Y9 @/ }' V$ ? ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
( `: J$ y1 n5 d% z$ _- c crt num-cars( ]! a: \+ T) w1 l% {: N& a6 Q
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setup-cars9 M8 t, b) \0 {3 J+ M; \
set-car-color
% A7 }4 i% H( w7 v record-data
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;; give the turtles an initial speed/ N2 [* Z' Z( M8 y6 y1 `& V
ask turtles [ set-car-speed ]
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6 K6 d) f% w5 Y9 @ reset-ticks
+ d& o! F$ z5 G& oend
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;; Initialize the global variables to appropriate values
% `$ v/ v& S1 o8 j* _6 \to setup-globals
- n/ L9 y- s" h. d2 H, E set current-light nobody ;; just for now, since there are no lights yet3 K7 a! o/ I& p- K
set phase 0
5 ~* ?! l2 `% A set num-cars-stopped 0/ {1 M K4 n; G' k/ X7 ?
set grid-x-inc world-width / grid-size-x" [3 I/ N+ ^$ p
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 boundary6 i! _: D: l# T; q3 `8 W& B
set acceleration 0.099
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% T; }2 C' d9 Q2 R* u7 P7 C;; Make the patches have appropriate colors, set up the roads and intersections agentsets,- T9 J* t; g9 H# |9 Z. f/ P
;; and initialize the traffic lights to one setting
+ P1 ^0 c5 C: x- T: wto setup-patches2 t% N9 ^* p# M1 E/ i# s) ]+ b0 o! S
;; initialize the patch-owned variables and color the patches to a base-color& y$ h) z5 r3 A& N- O
ask patches( u5 B3 ?0 `- n4 U- z
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+ E8 O2 _ Y' M set intersection? false3 F; f, E [/ ]* Y& ~% a
set auto? false4 K4 {5 F5 q" F6 N% m/ e2 Q/ _
set green-light-up? true
0 ?3 X3 ]6 V9 C0 Q3 ^$ ~$ a# ] set my-row -1: M' `# e+ }, g; e5 D8 A5 B7 C
set my-column -1
! q0 j o8 Z2 r set my-phase -1
% Z$ ~! s7 _4 v7 m set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
, j. s. f1 d3 \6 h* m. ]: j set roads patches with* V. X1 k' z) J( B( A; Y. f4 C
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
* E9 e0 x: _' X1 m* J8 D) z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]* F5 I# N- `: q& X
set intersections roads with
6 Q6 {$ D, b8 }: v( c& e' I) f! U5 Q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
5 f9 a; X1 N! L3 c- A6 N/ c% V (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]7 m7 w; c! g2 }! `& ], J
setup-intersections. j7 A [$ n* a
end+ O( g5 A" Z2 J# v+ s& ?
其中定义道路的句子,如下所示,是什么意思啊?
: Q7 F" s+ t5 h; ~8 F5 I set roads patches with% D* g3 N: v: z9 | P* k
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 n: k$ r' a0 h) Y7 P6 b1 x; I) v7 x (floor((pycor + max-pycor) mod grid-y-inc) = 0)]; [! o6 e9 ]/ x- X1 m& s
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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