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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。
6 C; \! t4 i1 [. q2 ]6 v2 T# Qnetlogo自带的social science--traffic grid这一例子当中,, b2 l) w5 ^& [& Y; f; f& G2 p( n
globals
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! p0 H; \' f6 i( T$ Z5 }8 A# F grid-x-inc ;; the amount of patches in between two roads in the x direction
% u1 N- h1 L; c/ i$ n grid-y-inc ;; the amount of patches in between two roads in the y direction
# r) V/ e( h1 A acceleration ;; the constant that controls how much a car speeds up or slows down by if1 D5 L* {8 Q$ w) g
;; it is to accelerate or decelerate# r, U% r: G2 Y
phase ;; keeps track of the phase
9 Z$ Q1 f" G% @ m; R7 r& }8 L- Q/ N- m1 R num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure" H* ~% m: Z: P3 Q
current-light ;; the currently selected light$ @5 ?8 k. L8 b: \
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;; patch agentsets; n6 A0 }' y1 T! `/ `, i' P$ \. f
intersections ;; agentset containing the patches that are intersections& n4 w) f! a9 ~3 U+ Y4 R
roads ;; agentset containing the patches that are roads
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turtles-own
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1 N; d! A( ?1 _: G4 Y( X speed ;; the speed of the turtle
/ v4 h5 m1 j. a) `* E up-car? ;; true if the turtle moves downwards and false if it moves to the right% u4 d$ L# b/ h" [- r3 C5 I' F
wait-time ;; the amount of time since the last time a turtle has moved
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5 K+ q! w, e+ [. {! [: W* jpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
" ^, E& o# R" H) c green-light-up? ;; true if the green light is above the intersection. otherwise, false.
: S+ l$ V% d8 ], s ;; false for a non-intersection patches.4 K4 A- f' P7 Y2 C
my-row ;; the row of the intersection counting from the upper left corner of the1 C! Y1 \% Y' c+ w, Q- p; p9 y y; \
;; world. -1 for non-intersection patches.7 m/ |3 U9 b* S, ^# y
my-column ;; the column of the intersection counting from the upper left corner of the- h U2 s7 w- l9 m. |
;; world. -1 for non-intersection patches.
4 U; k$ t+ u9 ^- A my-phase ;; the phase for the intersection. -1 for non-intersection patches.. x" j2 g; c4 Z8 \2 l9 J9 _
auto? ;; whether or not this intersection will switch automatically./ L1 I% h: ^ @, M
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;$ \: r( R3 Z; [% z6 N5 k
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.' D# p \: p" r( c
;; Create num-cars of turtles if there are enough road patches for one turtle to( I; U _4 L& ]
;; be created per road patch. Set up the plots.* N, R# J' g6 g" u
to setup
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, q' f% L& d$ ? setup-globals
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! v/ _* \" P# ]8 M6 j1 t ;; First we ask the patches to draw themselves and set up a few variables
) g! R2 b" K5 ^7 T setup-patches
0 g8 q# A" e4 y make-current one-of intersections7 o- _7 E& ?' V6 y7 m
label-current
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# E* V# o% r/ `% g+ a' {" ^7 ~ set-default-shape turtles "car"
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if (num-cars > count roads)! B# W+ t% U2 F* |4 b. ~1 u/ o
[
1 t5 ^4 ^1 \* E G" k user-message (word "There are too many cars for the amount of "
6 e2 h/ z8 K: n8 H$ x) w1 |9 g$ d2 S "road. Either increase the amount of roads "
0 b2 c: ^2 J7 |( ~ "by increasing the GRID-SIZE-X or "/ V$ f% H- U- c& ?, x% p3 w
"GRID-SIZE-Y sliders, or decrease the "
- v) I* E+ M% V* H "number of cars by lowering the NUMBER slider.\n": f% C% _1 k8 a( i
"The setup has stopped.")
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color) s) n2 P; |+ P
crt num-cars
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setup-cars
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6 k y y: q8 d" R' \ ;; give the turtles an initial speed* t4 H6 y- I& w/ b* S
ask turtles [ set-car-speed ]
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reset-ticks! e8 j% _, ~$ J: ?* K$ b1 \
end
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( E9 \+ Q( Z1 F;; Initialize the global variables to appropriate values, ?- e" z% J% [$ {$ C0 i
to setup-globals; J# v) e s/ z) v
set current-light nobody ;; just for now, since there are no lights yet8 _ |" E8 m) _: l0 Z, {7 s2 h
set phase 0. G1 ?# b- Q! M7 z4 ` t- H
set num-cars-stopped 0
; |# h, R0 c& O y0 C3 s set grid-x-inc world-width / grid-size-x% `6 [, d! A( E$ b# L
set grid-y-inc world-height / grid-size-y2 b8 [9 z. g3 r; C. I5 u7 ] {& F( _! |
5 z P1 @1 i" A d ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary2 e6 t; L* T: E- Q0 ]
set acceleration 0.099( U; Z! D; ]4 D
end' \6 p. P% s! c) ^; `) G4 @
. [' v4 K! r. W9 c' n3 l: x;; Make the patches have appropriate colors, set up the roads and intersections agentsets,1 W$ Y2 x7 i1 a5 _
;; and initialize the traffic lights to one setting
5 y4 H2 D$ j' |8 O& t9 Fto setup-patches( C& j! C9 G _6 G7 Y) |: H' J
;; initialize the patch-owned variables and color the patches to a base-color+ F5 D& b8 R* z( l2 H, l" N
ask patches2 W' ~8 e8 H5 k
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set intersection? false
2 t, {) D) X# x2 S( R6 B0 a! A) }( I1 r set auto? false
) m, T' O! ^. {+ J$ d set green-light-up? true
9 a0 K) D F3 |, h; \6 q& A set my-row -18 ]! C; ?6 o- K/ d7 O8 w4 E: J
set my-column -10 f# b+ q, p7 V6 S M' `; W
set my-phase -1+ a4 ]4 @; b4 a1 L/ d
set pcolor brown + 3& m5 {5 W- L( p$ e8 b+ t! y9 ]1 g
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;; initialize the global variables that hold patch agentsets
! E8 y" e) T7 [- O2 R$ L& D& D set roads patches with
1 T2 ^# @+ t' [! p [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or! V. W* V# o) _ _- w
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
8 o( r$ ~1 E$ ^& j f. y7 Y \ set intersections roads with: u( V' ?' L! d6 e" A
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and/ }( u3 w" r" r3 r, C+ n
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]4 c+ o0 q4 d( B5 t; h$ z2 b# G
( X Z5 S3 O( N1 V ask roads [ set pcolor white ]5 W& j6 x1 N) u8 [7 U0 U0 S& p
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?
. w2 y" \) g" \ set roads patches with
# V4 r1 g" n% R1 M4 t+ [ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
- g+ }! z$ @% p; E% q2 W (floor((pycor + max-pycor) mod grid-y-inc) = 0)]. L+ b# C4 a" A% B: Q8 \' C
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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