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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。1 M& t. ?9 i% J7 ?' b: ~, D9 u7 f4 y
netlogo自带的social science--traffic grid这一例子当中,' Z; x) {: L9 o9 y
globals
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% X. q/ |0 W4 H2 J grid-x-inc ;; the amount of patches in between two roads in the x direction
* y& Q* Z8 Q: Y- }# j grid-y-inc ;; the amount of patches in between two roads in the y direction, {4 H" N! |2 v
acceleration ;; the constant that controls how much a car speeds up or slows down by if
8 f0 f2 v6 g$ {( U* ] ;; it is to accelerate or decelerate6 }+ E* V0 h; b! @- Y5 q7 |% Q
phase ;; keeps track of the phase, y+ `/ d7 c' B0 l" n
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure5 l. c, A# {& W/ t6 b6 X+ o. ^
current-light ;; the currently selected light
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* U% [! K+ S9 L" i# E ;; patch agentsets
2 p. C- U! f% b, W) \ intersections ;; agentset containing the patches that are intersections
* F0 |9 R& v1 l. D* {; g+ u8 z roads ;; agentset containing the patches that are roads
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9 `, a5 ~; ~+ T, K+ u+ Hturtles-own2 u3 m! L/ _5 H1 L2 s1 R/ Q
[
$ G" p2 d4 f2 T+ ~$ d# y2 m k$ X speed ;; the speed of the turtle
# l$ p% _: p! v2 i up-car? ;; true if the turtle moves downwards and false if it moves to the right; f% P2 N; F+ |; H2 R# Q% ~
wait-time ;; the amount of time since the last time a turtle has moved
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) x8 t/ T: R% ?, h/ bpatches-own# O5 X F1 N8 b- s# B% H) C
[
" \# U$ d9 f* p6 n5 d intersection? ;; true if the patch is at the intersection of two roads `* Q. y; _; y* W& h
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
" @& q0 s1 Y: N, M. t2 o ;; false for a non-intersection patches.& V7 E9 l' D& W7 Q& ^9 G# X
my-row ;; the row of the intersection counting from the upper left corner of the
z2 Q& E/ [$ M! w" W8 D, _* j ;; world. -1 for non-intersection patches.
5 Y2 B: z1 j" t my-column ;; the column of the intersection counting from the upper left corner of the b# j$ [5 z( O+ S6 i# x3 P# P
;; world. -1 for non-intersection patches.
9 E, `' d$ w2 k4 S1 e3 t# Z/ X1 y my-phase ;; the phase for the intersection. -1 for non-intersection patches.* p! @ V# S5 b7 s
auto? ;; whether or not this intersection will switch automatically.
3 ~' B3 R9 _. b8 m" @7 h* C" E ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;& p; g+ @- X' |+ ^- R
;; Setup Procedures ;;* \: x+ p( E3 o! V( A! u+ @
;;;;;;;;;;;;;;;;;;;;;;( s- f2 k) n/ e
# t8 N1 n4 q( X% r s4 H;; Initialize the display by giving the global and patch variables initial values. i' ^( Q* ^" O& |- e2 {# j
;; Create num-cars of turtles if there are enough road patches for one turtle to
4 d# O6 M, s" g0 N2 c/ N;; be created per road patch. Set up the plots.# F2 M; |( p8 n% m) M+ Z" R3 A
to setup& B2 t( O6 ]! {' m) M$ n
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setup-globals7 n8 A7 x% o$ ^4 w5 H
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;; First we ask the patches to draw themselves and set up a few variables; y6 A/ {9 q+ p1 {; v1 i& L( }
setup-patches* T0 ~/ v3 N2 V- Z7 H3 V
make-current one-of intersections
1 k; f8 G- Y; ?3 s3 }2 e label-current
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. ^+ N0 D6 }" Q1 ^, o set-default-shape turtles "car"* W _+ [- D8 g% ]0 ~* H @ ]
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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 "
: M( K* N" R% [ "road. Either increase the amount of roads "
8 @; K. R; J8 _; f8 `& R "by increasing the GRID-SIZE-X or "5 @3 {9 Z4 Q9 u% c& D8 n
"GRID-SIZE-Y sliders, or decrease the "( C* e- K! T8 _1 @
"number of cars by lowering the NUMBER slider.\n"
2 x$ y* l S! s% @- d "The setup has stopped.")/ @6 |; ~# k3 X) R9 s
stop9 U4 M- o: X$ ~. z
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F1 G2 o- H c5 c, K* W9 t ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
) j5 i2 j/ ~% ^: Q crt num-cars @) V0 v# g% w, f y, v# W
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setup-cars
2 Z. k. B- m' P; F3 x1 C6 ? set-car-color
8 R/ N3 g) |& |8 O5 U% w3 F" h- M record-data, P/ P( d. j5 @5 ~+ u2 Q u0 I( ~* x
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7 J) ^- X; l7 q2 S: r* k ;; give the turtles an initial speed# _$ m0 D+ a1 g( f2 N
ask turtles [ set-car-speed ]; K1 f* r% _' `3 ^; C
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reset-ticks
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$ F& r0 F8 p6 }) u;; Initialize the global variables to appropriate values
+ a& S8 G2 _! x: b5 H2 eto setup-globals
" q2 y. y% d' ?, h2 l# u; {9 h; f set current-light nobody ;; just for now, since there are no lights yet
5 t! d) M# O: W# s1 G set phase 0; p( b) i" T- i L' U$ X0 L
set num-cars-stopped 0( Q, M9 A* H. _* _% X+ o% r/ u* I
set grid-x-inc world-width / grid-size-x. t; A2 F% {8 L9 B3 X9 c
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 boundary
$ k* _# \5 q) e set acceleration 0.099$ Y$ \- o/ y$ a8 Q' l
end! u3 c* h+ d- c B( h" l% I' p2 k
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,5 Q* \0 K1 X0 L' t0 H6 t
;; and initialize the traffic lights to one setting
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;; initialize the patch-owned variables and color the patches to a base-color% X; ?* W" C% ~! L
ask patches
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set intersection? false
1 D1 z# V- c* n/ R set auto? false( g z4 ~. d9 o2 J6 X( s3 V7 u
set green-light-up? true Z/ L. y H8 e+ _) n3 \
set my-row -1' i- w* Y) S* B. D; R; c
set my-column -1
1 `& y5 s. j2 r. Q. F' Q6 u set my-phase -1
' z! a' b3 ^5 S- p8 w# p( ^ set pcolor brown + 3
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! y( U" ]' x* U+ g2 u8 | ;; initialize the global variables that hold patch agentsets9 G/ _8 `% X6 }, \
set roads patches with
3 O4 o' R) N8 w! x# U3 c [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
`; g- A" A Y, p (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 X7 o2 C; d* c7 K/ x3 c9 {, u set intersections roads with: W! V% [2 B" P# [6 }+ ~
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
0 d* r6 ^. F7 |( D$ {( m* p (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]1 s7 f, E2 S) s+ D; s9 d: Q" e
setup-intersections# k/ t( @9 R" q+ y- }! h4 R
end
' g( W3 s, @3 c4 I& p& p其中定义道路的句子,如下所示,是什么意思啊? s, Y: j8 q& k( N3 x5 e# W- {
set roads patches with
) Q9 B8 _% Q3 T! @& O; }: Z [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or/ L4 T- R8 |6 L1 v* q7 d& m6 {/ f
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 F" P# C" H6 g+ j3 d8 ?3 k
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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