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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。0 W) n; F6 G3 z- G
netlogo自带的social science--traffic grid这一例子当中,* n: r- }# [6 ~! g# S* I* Q$ M
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' I! O+ o( g! G, ^2 } grid-x-inc ;; the amount of patches in between two roads in the x direction
/ L! t' J ^( N# v- d grid-y-inc ;; the amount of patches in between two roads in the y direction
1 f6 X8 N% G* {( q0 [+ t' @ acceleration ;; the constant that controls how much a car speeds up or slows down by if
' ~, {. A& b+ c/ q2 ] ;; it is to accelerate or decelerate \: _) F. o& c( p! g
phase ;; keeps track of the phase
% }" d/ j) [6 s c7 z num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure8 ?+ `3 N8 j9 J' i, P- a6 u" \
current-light ;; the currently selected light2 ], C' L: z7 W2 c% k
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;; patch agentsets
$ o2 A/ U" D3 n2 r1 U' n intersections ;; agentset containing the patches that are intersections( T- I( x8 H2 {' @ C1 ~
roads ;; agentset containing the patches that are roads1 i0 ]+ M8 I9 M' n& x& ]# Y t
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turtles-own
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speed ;; the speed of the turtle
% N, {: e) P$ \; a4 j5 G' [ up-car? ;; true if the turtle moves downwards and false if it moves to the right1 i) @7 \9 M) ] P ^% x
wait-time ;; the amount of time since the last time a turtle has moved# T( A4 P; w' s! w2 T! L8 i1 A
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patches-own0 m" `$ ~" P- E
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6 L, D# F. }' ^$ v5 T+ H3 ^ intersection? ;; true if the patch is at the intersection of two roads7 t, R b# z( |* f2 S2 l
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
, L* v/ p$ D* U5 I; F ;; false for a non-intersection patches./ p9 k( L0 R4 ^" T
my-row ;; the row of the intersection counting from the upper left corner of the2 w2 y& u. r- ^, G
;; world. -1 for non-intersection patches.
4 W g2 t9 Q. |+ Z8 e d7 w my-column ;; the column of the intersection counting from the upper left corner of the0 T1 F( x+ J6 E, E0 N# T/ M, N
;; world. -1 for non-intersection patches.* z: O& q' v/ K; J) C. w, ?* Q
my-phase ;; the phase for the intersection. -1 for non-intersection patches.: Q1 Q D- d7 g" c9 f+ C$ c! [
auto? ;; whether or not this intersection will switch automatically.
8 I# {. F2 _! C* c1 q& X1 t ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;" _- r5 O. r4 q8 A; h
;; Setup Procedures ;;
1 Q4 V, Z. o% o8 n; L2 I;;;;;;;;;;;;;;;;;;;;;;
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6 C2 ~7 @5 C M- u;; Initialize the display by giving the global and patch variables initial values.* ~3 l5 ?5 a2 |/ ` T7 {3 Z4 k0 J
;; Create num-cars of turtles if there are enough road patches for one turtle to
4 O4 [2 N7 t& k2 B% \;; be created per road patch. Set up the plots.
: I, w2 ^! k( M$ y. L8 x% j' r' Hto setup1 c9 B' B" }& C) Y; u; \4 O
ca
8 i) X. v( a- G5 D+ q* l) i setup-globals
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4 h: X) l0 P. G6 i2 i" q |$ L6 _ ;; First we ask the patches to draw themselves and set up a few variables
) }3 g8 B, f0 R a setup-patches
4 t9 _5 |% `. H+ }& `0 @4 C" [ make-current one-of intersections4 }! B% a3 P4 O) k9 Q0 R
label-current
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5 H" w \8 Y$ N set-default-shape turtles "car", p) r( q" h+ C9 K' A' x5 j
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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 "/ O( K7 H. ?- N2 p5 N
"road. Either increase the amount of roads "+ x+ E; @' C! K% v2 n
"by increasing the GRID-SIZE-X or "
: J5 B7 d Y- z% L) q& T. u3 I6 ], ~ "GRID-SIZE-Y sliders, or decrease the "
( \: t' |- P6 G! T, O "number of cars by lowering the NUMBER slider.\n"
, U9 F/ L+ X' m% o g# y# a0 c "The setup has stopped.")
; `' Q' o# @0 X! U" D/ y8 k stop" Y3 \7 i# M0 m+ b3 F
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
* {4 x+ P" m& I3 S crt num-cars. T% y9 u2 S! T
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setup-cars# I! m$ w9 D, t* X2 u4 }
set-car-color
( R2 _ m" l! i# w) ] record-data
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- B8 O: W" ?* A: P ;; give the turtles an initial speed
, D4 [2 G9 s) N7 _5 R ask turtles [ set-car-speed ]1 g8 f% }3 R2 G9 R; v+ g
. @5 ^7 W! C0 t7 N4 _4 c& ` reset-ticks* U1 M) e% t8 W* Q" k* D
end
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4 `6 S; _1 K* |4 I) [/ D;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet+ @9 p+ Q0 Z/ K8 D1 G7 I
set phase 07 ]9 z+ w) j8 ~! B) ?- J
set num-cars-stopped 0
0 T$ e% y, z* ?; Z set grid-x-inc world-width / grid-size-x r. J# Y$ _. e7 S8 B& h# Z
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
! e8 q8 V6 K! F5 P set acceleration 0.0998 P/ e( W, l6 P: `
end) z/ l4 E h; d' ~% u
$ P. c9 h1 V3 i+ f, y9 \# ];; Make the patches have appropriate colors, set up the roads and intersections agentsets,
8 ?( h1 ~* k7 S8 Q& z* E# u$ c;; and initialize the traffic lights to one setting
: X- {2 ~' F" h( Q- ?to setup-patches) g$ [4 O: X) t+ ]. d& l. j
;; initialize the patch-owned variables and color the patches to a base-color- h4 w! |0 l( X
ask patches* M; J7 t# p9 u9 P
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set intersection? false- Y+ d# u9 [# o+ q/ R
set auto? false3 v B7 w# c) e" d! ~
set green-light-up? true5 x0 m9 s& C) y P# G
set my-row -1! v, Q' U* _7 y5 @! L6 B6 L
set my-column -1$ b3 C3 l1 i- P" K( |4 b1 @
set my-phase -1
A% h! X d7 }; q* _* w: S set pcolor brown + 3
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3 N: j) M! S/ e1 T ;; initialize the global variables that hold patch agentsets: G" P6 W+ \3 k2 |- u$ ~% [
set roads patches with3 n7 _- [# Y3 u
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% Q: j3 c# U+ n
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 t) w- t( x6 P& E7 q% _, K set intersections roads with
' L9 c! y0 ]2 x U6 H+ I [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and) i4 z4 V- j) Y( X" P
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]# }" }/ \5 Q5 J4 C5 t1 F% t6 W& q
. P N1 F- L' o* h2 B1 B6 f ask roads [ set pcolor white ]* R; Z' X( \) t0 ^2 _
setup-intersections) [0 M/ Y) h; E( `; G/ k
end6 A9 B1 ^* I; z1 n" d" v" Y
其中定义道路的句子,如下所示,是什么意思啊?$ I( K6 X* S# [3 D ~8 a+ s
set roads patches with, W! \7 ]1 M9 |/ P
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or; \5 k5 v1 U- a
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ ~% I0 A7 [! l9 L! |3 U; X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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