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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 n9 t" n6 B
netlogo自带的social science--traffic grid这一例子当中,
0 v- J6 M% L C1 f) O: F% _; [globals6 W5 C m( e% L0 g
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$ b6 l$ G1 v# p& V- J% b9 p grid-x-inc ;; the amount of patches in between two roads in the x direction
( ~4 W. [/ V q B) g3 I( V- s grid-y-inc ;; the amount of patches in between two roads in the y direction- `7 N' T0 M* Q& C2 P8 N6 e
acceleration ;; the constant that controls how much a car speeds up or slows down by if0 k7 u ]- ^6 D6 D1 z
;; it is to accelerate or decelerate1 f, }& f: x" d/ |7 T, F
phase ;; keeps track of the phase3 k7 N: I6 d' r$ f
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure; {, K6 A0 k" h! C" ?: a# A8 m* w b
current-light ;; the currently selected light0 [3 M' X5 L& {! q& t3 `8 S5 d4 u" J" T
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;; patch agentsets
7 R0 q* u: F, i4 _6 o" V intersections ;; agentset containing the patches that are intersections# S# O& H0 G7 G* I( c
roads ;; agentset containing the patches that are roads( y5 o% E5 C$ ~# P; Y
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- u4 t! R. b7 Dturtles-own
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/ B# {" @+ p* g6 ]5 Q$ y+ U% ` speed ;; the speed of the turtle
! h6 E' F7 t6 Y e7 G% T- s; W up-car? ;; true if the turtle moves downwards and false if it moves to the right. e$ v( H O7 s# Q* E# H+ U9 [
wait-time ;; the amount of time since the last time a turtle has moved
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0 z4 `5 X5 v0 A+ Gpatches-own% p, R( h3 O0 Y' q% _ q
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intersection? ;; true if the patch is at the intersection of two roads/ L% i; Q# ~( D5 I# x
green-light-up? ;; true if the green light is above the intersection. otherwise, false.' n! d9 X* a$ {# c( w0 b% ]
;; false for a non-intersection patches.
! p) W2 [8 d$ P my-row ;; the row of the intersection counting from the upper left corner of the2 a/ \. R/ b x0 E( y5 w3 s
;; world. -1 for non-intersection patches.
# I, S/ c! s, U my-column ;; the column of the intersection counting from the upper left corner of the
# l2 I' Y4 p2 ~6 d7 W ;; world. -1 for non-intersection patches.% D1 T2 Y- \, C9 G
my-phase ;; the phase for the intersection. -1 for non-intersection patches. T# d ?9 C# }
auto? ;; whether or not this intersection will switch automatically.
, A8 _9 I4 q$ K: ` ;; false for non-intersection patches.+ {5 _* E& f' z3 k4 I) H+ ~! S
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;;;;;;;;;;;;;;;;;;;;;;8 X+ A# V8 o9 b" s) o
;; Setup Procedures ;;( U1 l5 O: V/ V) b
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
' z2 Q: z; T s. g5 i" l! e;; Create num-cars of turtles if there are enough road patches for one turtle to
2 W6 k# |9 G9 i- g; U+ U0 A;; be created per road patch. Set up the plots.
) t( G8 Y$ K& m% F* Hto setup( K' ^: D+ J$ O2 Q% E3 m& E( Y
ca; Z. z; r: x y! S
setup-globals
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* i8 k8 O' K U" y ;; First we ask the patches to draw themselves and set up a few variables% ]3 e! K Q& u/ q, I/ t
setup-patches* ^0 n+ `6 t1 M: `) P8 Y3 C
make-current one-of intersections4 j) S3 j0 X0 q3 {# j
label-current, W6 j6 s0 D$ o+ W8 a
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set-default-shape turtles "car"4 g/ L* s* I% x
/ G. f# E7 G, M+ ?* ^5 H" ? if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "# o* M) g1 c/ C' I v
"road. Either increase the amount of roads "
7 }9 T6 O2 M4 G4 o& W "by increasing the GRID-SIZE-X or "
8 ^- w; I6 _: k6 E F7 M "GRID-SIZE-Y sliders, or decrease the "
4 z) I$ f+ C# \3 ]0 `& V* O; s "number of cars by lowering the NUMBER slider.\n"
- L7 T$ L& {3 N. p "The setup has stopped.") @6 W7 T; Q+ k! G9 ~. H- Y
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
5 d2 {" I4 B% B7 `, l crt num-cars
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setup-cars
" V' g" {: Y; Y6 F3 q5 _ set-car-color
0 R2 V) t+ j v9 g' l record-data3 j1 ^) ^3 p4 H- S. G( Q
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;; give the turtles an initial speed% ^# T W& N1 }1 c# X
ask turtles [ set-car-speed ]3 w$ A0 f& ~' Z. r) ~ E9 z
/ F! C! p, N9 o6 u8 V6 l reset-ticks
) W6 ]2 Q0 s0 U9 r. ^end
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1 r O. L/ |; I: I( J7 O;; Initialize the global variables to appropriate values- q) L% y5 a6 ^5 v& F
to setup-globals4 G& |8 p! i' T& c
set current-light nobody ;; just for now, since there are no lights yet6 p K5 X2 ?' o# F
set phase 0, W2 ?8 ?* R* C1 x8 |
set num-cars-stopped 0
; S& w% @. D9 j6 _; o4 t$ X set grid-x-inc world-width / grid-size-x, m+ p2 ?5 g: r- t
set grid-y-inc world-height / grid-size-y8 K/ Z5 `( C0 n9 R' a! Q
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
& J3 U8 {' }1 d* F- r set acceleration 0.0994 ~; \3 T0 x; |. V
end+ `" q9 |' c! F G2 h
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
' D- ^8 t3 x$ F+ a9 ^+ j- v( V;; and initialize the traffic lights to one setting
) ~# d$ \7 M; Y5 p8 ato setup-patches
! A* L( m" x' p, J ;; initialize the patch-owned variables and color the patches to a base-color3 }. Q( F, Q" R* j& w" p( I
ask patches5 z j- [8 B( _0 ?$ H5 h0 i! k
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set intersection? false
, Y$ r( Z( N; e set auto? false6 U( s$ d8 P' p5 V5 }' z1 h
set green-light-up? true# t! G* Y- j. n8 _9 f6 e$ e
set my-row -1" G% c7 [1 i: V2 G8 Y9 P9 [
set my-column -1
; K& P; R) n( z: @5 m5 k set my-phase -1
6 y0 R+ u ]# u# }9 q( R" Y, W set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets7 |9 e% l; I- _# @
set roads patches with
) p' [$ t: G% p' N [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 O6 O5 K, n% r% k0 A" X6 P
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]! U; {: K; | p3 `7 L
set intersections roads with5 }8 Q1 k( V( L. t2 U
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and- q k3 {" ]/ n0 B1 G
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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2 j' x1 y9 P) _) f) A) M$ ] ask roads [ set pcolor white ]
* L+ d9 K' W( F6 S. ? j setup-intersections$ j2 f' P8 d# S0 u, I. m+ a6 R9 X
end; W2 G& X. F+ l# f
其中定义道路的句子,如下所示,是什么意思啊?1 D, b* y% v, b. l" R6 t
set roads patches with( T8 S y( h2 d& h
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
* o/ \& @/ I' s5 T (floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 |) I8 p* g. V0 V: P5 s# C) 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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