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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。
, `* z+ p2 i( X# y; ?- Wnetlogo自带的social science--traffic grid这一例子当中,5 w! M# w7 d w; y, D) N/ i9 R
globals. {# B* p& i. n2 z
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) k O$ s% O: t9 v: R/ b grid-x-inc ;; the amount of patches in between two roads in the x direction5 X2 k: D! G+ R/ I/ u1 J
grid-y-inc ;; the amount of patches in between two roads in the y direction& ?. I2 D8 _& |+ |
acceleration ;; the constant that controls how much a car speeds up or slows down by if
9 l2 J8 z& U6 O9 m4 }; [7 A ;; it is to accelerate or decelerate
7 Q% E" g. J: ]$ a4 {6 Y phase ;; keeps track of the phase0 Z- G2 e+ i4 w+ b
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure% y" Y; R% g; Q* H/ w/ U1 G) B U
current-light ;; the currently selected light
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! f+ [4 R6 Z; b; t ;; patch agentsets5 v; z: N0 G/ Y/ _2 H* T# {
intersections ;; agentset containing the patches that are intersections
# L. l" B) `2 M- L roads ;; agentset containing the patches that are roads! u& P2 e7 G4 t7 e9 p$ ^6 z
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turtles-own( h7 b) u1 I3 r- ]6 w; R
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; V, X8 }* _6 T+ a$ X speed ;; the speed of the turtle
/ j: a. {* g" ^) ~! m' w/ C up-car? ;; true if the turtle moves downwards and false if it moves to the right
/ q! v( G5 Y3 K, S: N wait-time ;; the amount of time since the last time a turtle has moved6 o) I/ G" \) u$ Y5 C0 o3 t
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patches-own: T( u% @6 {( a# d3 _
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intersection? ;; true if the patch is at the intersection of two roads
E; k' ]+ e! T! Q green-light-up? ;; true if the green light is above the intersection. otherwise, false.
. c( c+ `. Y3 j0 {( H$ X ;; false for a non-intersection patches.
( p) r7 l$ E+ B4 l3 z7 ?* L. W my-row ;; the row of the intersection counting from the upper left corner of the' a- p7 K' K6 T2 P* H G: e
;; world. -1 for non-intersection patches.
2 v' O! ]. ~+ e( U8 A my-column ;; the column of the intersection counting from the upper left corner of the
# ?, p0 v2 K* [4 H7 J1 W- C ;; world. -1 for non-intersection patches.
$ E$ C7 x, F4 { P2 n7 Z- O7 j my-phase ;; the phase for the intersection. -1 for non-intersection patches.
/ p3 [$ q! l7 o6 W. I0 z8 ]# a* @! D0 I auto? ;; whether or not this intersection will switch automatically.
U i" A) K: s& J" @6 }" h7 y: ^# o ;; false for non-intersection patches.8 P8 _7 U- e Z9 p
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;;;;;;;;;;;;;;;;;;;;;;
* W$ V( e' p0 q3 R3 F;; Setup Procedures ;;
; s" k1 S: F+ w2 l. n* L2 B;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
& |2 g% q* X- r; @;; Create num-cars of turtles if there are enough road patches for one turtle to
: `( K' |1 H: @' `+ l;; be created per road patch. Set up the plots.
* p$ A) a4 t" J/ B7 n# Q4 Uto setup
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5 e/ q" d" b4 N) U: u setup-globals
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;; First we ask the patches to draw themselves and set up a few variables7 ?0 p4 N6 |6 I; n( e9 P9 Q
setup-patches
" k7 D3 y* ^$ M. A3 E. T make-current one-of intersections
) z4 r9 K3 T, | label-current
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- y5 _) s5 `$ l! i2 S set-default-shape turtles "car"% n9 q1 ~3 H$ X' t( Z( |7 b: l9 H
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if (num-cars > count roads). ?5 L/ t6 Q1 [; r3 q. Z
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$ `" o7 e7 g0 q) J user-message (word "There are too many cars for the amount of "
( z$ |, e0 ~7 i( S2 \! S "road. Either increase the amount of roads "
j* h9 y# k: j; j "by increasing the GRID-SIZE-X or "
% ^! M) m* ~( | "GRID-SIZE-Y sliders, or decrease the "; C: v1 ~5 H0 u
"number of cars by lowering the NUMBER slider.\n"9 n3 F$ E( R7 ~; R" _/ f O
"The setup has stopped.")+ `& x6 B. L# i: l8 c
stop8 e* i' R2 V- _, i2 R
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! U1 M, @) V# L$ f: v ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
- w8 d( J7 c$ B( F0 D$ { crt num-cars
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+ }! K+ _' R- [ setup-cars2 o8 |9 Q1 w) W9 I
set-car-color
$ v8 U# u7 F+ B9 O record-data7 u. E8 n% Z6 y0 ^% L" W- ?: J
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" [+ a9 {5 p# m6 t" w ;; give the turtles an initial speed1 s' i' c7 R! l3 x
ask turtles [ set-car-speed ]* t- K5 G" n' a
" u9 c" J) u% T reset-ticks
3 J" g# \ ~5 \end
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;; Initialize the global variables to appropriate values0 q* k# p3 G+ `9 N
to setup-globals
+ q# k; T; Y# z. z set current-light nobody ;; just for now, since there are no lights yet
7 ^0 i- C; v2 Q: F. M9 [ q set phase 0
6 A$ s$ ?: D3 @- Q! V) X set num-cars-stopped 07 c7 c! y: J7 Z! Z B
set grid-x-inc world-width / grid-size-x0 q7 q1 M9 A: d$ T2 u9 H
set grid-y-inc world-height / grid-size-y. w$ X/ l& s; S& n* o$ n
7 q2 X& v& U+ d8 G5 E4 }% m! q ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
9 w" J+ \' R- k4 |/ X1 G7 x set acceleration 0.099- h4 Y$ F R4 G
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,/ K" G+ N% `' u4 z
;; and initialize the traffic lights to one setting
! w+ h ~* C. mto setup-patches
2 s" @% U0 M: H5 h: Q ;; initialize the patch-owned variables and color the patches to a base-color% T+ T+ R' q. {1 N
ask patches
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set intersection? false2 X V a& T+ b+ Y( G
set auto? false# v, d4 V9 J% J
set green-light-up? true
, X% i4 S* I$ L0 ` set my-row -1
0 ?) v& L: U, i2 h% Z set my-column -15 x6 P; K; S- O7 G
set my-phase -1
3 |5 @+ s7 B: W9 ]5 R- K set pcolor brown + 35 N8 f. y9 T" K2 {
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;; initialize the global variables that hold patch agentsets
2 q4 |. `; r4 Q! N% ~ set roads patches with ~8 Q& S4 I& r0 j0 q
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 h8 |& S+ j! @# `. _ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
# h. r: Q' n! P- T- @) B8 g set intersections roads with$ d4 S4 n% ~% J3 W9 L
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and8 ~# e( q+ W, N, J
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ ]5 f0 V( l3 D2 X* _
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ask roads [ set pcolor white ]* X% [9 q6 U+ @) k
setup-intersections2 [( C# K+ D. }/ H [, q }" @* I
end- ` {" [' n. v/ P7 N( O; L6 f
其中定义道路的句子,如下所示,是什么意思啊?/ ?' k5 j: ]7 u
set roads patches with/ J) s! t) l1 j* }
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' T3 a) E/ s4 i6 x7 L( z! J; I
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: e% g% y% G3 I( b* N4 }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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