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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。' j4 s2 b' q+ J) j, o* x
netlogo自带的social science--traffic grid这一例子当中,7 @1 C9 {( u9 A
globals
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1 b* o; [. \; n1 I `* H grid-x-inc ;; the amount of patches in between two roads in the x direction* t; m' i! p" u
grid-y-inc ;; the amount of patches in between two roads in the y direction
6 \: [" H) \5 X0 c2 r( U9 s+ ~/ h acceleration ;; the constant that controls how much a car speeds up or slows down by if
! }/ K5 `' I+ B. v% u ;; it is to accelerate or decelerate
' R6 Q" Y! l& D2 b/ G phase ;; keeps track of the phase
8 r0 `7 a$ Q/ d1 H& W% Y num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure. q3 f9 q& o; u! Y
current-light ;; the currently selected light0 ^/ e( {* [/ k" ^- V# O4 K
$ R+ ]9 w+ c' ] ;; patch agentsets
) W% S/ i! B- T( }' W intersections ;; agentset containing the patches that are intersections
0 }6 _$ p% j c$ Z+ G; D7 I3 Q roads ;; agentset containing the patches that are roads* {) V1 l; V3 k3 t
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. q* @6 S Z5 b, m- q1 Wturtles-own. I% f3 h' ]. v* i; R; Y
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speed ;; the speed of the turtle& R6 s9 A' ~% B" W) x
up-car? ;; true if the turtle moves downwards and false if it moves to the right
# P8 l+ E! R0 f wait-time ;; the amount of time since the last time a turtle has moved2 Z/ O2 {! U' K/ d, r
]
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& L( d8 B4 L, f$ `# ^patches-own' k5 T3 W& p1 G. s. r" q3 r
[
. S; p: Y7 ^$ @3 [0 Z/ l9 I( d# Z intersection? ;; true if the patch is at the intersection of two roads
8 i: V- ]. X/ C green-light-up? ;; true if the green light is above the intersection. otherwise, false.8 I1 |1 I1 \& a. @2 O% }
;; false for a non-intersection patches.
/ H' }) |. a7 ]0 ^$ D my-row ;; the row of the intersection counting from the upper left corner of the
1 h7 J' F- m b) Q6 y8 s ;; world. -1 for non-intersection patches./ s# s; p: V, b2 y
my-column ;; the column of the intersection counting from the upper left corner of the
; v+ q; }. g% l/ H$ o0 Y ;; world. -1 for non-intersection patches.
1 n' E( U3 N; s2 t' q; i6 m0 N my-phase ;; the phase for the intersection. -1 for non-intersection patches.
& w" @% ~/ a4 ?: J& p auto? ;; whether or not this intersection will switch automatically.
+ z4 V' p/ `4 {0 X9 F+ O ;; false for non-intersection patches.
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1 s+ }/ @) z% f;;;;;;;;;;;;;;;;;;;;;;6 P3 J, Q7 b# Q6 L- P2 _
;; Setup Procedures ;;' M1 [, y9 ^7 s
;;;;;;;;;;;;;;;;;;;;;;
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- y. A; [" L. {$ i;; Initialize the display by giving the global and patch variables initial values.$ d4 m7 S4 L, b( Y5 r+ [3 [' o3 r
;; Create num-cars of turtles if there are enough road patches for one turtle to
& J3 H5 T* |2 U$ n- @;; be created per road patch. Set up the plots.
1 M. O) `% w/ G3 F2 x) _to setup
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setup-globals* ?8 C5 [) q& Z/ l @& M
1 f% d/ @8 C: V4 n1 L. r ;; First we ask the patches to draw themselves and set up a few variables( D. ?7 N) ^3 P m- Y* `* u
setup-patches' d- r# g4 H2 X3 n
make-current one-of intersections# q( ? O1 K) `& i2 q* I
label-current
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$ s7 s2 a! H \( \- T5 b set-default-shape turtles "car"
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4 X/ i( f) [6 t% s# w4 L if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "7 \4 N. _& m, K1 W- k
"road. Either increase the amount of roads "
8 {( n/ c: A. i) f' H! ~+ E+ \ "by increasing the GRID-SIZE-X or "
( J* h' [7 D7 H0 c "GRID-SIZE-Y sliders, or decrease the "
3 A: l8 s: D8 f# K6 p "number of cars by lowering the NUMBER slider.\n"
5 K' i3 v9 y$ z6 O: w "The setup has stopped.")
+ \' g$ R3 g& Y: E% Q2 y3 J stop
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; @( m- M$ E/ p/ s4 X ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color# t+ c( i0 i, o+ X
crt num-cars
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setup-cars
: ~( P; o! |* Y- E set-car-color
6 v: [9 F$ k y record-data7 a# P3 D6 E; C2 j$ Q/ [& c
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;; give the turtles an initial speed- t7 V% S# l' M0 P% V$ ~, b
ask turtles [ set-car-speed ]
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; i: l* D# I5 k$ p, A2 ]# Z reset-ticks4 R N9 _1 G( M9 z
end0 ]; r* l! L7 m
+ x9 C' t2 l! K/ U. y! {! @;; Initialize the global variables to appropriate values7 K4 v3 o" }9 n- ]* a: W$ Z
to setup-globals8 a J- u! C. X1 c
set current-light nobody ;; just for now, since there are no lights yet4 G1 h) P. _$ F2 t& y2 V, ^
set phase 0. \0 A; E; U. j8 g
set num-cars-stopped 0" ^- H/ K+ M. m' L8 U4 k
set grid-x-inc world-width / grid-size-x1 E t9 q2 U% ~/ p# {$ h, P
set grid-y-inc world-height / grid-size-y
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: ~0 P: s& E( R ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary# W+ h, t, T- f5 s
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,) ^& c) H/ j1 c2 |, l3 \
;; and initialize the traffic lights to one setting2 E5 F2 R) k# R, ~& q
to setup-patches+ D9 k0 `" o! ~' Z8 J0 W2 b* e( B
;; initialize the patch-owned variables and color the patches to a base-color8 O: K2 x) @- R3 J1 c
ask patches
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set intersection? false
% j5 b4 K+ S6 u5 i) n# q set auto? false
$ z0 x* R* P2 w5 u! | set green-light-up? true
$ ~9 R1 H% F* d set my-row -1
$ t) c( U3 L* M$ s7 e1 l; j4 @ set my-column -10 W! Q$ f! v1 S' U
set my-phase -1
( ~3 i9 E0 N6 V set pcolor brown + 3$ `- o- s: Q! k5 j J5 r
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;; initialize the global variables that hold patch agentsets
1 b+ I' `! |1 Y+ [! W; k0 @4 g4 l set roads patches with2 g( N( r7 ?' F- x
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ Q% }& c; l9 }" g! i9 T `, ]' \) i (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
- [+ _! n5 q# C set intersections roads with
4 H$ e6 U8 A: l/ J; _& u7 } [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and: {+ }8 H0 D$ A% i5 s X4 B' b
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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% i6 A% B+ i+ c7 O ask roads [ set pcolor white ]
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6 P% W4 x5 H/ X p. Iend% G# X8 F1 n$ }1 r
其中定义道路的句子,如下所示,是什么意思啊?9 w) F V: Q* V. |5 a- n
set roads patches with/ v4 ]% J2 Q, s) D
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or5 Y ~' K" q) a) ]" q5 L
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 y2 Y) T/ {7 J9 X1 F6 E7 R
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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