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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。! M! z% d1 X0 Z+ x0 u4 g4 V e ^
netlogo自带的social science--traffic grid这一例子当中, ?$ ]1 X7 D6 `& L) s F
globals
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3 R7 Y! E! T# z grid-x-inc ;; the amount of patches in between two roads in the x direction- d$ P7 y# r. l
grid-y-inc ;; the amount of patches in between two roads in the y direction3 J. s/ z5 [) d" `
acceleration ;; the constant that controls how much a car speeds up or slows down by if9 R0 c! M1 c" N# y. D& T' ~
;; it is to accelerate or decelerate8 _& O& b T( Z8 K
phase ;; keeps track of the phase$ J$ z- N, T& w
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
: Z% \( {$ Y8 t, ^ current-light ;; the currently selected light
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;; patch agentsets
/ q0 O" a; x0 [2 k intersections ;; agentset containing the patches that are intersections4 A3 r; T; P5 C) C; ?* P' J4 Q* m" m
roads ;; agentset containing the patches that are roads
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turtles-own
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0 \/ ~5 J8 G6 G( ^9 E0 h speed ;; the speed of the turtle/ u2 w2 ^7 l: G% g) F5 [
up-car? ;; true if the turtle moves downwards and false if it moves to the right
" i' k* ], l+ ~$ t, [- x wait-time ;; the amount of time since the last time a turtle has moved
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9 s- \6 k, A# w! Y- \patches-own) `, I. w5 p# E% ~8 H9 F8 C
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intersection? ;; true if the patch is at the intersection of two roads
1 J$ N8 q3 C4 P- X! P green-light-up? ;; true if the green light is above the intersection. otherwise, false.. y! {, ?7 X6 F8 [' f% b
;; false for a non-intersection patches.
8 X" v z! H! `5 E1 ^( b' K) x my-row ;; the row of the intersection counting from the upper left corner of the0 [! W+ G, E2 ?
;; world. -1 for non-intersection patches.5 x% |1 Y6 p+ q, p8 H' q
my-column ;; the column of the intersection counting from the upper left corner of the
( ?2 W* n7 }" m* {$ A. x7 A" ~ ;; world. -1 for non-intersection patches.
% z& _; X; O2 W% j6 L my-phase ;; the phase for the intersection. -1 for non-intersection patches.
. K( a: q% |- b ]. I auto? ;; whether or not this intersection will switch automatically.$ Y2 S! H& S2 ~7 |3 |8 V
;; false for non-intersection patches.4 H6 z7 K8 M4 M7 M* T7 t
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5 n, }0 q. P% b5 H9 `! r) [;;;;;;;;;;;;;;;;;;;;;;: I# U3 i) G$ c5 Z
;; Setup Procedures ;;
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8 }6 W- L& T+ R$ M9 e;; Initialize the display by giving the global and patch variables initial values.
* L6 D- E& B: t2 D& u;; Create num-cars of turtles if there are enough road patches for one turtle to: f8 u+ i6 j1 |0 p0 j& H+ s
;; be created per road patch. Set up the plots.; x: v" N: z, Q4 t5 S7 q S' H
to setup
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! a' d% u4 |5 p" k2 j; Y setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
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make-current one-of intersections ~$ F! l/ i' p4 Y0 [, R& s
label-current/ {& @# D# Z% y
- Z5 X2 s- {9 T1 J set-default-shape turtles "car"
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! ]& ^' d# J0 r) i if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
% y3 D2 j+ X Q; f: o) N5 A- o d "road. Either increase the amount of roads "" a: o1 q4 l2 s. y9 @; d; q
"by increasing the GRID-SIZE-X or "& Z9 x0 b* j" h8 l! s- F0 h
"GRID-SIZE-Y sliders, or decrease the "2 ]2 b& e" y \2 J0 O
"number of cars by lowering the NUMBER slider.\n"% T) v+ C: f4 F8 O, @: q
"The setup has stopped.")" K/ l) J6 e* l8 S5 Q$ K
stop% P" I3 K7 G b
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2 t' @) m7 |( c9 w. ? ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
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[
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set-car-color! ?4 ^3 `6 b7 s: n3 q/ h* Y
record-data
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8 ]3 W! A% Q C! S$ z ;; give the turtles an initial speed; f) }: E/ N9 d$ Z( ~
ask turtles [ set-car-speed ]
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reset-ticks- H w6 B( M7 u
end
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;; Initialize the global variables to appropriate values
' ?& A T# p0 S+ e' R9 e9 b0 Qto setup-globals
0 z4 T, L) N! f0 @' V) E set current-light nobody ;; just for now, since there are no lights yet
. S$ B: ~4 I1 m. Y0 L set phase 0! Z+ ?: Q! p' t
set num-cars-stopped 0# ~2 m7 f# Z+ Q+ V
set grid-x-inc world-width / grid-size-x: H) g# y; k8 n6 T- c2 \7 k2 Q
set grid-y-inc world-height / grid-size-y
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. g4 V6 Q" y3 f1 m- V, o* h ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary3 T9 J5 R& _ v( M3 H
set acceleration 0.099+ d& n- B1 w- w
end* e4 b5 D1 O) L) N- u8 {
2 x, f _ v4 T& P. N- w;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
4 e6 s: Q$ T# ^+ m;; and initialize the traffic lights to one setting0 {% l! g: T, \- ^' N' \
to setup-patches
1 A' N4 L1 d9 p9 Y, @ ;; initialize the patch-owned variables and color the patches to a base-color
% ]+ h6 s% t- ^1 C6 S* N$ d" r/ i ask patches
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set intersection? false( Y6 s" \& E: V. L' f
set auto? false& q2 z) h) [: f# }8 A8 n
set green-light-up? true
% y. p Q" K$ u$ V, y6 l set my-row -1
! a4 J. [! K! x3 ^% y% P set my-column -1
- I1 Q2 A+ f, |4 g R( n7 S9 c8 ^ set my-phase -1
/ E' Z* h5 K- x( @9 d8 P! a8 ?0 S set pcolor brown + 3# B) R4 S. j9 Y" L
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;; initialize the global variables that hold patch agentsets v( d. S) Y3 Z. f) {3 m; u
set roads patches with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]' e& Q6 O' c* j5 P
set intersections roads with; Z5 q3 }- I: I5 y9 x4 e
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
j2 K3 a; l- [6 c (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]+ G, ~( @# N3 X1 T( O. u! k. v
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊? Y- r* D E& J: P# p, z
set roads patches with
( ?7 E' ?; h8 v% } [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or- v/ L$ R. w9 p& V6 V0 t U
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
% S: o! d$ B+ { l2 ?2 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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