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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。4 T0 g T1 Q" o) S8 F1 _
netlogo自带的social science--traffic grid这一例子当中,2 u: N* d9 Z- i. D: y
globals: T2 @$ i, B% [2 H, Q
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/ J& }% L4 n& H E5 ^ grid-x-inc ;; the amount of patches in between two roads in the x direction+ _' H# b0 d( M( D6 z
grid-y-inc ;; the amount of patches in between two roads in the y direction
' {' ?, t( P' ] acceleration ;; the constant that controls how much a car speeds up or slows down by if
1 c }- I; t7 b. V2 [+ n ;; it is to accelerate or decelerate9 Z% {# d9 l3 I6 k" ]
phase ;; keeps track of the phase! ^% E2 O" f7 Y; S
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure1 j% D4 b" s+ g$ j7 ]
current-light ;; the currently selected light1 ~+ w' w' V( S
# \4 a ^! j2 C8 ]1 h. A ;; patch agentsets
% k. L' j+ u. n7 X! m intersections ;; agentset containing the patches that are intersections
+ a3 Q. I# d# S8 A# ^ roads ;; agentset containing the patches that are roads8 x9 g$ V3 \8 I$ h
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: J# x2 n4 y# W$ I2 E% X) I% Qturtles-own
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% d% z* B: T' {" a# T/ ? speed ;; the speed of the turtle9 C$ y$ Q! i; V# [
up-car? ;; true if the turtle moves downwards and false if it moves to the right6 g) E' D) W5 Q+ m+ {" q w; x( Z
wait-time ;; the amount of time since the last time a turtle has moved, C# _3 z; j2 [6 m. {
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0 Y2 N2 @) n' p! E- T9 cpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
: I$ Z. N R' H green-light-up? ;; true if the green light is above the intersection. otherwise, false.
5 B# x: _+ D9 e* d/ [! ], O" g ;; false for a non-intersection patches.
) q" ]/ ` s2 |6 p' h my-row ;; the row of the intersection counting from the upper left corner of the5 E6 k" @+ S+ A( I
;; world. -1 for non-intersection patches.
1 a& h8 ?& ?+ j, p; n# ^" } my-column ;; the column of the intersection counting from the upper left corner of the
9 r" }8 P0 Y2 I- d( v ;; world. -1 for non-intersection patches.3 s, t$ ^: m7 N7 _ a( Y5 ^* ]
my-phase ;; the phase for the intersection. -1 for non-intersection patches.: ?! U. f4 p0 Z* |
auto? ;; whether or not this intersection will switch automatically.
3 A( | i1 u% q ;; false for non-intersection patches." `8 M: ]7 E9 G0 ^& n# v7 [
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;;;;;;;;;;;;;;;;;;;;;;
2 o) S( W& u# p I& {3 P( P7 a/ z;; Setup Procedures ;;
7 L% K) q$ j% j0 m, e;;;;;;;;;;;;;;;;;;;;;;
4 z$ b) \1 r8 G3 m
; [! }8 o3 v9 ]2 J; N;; Initialize the display by giving the global and patch variables initial values.
5 o( J3 i3 s0 l( D3 ~5 Q* j;; Create num-cars of turtles if there are enough road patches for one turtle to
( i! S" @% {% \;; be created per road patch. Set up the plots.; _" r) d6 k8 q% b1 ?6 O" ?
to setup) N) A5 _2 H* B. H5 }
ca# r( ~( J/ x( ]- R3 G7 e
setup-globals
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: |: h6 b# {' t: } [* A ;; First we ask the patches to draw themselves and set up a few variables
' S! F- f4 d2 B setup-patches
. q) M: i4 A* v. p- E make-current one-of intersections+ p! h6 t2 }# E# X: f2 R
label-current
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. q* m' }, Z+ y3 l( z3 g set-default-shape turtles "car"( ^& [8 b* F" j9 r
9 K) B+ z2 t0 b: c: g8 M6 z8 U if (num-cars > count roads)/ ^6 k2 b( B$ f2 u% q/ c* q
[
1 I3 y" A: Z% ]( b* E% G$ H9 } user-message (word "There are too many cars for the amount of "
: d$ ~$ j/ [4 O: Q* l3 s9 j "road. Either increase the amount of roads "' Z0 e- E; ?2 E- Z
"by increasing the GRID-SIZE-X or "+ {( Y6 g. P. c9 d5 J. V: j
"GRID-SIZE-Y sliders, or decrease the "+ B% `: b1 l' r& U3 K: Y# J1 Q
"number of cars by lowering the NUMBER slider.\n"! A6 m2 d$ V# x# Y9 n
"The setup has stopped.")% ]6 `' T9 D. X2 H
stop' x) t- q5 R: Z' Q
]
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color+ G; q; e( n: }! V: d9 i. `
crt num-cars1 w/ _8 f; {1 t7 B2 {
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# q" j, n3 p8 L( Q setup-cars
% F2 o0 s' M" I; g4 p set-car-color5 j. Q4 Y2 e& e3 \% M
record-data- I, P% v; y; [
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% w z/ o9 n4 [& o0 Z7 p ;; give the turtles an initial speed
* R0 z* H" P/ l' K- ]7 `5 O ask turtles [ set-car-speed ]8 w/ l! `2 n2 n+ L7 o
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reset-ticks
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;; Initialize the global variables to appropriate values$ d9 z) }9 W0 @9 `, U% {
to setup-globals# v, T9 d7 n& F& @" t3 k6 i
set current-light nobody ;; just for now, since there are no lights yet" g9 w0 u" h8 P. k3 q) t* B
set phase 06 ]7 n9 D1 N* s- o3 M n7 `- _ ^
set num-cars-stopped 01 |2 J, E4 D2 J; R; D) r
set grid-x-inc world-width / grid-size-x
- N8 u/ U& ~$ G8 r& P5 o( }2 e set grid-y-inc world-height / grid-size-y+ |8 H# a3 s$ Y' @6 A K0 }
- W9 X: r! _0 x* q2 i- g8 } ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
9 y* ^( E4 Y' h* @) B1 f. n set acceleration 0.099% N* [( r( c; q+ \
end4 t) N6 i( ?& L& V! x* c
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,) P/ W( v8 k4 F% @/ [# r% P
;; and initialize the traffic lights to one setting
; A2 \( e& P6 L0 L% |6 I1 T2 b8 M: `) tto setup-patches
3 N; W3 y7 O/ ^& \6 E ;; initialize the patch-owned variables and color the patches to a base-color
& E* |1 x$ e9 ]/ g ask patches
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' i" {5 q y/ s* R set intersection? false; I7 Z" K& C8 X8 l: A
set auto? false, A1 }' I* v b* X2 d3 ]
set green-light-up? true3 u+ N1 j# I: n4 e- q' @* [
set my-row -1+ V2 A2 O! x6 j/ k7 Z
set my-column -14 }# q9 k9 n& Q! C6 }
set my-phase -1
9 s7 e5 U% m0 e6 I. R2 [ set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
/ B3 c" ^9 l5 r) X- `* ?1 h set roads patches with% G6 i: N! w5 H. O) X" {) l
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% C8 N+ h1 a2 X4 U8 J4 N, R
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 B3 R$ s, O F& x6 L: q! K4 M set intersections roads with8 e& X! L; R# x) A3 L# S
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and* X ?' }2 P6 p. Q4 }+ g" R
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 m/ n$ z* S! ]) F
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ask roads [ set pcolor white ]
8 X* L( ]8 J0 }4 X setup-intersections* ]+ ~5 M: z" O" n3 C/ A$ v
end
' _% c* P1 M$ j其中定义道路的句子,如下所示,是什么意思啊?
+ ]9 Q& E. x h8 Q" w7 ~ p- [ set roads patches with# A. @ h9 ^9 V2 L) `, |
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or, M0 P! S+ y1 H! I: H
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]' n* ?, F+ q+ z! F/ B! [$ F0 c/ u) E
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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