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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 d. T' l @) ]
netlogo自带的social science--traffic grid这一例子当中,+ G* Y5 V4 s" {2 P: P
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
. ~, Q: n9 t$ V5 R$ B grid-y-inc ;; the amount of patches in between two roads in the y direction
& D6 B' p6 }$ e4 A- I4 Q acceleration ;; the constant that controls how much a car speeds up or slows down by if& M6 F0 g2 K8 [% _9 a. o- E9 W
;; it is to accelerate or decelerate
' e+ Y6 ~6 G+ v$ t; Y& R phase ;; keeps track of the phase. M6 H' H: c9 y, l
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure5 I, L- W/ X! {% ]2 W1 L
current-light ;; the currently selected light4 {4 Q, w* I8 M6 U1 D2 Z
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;; patch agentsets8 i. ?7 J; v$ S5 n- |- z: H
intersections ;; agentset containing the patches that are intersections
# k8 Y, a4 N& K! k v roads ;; agentset containing the patches that are roads& b% R0 W) F5 D1 J u3 D t, Y
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turtles-own0 p, F/ [0 M- n) F2 d6 A6 T1 d
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speed ;; the speed of the turtle) L: b5 l% e% b5 @4 W5 v8 J/ T1 S
up-car? ;; true if the turtle moves downwards and false if it moves to the right
! [! ^( h7 E8 L4 G- E wait-time ;; the amount of time since the last time a turtle has moved# B$ I: l9 K% P: T4 n; t
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8 @9 X4 y9 e/ e8 Q! npatches-own
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intersection? ;; true if the patch is at the intersection of two roads
& A4 S. l5 s: H green-light-up? ;; true if the green light is above the intersection. otherwise, false.
" A: b+ \8 f. ?2 W- N% M ;; false for a non-intersection patches.
* s8 a5 I+ Y% ~2 s my-row ;; the row of the intersection counting from the upper left corner of the
4 O7 {/ @! p* ?, R6 L ;; world. -1 for non-intersection patches.4 P+ @( s& g, k% C* h
my-column ;; the column of the intersection counting from the upper left corner of the' `/ I. L9 Z: P% E7 F0 G2 G) U8 V
;; world. -1 for non-intersection patches.
/ r* J- P9 Y0 r+ T6 D9 e* T my-phase ;; the phase for the intersection. -1 for non-intersection patches.
6 V0 v8 b; e* N* m auto? ;; whether or not this intersection will switch automatically.% _: Z+ L* z2 k8 t; R9 T- G; c
;; false for non-intersection patches.
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' D" M9 U8 C5 `% e. j U# l;;;;;;;;;;;;;;;;;;;;;;
5 e& L3 _/ F2 a;; Setup Procedures ;;
6 w0 j2 y9 A( M; ]4 a;;;;;;;;;;;;;;;;;;;;;;
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0 G4 U9 \, q/ F. k/ U. O! a;; Initialize the display by giving the global and patch variables initial values.$ r0 o/ X5 ^4 L7 S
;; Create num-cars of turtles if there are enough road patches for one turtle to
2 U$ a" w" _5 O5 w;; be created per road patch. Set up the plots., u+ b4 r( t# u1 ^5 H
to setup6 }7 }7 S5 J/ Q( x, y
ca
u9 h1 d$ i7 h- X5 ?0 l$ h; _ setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
" D) K3 L8 P' u/ {3 G( r% [) Y* ^$ ` setup-patches
1 s! D j3 [# s$ J I make-current one-of intersections! c0 e6 O3 E/ h7 {. i& X* W3 n# C
label-current
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set-default-shape turtles "car"
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$ J; R1 I6 h% A1 T7 E6 h( u if (num-cars > count roads)4 W9 A( {, t' M9 s9 Y. d
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user-message (word "There are too many cars for the amount of "
; y/ F4 } G# v "road. Either increase the amount of roads "' o. ?4 J; ^5 X; y
"by increasing the GRID-SIZE-X or "8 {! I* l' w( H* t7 O% M0 ^
"GRID-SIZE-Y sliders, or decrease the "
0 g: Y0 c7 h) f6 Y2 |# p$ i! Z; z8 p "number of cars by lowering the NUMBER slider.\n"9 ]! Y3 o: U5 `$ ?8 v2 P. z$ X3 m
"The setup has stopped."): e$ A0 S9 y3 P+ p9 J4 }" V
stop: ^+ _% L4 X/ `6 H. P
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
3 Q+ j# T' C7 }, r- E# A crt num-cars2 s, f: e4 p8 n; D( p5 B2 j
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setup-cars
; D! @. y$ N3 Z0 P( B @8 a set-car-color
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;; give the turtles an initial speed
! V0 c7 l6 a% \' j5 x+ X ask turtles [ set-car-speed ]/ Z0 u% _4 D z$ W! w. |- \ f
! V8 T6 p8 M5 M6 x reset-ticks" \: {4 i3 k% @" O& f
end
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9 ~- _. K3 x* U8 i5 N3 P;; Initialize the global variables to appropriate values4 {" ?, @) y5 }/ a7 o6 I" }
to setup-globals
5 v9 @ u, G' a: H set current-light nobody ;; just for now, since there are no lights yet
/ j) I3 }. s5 }2 Z set phase 0% p$ [% \. J& y$ a; r2 @
set num-cars-stopped 0& u$ G) {& W, b
set grid-x-inc world-width / grid-size-x' I" L7 e7 j0 p" b# L, N, O Z/ C* w% v
set grid-y-inc world-height / grid-size-y- h8 |. j% z0 k1 p3 `+ ^
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
8 ?& P' Q% v- t L8 g \ set acceleration 0.099
& ~+ g _& T4 u; ] H$ Oend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,, d; X* ]. t* x8 y) f; o8 w( {' |
;; and initialize the traffic lights to one setting- b% v% h: }! D5 z4 W
to setup-patches" q) z9 x) R" ^5 S2 n
;; initialize the patch-owned variables and color the patches to a base-color
* v6 ~7 ^) l: ?' U ask patches
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/ [0 [/ u# `" S. U* i! J3 z R set intersection? false
, I t& W2 d" }5 |8 J set auto? false
) u3 N( z* K% `8 a8 Z9 c set green-light-up? true3 y/ R6 I9 S$ \/ X
set my-row -1. O- Y9 o; `9 }" \5 L0 L* @
set my-column -1
2 j9 r1 X5 f/ e4 c$ [ set my-phase -1- i" j2 u8 P5 M
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
! O7 v% W: v2 m0 X0 J& j" n set roads patches with t5 k3 Q' m. R0 N- o. E4 i
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or i k) d: O& z$ s3 f+ d' I
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 l7 i* ?' X5 q9 i set intersections roads with
$ ]8 c% o3 ^, c+ I& Y3 b6 u5 w [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and7 t3 [ P; p( _! D1 M
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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/ u. u& E: b M! D ask roads [ set pcolor white ]
9 H* J' c! D/ Q8 u7 p; m setup-intersections( c |, y. P1 @, d$ H, M; w
end% N( h3 S$ R5 u' j. c- p
其中定义道路的句子,如下所示,是什么意思啊?
) m' A& @( Q: C( k set roads patches with' w# P) y9 K* `7 O4 k) P+ b
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
* |- w7 G3 J2 {9 w0 m& ~) l$ Z4 w (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) {5 q2 R7 k% B. U" {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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