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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, Y. p3 c: d8 H) ?9 p7 a
netlogo自带的social science--traffic grid这一例子当中,; `) K! V" a5 U) c6 s! m; k
globals5 O. K! p8 Z3 i4 `% |: W" A* t! P0 F: ~
[
, q/ O" e& \: q# x e" p* q grid-x-inc ;; the amount of patches in between two roads in the x direction8 U8 ]% ? m6 G1 Q- v
grid-y-inc ;; the amount of patches in between two roads in the y direction
& l% k) E* q( r- e# v acceleration ;; the constant that controls how much a car speeds up or slows down by if' V3 Q& e# ~ e6 j
;; it is to accelerate or decelerate# I$ Q2 i8 ^ H2 Z4 f9 D
phase ;; keeps track of the phase# d& k, U. ` |! _
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure: M8 j! y/ U F- g
current-light ;; the currently selected light* [, j: i) M* K3 ?( O# s* n- V
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;; patch agentsets
' H/ ?+ r$ r7 O4 G8 V intersections ;; agentset containing the patches that are intersections
- F q9 k8 `" H! e; e roads ;; agentset containing the patches that are roads9 k0 X a$ M* o* ~
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4 G0 y! m# f; W' _* i# bturtles-own
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2 T7 U" T& E9 y0 r speed ;; the speed of the turtle
3 |$ o" J# y9 Z5 s up-car? ;; true if the turtle moves downwards and false if it moves to the right
O2 P4 `2 C. r" p wait-time ;; the amount of time since the last time a turtle has moved
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2 H( G" {! ~, K1 ?: L( Qpatches-own3 W: y! ~) g# q8 k. r; O' O
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intersection? ;; true if the patch is at the intersection of two roads
. @7 R4 J3 @9 D/ n7 V; ?% I: _ green-light-up? ;; true if the green light is above the intersection. otherwise, false.4 w( |1 P# M! b+ C+ F
;; false for a non-intersection patches.
$ g$ e; v3 x" u2 e8 V8 M, E# a$ q my-row ;; the row of the intersection counting from the upper left corner of the5 Q; @: v" Z+ _4 o3 l
;; world. -1 for non-intersection patches.. ~& ^' v$ a; w
my-column ;; the column of the intersection counting from the upper left corner of the
2 s& p9 I6 d, n2 g9 ^9 | ;; world. -1 for non-intersection patches.8 b6 F/ e; v7 t
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
, W A- L9 n3 ?6 g! I2 a auto? ;; whether or not this intersection will switch automatically.6 n( H* h. q0 e, @0 V; ]
;; false for non-intersection patches.
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( `6 Y) v7 O( O;;;;;;;;;;;;;;;;;;;;;;; ^& |7 ?) [# [7 J) Q1 \
;; Setup Procedures ;;
, o: n. h& R; C;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
! I7 M% [: d6 l3 a+ |3 W' }4 F;; Create num-cars of turtles if there are enough road patches for one turtle to
, o( v) Q! H# W' k& x9 R;; be created per road patch. Set up the plots.
* A' K4 g& a/ Kto setup' E# C9 @/ {& m2 j
ca
8 g( X- n* A+ o4 F/ f& W setup-globals& w9 K' [. a: B# m
( b8 O+ x6 Q. _8 g ;; First we ask the patches to draw themselves and set up a few variables
3 c+ b3 e% c2 j8 { setup-patches
6 Y" k( j" {3 T. { w* _4 I# e! ~ make-current one-of intersections
8 J; A" \' ?/ I/ u: T label-current& s- G6 Y% X( g) K/ p! J [: u
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set-default-shape turtles "car"- p, V7 T7 P7 U" A k M9 p1 E0 s
8 e# C& d' f2 z/ c if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
: P" o$ _: p+ g* w! e* e1 O "road. Either increase the amount of roads ": G6 \" i$ h0 \# B: Z! w/ u [
"by increasing the GRID-SIZE-X or "9 Y) `. q2 j3 j
"GRID-SIZE-Y sliders, or decrease the "4 L2 Q3 J1 ]1 y9 P1 m1 ^+ j3 \) ^
"number of cars by lowering the NUMBER slider.\n"
, Q# G6 m- k3 Y! W/ j# N6 I "The setup has stopped.")
: ]% j" q$ ?- P stop0 M2 q, {0 J3 T& V) v% ~2 T9 w
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; j0 n6 p9 ~; [4 M! b ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
( i ~) Z0 |8 N) K a2 L% X crt num-cars, Q; Y! h8 A2 ?
[
, H7 e% L, A* n3 n' }/ |+ Z setup-cars Q1 P% g; r, U; k1 n
set-car-color$ T7 M9 @( T9 Q) R
record-data
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; z V& c% U% U" Q" n1 i0 ] ;; give the turtles an initial speed
2 ?( }7 @. g9 t0 P" K; L( F ask turtles [ set-car-speed ]
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7 |1 A% }/ X& \: w reset-ticks
! B A! q7 `/ {; }( Nend
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;; Initialize the global variables to appropriate values
) K# h( v' g8 ^$ D$ x6 Yto setup-globals
& ? ~/ J& j7 p7 u) n3 G: z set current-light nobody ;; just for now, since there are no lights yet
1 A% h/ P6 v& C3 M0 [" X! I set phase 0/ I7 e9 I; P8 {
set num-cars-stopped 0
5 X r: O6 P/ q* n: ~, b set grid-x-inc world-width / grid-size-x
7 F' n, |+ j9 D: k set grid-y-inc world-height / grid-size-y
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7 T% L2 b! @, j. w+ e$ H ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
! T4 x( ^8 H6 T: P f8 w set acceleration 0.0992 ~4 A0 |7 h6 ^, j8 G5 P, s6 ~4 u# g
end
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% t% P* @: s8 R; J- M# `;; Make the patches have appropriate colors, set up the roads and intersections agentsets," F$ B# }+ R% M% L5 }2 D. X# B
;; and initialize the traffic lights to one setting1 _' R, _5 L" O" x2 D1 L( P8 a
to setup-patches
& x* z& W) {/ @; f) T; z' ]& V2 r ;; initialize the patch-owned variables and color the patches to a base-color" c! M7 M: V7 [" D% t# `9 \2 u
ask patches
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set intersection? false/ h3 h( a0 I8 b/ l5 ]1 W1 r
set auto? false- S$ F2 \5 F' q3 j
set green-light-up? true# M, b4 {. L4 F% b& r8 L' }# I
set my-row -1- X8 |2 j+ N0 P7 v9 ~5 ]; y
set my-column -1
5 T+ h4 l7 n: n. b1 c set my-phase -1
; X7 I2 b& T( _6 L2 n8 S5 U set pcolor brown + 3" D2 e( ?- Q1 B. j) P% l+ ^" Z
]
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;; initialize the global variables that hold patch agentsets' H4 v# X4 Z& r' X& W
set roads patches with
- N9 |/ ]/ \1 D: c& a$ n* G; K [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
. y- C6 M/ T0 [0 z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 x" \: g5 d6 n
set intersections roads with1 N5 b6 L3 B% w3 d3 N, K
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and# b1 I& ^# N, u" U! e% d, u
(floor((pycor + max-pycor) mod grid-y-inc) = 0)], i, M4 o* I; _$ M! E3 B, k
8 p+ d \* ?8 @/ V ask roads [ set pcolor white ]" _4 p- m/ s. l: D% L- i
setup-intersections
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$ C. w' h/ R" h其中定义道路的句子,如下所示,是什么意思啊?
" C0 |- r# v4 u8 f set roads patches with5 h; ?( d( [: h, H7 u8 I4 g
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 C- Q. B# \1 c: n& P5 e5 j1 y; X/ p
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 ?( J, C* T3 A* t; ` Q. J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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