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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。
* V1 _3 r5 G& p9 wnetlogo自带的social science--traffic grid这一例子当中,
* Y5 q$ U( }, v, w: kglobals4 ^: G: t% j6 l' L8 u4 D: ]
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grid-x-inc ;; the amount of patches in between two roads in the x direction
! v: u- \4 l- V2 J$ D! s, k grid-y-inc ;; the amount of patches in between two roads in the y direction9 Y: z" h0 ^. M# l: o) Y
acceleration ;; the constant that controls how much a car speeds up or slows down by if# t; k2 f, }1 Q0 k
;; it is to accelerate or decelerate$ Q$ j& E) S; E# K- x7 g
phase ;; keeps track of the phase
3 x7 ^# m+ E0 |9 [7 U num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure& y$ v5 Z. Q- h6 ^
current-light ;; the currently selected light. B9 d3 ?0 d3 s/ m/ |7 u
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;; patch agentsets% G% b" Z% n( L& c. ?
intersections ;; agentset containing the patches that are intersections
& \7 ~( i& w g roads ;; agentset containing the patches that are roads0 c2 @; ^& {; i# R' m) o& Y- f" j
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turtles-own
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0 ]* J- S3 a' R speed ;; the speed of the turtle
# C/ i T" Q7 g3 v1 i4 i up-car? ;; true if the turtle moves downwards and false if it moves to the right
$ v7 }. ]2 O" o" m+ S3 w- g$ Q wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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2 m! G+ ]2 k9 T1 O2 ? intersection? ;; true if the patch is at the intersection of two roads+ }$ Q7 d6 S3 ^: @: l: V
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
, a4 A8 M" Q8 l ;; false for a non-intersection patches.
. U& L6 k3 ~+ O2 D3 r! w+ I my-row ;; the row of the intersection counting from the upper left corner of the
) p7 d9 G0 z$ ~- }& N4 [, G ;; world. -1 for non-intersection patches.
% E* }& c8 Z1 E: @6 w7 P9 g) L my-column ;; the column of the intersection counting from the upper left corner of the
) ^( V: p3 V) s1 E ;; world. -1 for non-intersection patches.
6 k1 ?/ @$ _1 @4 ^ my-phase ;; the phase for the intersection. -1 for non-intersection patches.
( t1 x( O4 S+ C. q& X, E' y auto? ;; whether or not this intersection will switch automatically.
. Y) v4 @% w8 N! q2 H ;; false for non-intersection patches.
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# I' ]% S$ }5 @/ e;;;;;;;;;;;;;;;;;;;;;;
" c7 E- V& p+ c8 d- C' L, z' U;; Setup Procedures ;;
2 |) `; ?6 M3 [# `9 H' e0 v;;;;;;;;;;;;;;;;;;;;;;4 t# T6 k2 _! E
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;; Initialize the display by giving the global and patch variables initial values.
6 F7 a8 G% `( s; M: P: d# z0 y;; Create num-cars of turtles if there are enough road patches for one turtle to! V- U9 e* V! A( O& `
;; be created per road patch. Set up the plots.3 _( E( y1 e7 S" ?) M
to setup( Q: x2 X' U* D! j
ca
8 e9 p2 X5 z+ R; s0 y2 z setup-globals2 B8 M* T" z7 |: u* w4 \* |+ ?" I' C
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;; First we ask the patches to draw themselves and set up a few variables
: o+ Z: @: j) ]2 j$ P5 F( } setup-patches
# K: y. E3 v$ n" _- i make-current one-of intersections t5 ^# m( q( e( j: ~' B; w9 J
label-current
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set-default-shape turtles "car"5 w1 a: ^+ R5 a9 o5 p- E7 T
1 n, J/ A5 L( o4 ~' Z0 X* G9 d2 {. O if (num-cars > count roads)1 X" ~7 x1 r4 E
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user-message (word "There are too many cars for the amount of "
4 ]/ V4 I" p2 {/ k* P "road. Either increase the amount of roads "
: u( f( n5 [, ^9 l+ f "by increasing the GRID-SIZE-X or "$ [$ W# E: U! _: `% g6 d
"GRID-SIZE-Y sliders, or decrease the "
( }1 k/ b9 x) \" ~' `2 W "number of cars by lowering the NUMBER slider.\n": D+ E4 W% |2 E7 x% R( _. F0 P5 p
"The setup has stopped.")8 D( y9 t4 B4 `8 o
stop
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7 t. T1 n3 f& l0 \ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
' l9 O* x# c6 U- s2 ^% \) x7 o crt num-cars
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9 |7 y2 I1 `8 g. q: _+ K setup-cars0 P8 ~: F# R4 a
set-car-color
5 `! I( Y1 b' Q0 I( ] E record-data
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% Z5 ^ o. w- s: e6 t1 i3 m ;; give the turtles an initial speed
' y9 T F9 \( ^$ f ask turtles [ set-car-speed ]
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reset-ticks
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8 \5 ?* f2 V$ z- |;; Initialize the global variables to appropriate values% _% b! D5 `* p2 H1 U/ ~" @' @
to setup-globals
& N5 N9 k* c. T) Z3 e set current-light nobody ;; just for now, since there are no lights yet
4 \" x' N* h) U7 ? set phase 0 `0 M/ f8 E! U; K! K1 \
set num-cars-stopped 0
8 w6 Y3 N+ Y3 x set grid-x-inc world-width / grid-size-x
3 X& I! E. }! D5 y% I( A/ R set grid-y-inc world-height / grid-size-y
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; h% ]6 b+ q+ w- Y% } ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
; S3 d+ {" V' Y' t8 u% ~& |: o$ L set acceleration 0.099
1 p D& S: h; i% J( B# @end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,5 z- N1 a c$ ~8 k3 J9 k! H
;; and initialize the traffic lights to one setting
" g% [/ z7 ^. }& ~' {; h; @to setup-patches
( M/ f; y. d$ B( N3 [ ;; initialize the patch-owned variables and color the patches to a base-color
( Y6 N- @5 Z. |( Y' w+ _: L ask patches
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set intersection? false
# L1 ]# q+ ~3 i- G- n7 \" @ set auto? false4 [/ {5 J8 L% S6 z
set green-light-up? true- T2 R1 d3 G o/ A! [
set my-row -1, C1 I: U7 `" m
set my-column -1
4 X' X/ o# T1 [% e& { set my-phase -1
4 n: H& J) B( y/ e set pcolor brown + 3, \5 f+ l8 w$ v" c) y/ }: N
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3 [4 a' @) Q- _; w( R ;; initialize the global variables that hold patch agentsets7 d2 Z1 f) ^1 }. |8 A: s$ Y: d/ E; X
set roads patches with
q3 G1 r! F' P6 ^. ^# | [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 b& y+ Y1 n6 J9 q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
4 s; D# ?) O3 P: S: J set intersections roads with- A% [6 e# I3 }- G$ n; W$ p
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and9 @. U" N, r1 E
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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3 t, _: o8 o, l ask roads [ set pcolor white ]
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其中定义道路的句子,如下所示,是什么意思啊?
& [6 i$ F! l7 ~8 q5 N, m& m& h set roads patches with8 a9 ?7 S( P2 Q! k. W' n9 I
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
[4 O2 L% z! z% M (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
Q% [# r: ]6 E) t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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