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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。+ K- \# o& J$ }1 W6 z/ ^5 c, n
netlogo自带的social science--traffic grid这一例子当中,7 [" i+ U7 M6 P; a
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction2 k' A7 ]1 n+ x
grid-y-inc ;; the amount of patches in between two roads in the y direction
+ f& A7 l9 d+ v( v* L acceleration ;; the constant that controls how much a car speeds up or slows down by if( B& Z n* h2 C8 Q" [/ [
;; it is to accelerate or decelerate5 Q5 n7 @( _6 _/ w' \3 l
phase ;; keeps track of the phase* \1 ^9 l& S6 [' D* h0 c
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure# o' D7 R6 [ d2 X' I h4 T- a
current-light ;; the currently selected light: Y2 z B& G p" `1 _4 [8 ?: O0 ^
0 @* v* y, J! ?! m+ b0 _9 j# ^5 ^ ;; patch agentsets+ }/ A7 }, w7 y. Y1 w
intersections ;; agentset containing the patches that are intersections7 h& O0 r. j1 T; b/ P
roads ;; agentset containing the patches that are roads
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turtles-own) b" Z: z/ H+ n
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speed ;; the speed of the turtle
^. ^* [7 ]+ R! p6 s7 y( ?+ N up-car? ;; true if the turtle moves downwards and false if it moves to the right
& C6 J; s3 P+ U4 h& C) L0 o' M wait-time ;; the amount of time since the last time a turtle has moved& k/ B: ~/ K8 G
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patches-own/ o+ ?# X( ?3 c; K' v4 r: b5 e$ G
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intersection? ;; true if the patch is at the intersection of two roads) B9 B- L# v) y) v! |
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
/ v6 T0 z' \' I5 l, F4 B4 S1 K ;; false for a non-intersection patches." ]+ i7 g% o5 w4 N2 ]
my-row ;; the row of the intersection counting from the upper left corner of the+ ], N% C2 n1 @% a" [
;; world. -1 for non-intersection patches.
( H; h7 ^# @& Q3 n* A7 _ my-column ;; the column of the intersection counting from the upper left corner of the! \* |4 J4 C2 J! I$ J
;; world. -1 for non-intersection patches.4 u7 {* z" \3 U' [, Y* O
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
, m1 l" W% p P auto? ;; whether or not this intersection will switch automatically.
# H5 F: t' z+ f9 U. n0 | ;; false for non-intersection patches.
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t+ Y1 z$ U5 X% x S& y' L;;;;;;;;;;;;;;;;;;;;;;
) O* G: n( d' \" Y# d;; Setup Procedures ;;
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; z7 a2 T$ c# R) X8 H) a( [. ~: j;; Initialize the display by giving the global and patch variables initial values.$ {! O3 A# `8 _
;; Create num-cars of turtles if there are enough road patches for one turtle to
) G" K: i& a! t0 Z+ _0 v6 T- p;; be created per road patch. Set up the plots.* ^$ c# N6 o# h E* T6 Y0 Z. f
to setup
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" e1 {& ~9 I+ ?9 G setup-globals- v9 g4 ~$ T6 I$ G* }
! @$ {9 M2 I1 w8 l( D" ]" n ;; First we ask the patches to draw themselves and set up a few variables/ i; k) M& v# D6 }$ L
setup-patches
0 b+ f1 Q& t& \) r0 u: D make-current one-of intersections
+ i3 F$ X* v+ \8 E label-current
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/ W0 I( d1 r& G set-default-shape turtles "car"
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c) Y( [# I+ n. `" N if (num-cars > count roads): J) B9 x3 H" c& K# a, O5 M2 `
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user-message (word "There are too many cars for the amount of "
* \. [3 w6 _6 g2 O, L* J6 X$ ~ "road. Either increase the amount of roads "% d+ F! f" z& A* k$ I% \: V
"by increasing the GRID-SIZE-X or "& `( c' @7 B0 s6 x: z
"GRID-SIZE-Y sliders, or decrease the ", @( k# O# X) Z+ V% ?8 v! K) Z
"number of cars by lowering the NUMBER slider.\n"! q% o5 |) f# i0 N7 M
"The setup has stopped.")3 P# v: v) f' I8 v* _
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color2 x% ^; Z6 K* e, V# F
crt num-cars
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1 H" F& ~0 z6 B- d8 V8 R+ _4 @: K setup-cars
, ^8 ^6 W1 T0 g4 ?5 y set-car-color
! a; Z; B" @' k" h" n, C* c+ {5 N5 R record-data
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;; give the turtles an initial speed
9 p) l% e! L' _/ l ask turtles [ set-car-speed ]
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`' i4 r5 \1 Z6 Q' K% u reset-ticks/ m2 {5 Z/ h3 F4 _" \1 V) Q: a! z. ~
end
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;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
! D( g, t3 w) n* S$ \# _ set phase 0' b$ }; m& \0 x
set num-cars-stopped 0/ J2 A0 i p4 c: E) ^
set grid-x-inc world-width / grid-size-x
* E7 t/ \8 ~8 [, Z) e2 p# H1 x( U set grid-y-inc world-height / grid-size-y7 R; ^1 ?- [6 q" w* }# n. p
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
$ F% S3 k- d. i! Z% j, b0 O set acceleration 0.099* B" K3 E0 }7 I- B
end
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: k5 H6 [4 Q% V1 m% q. X;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
5 v( E# u: N P5 ]1 p& Q" t8 Q;; and initialize the traffic lights to one setting
# c4 M$ g6 D5 a+ @/ Lto setup-patches# |& c9 K- x+ W' }5 P' R
;; initialize the patch-owned variables and color the patches to a base-color
, ]4 q! z9 j/ i) o ask patches
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! a1 H) v( G1 X: f set intersection? false
& K8 D, w2 s# V! o* G set auto? false
+ {0 r8 x+ J" g$ t0 q set green-light-up? true
& P# }" R: }& r* J! @ set my-row -1
' W2 ?# A) A8 p/ b7 [ set my-column -17 O0 X; s! z3 k, {5 C. Y
set my-phase -1
1 E5 @7 O/ p& [ V+ a& d/ W" ~) Y set pcolor brown + 3- ?6 g2 e9 Y' L) I/ H# T; M. I3 d
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* j; S+ C; B3 R e ;; initialize the global variables that hold patch agentsets
s& M* S$ |4 p& i. q set roads patches with: r) p$ U+ S/ R
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
$ A4 Y* K& n% c: q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 G- w6 G G& ~( j
set intersections roads with
4 A- E& I: X/ _4 K3 `9 H4 j [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and8 _) M& u: X' z# M9 O# F
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]" D5 m8 e8 U9 W1 I
setup-intersections
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; k, t9 _+ _9 i" d( Z其中定义道路的句子,如下所示,是什么意思啊?- Z* k- l5 o/ f' U: u
set roads patches with; X4 A2 {3 H7 y
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 Z* f4 N% D! Z2 {. ]6 L (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: Q! L) o# J7 j2 H6 D. h6 o+ ^; \' X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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