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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。. y! N% e! J' Q
netlogo自带的social science--traffic grid这一例子当中,, Z" O" ]. B) P) I3 c. N
globals+ ]; u. _% A2 l, L4 L9 G$ z
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1 I6 I* z# \! Q% d Y8 t* l- q# q. W grid-x-inc ;; the amount of patches in between two roads in the x direction
" u! T5 Y# h% g4 R" ? grid-y-inc ;; the amount of patches in between two roads in the y direction
! a1 ?6 h+ j/ H: s) y- ?- Z/ H9 c acceleration ;; the constant that controls how much a car speeds up or slows down by if) h0 p/ s [& ~8 U6 o
;; it is to accelerate or decelerate7 W$ ?, K3 L: ^
phase ;; keeps track of the phase' r& Y- E$ X- d3 G
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure" r9 ^/ c9 m/ v5 Y
current-light ;; the currently selected light
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;; patch agentsets
; n4 L( x. W, a' j0 E. y) p intersections ;; agentset containing the patches that are intersections
7 ~7 b9 x9 }0 g- A( s. z roads ;; agentset containing the patches that are roads8 k: l& C# `5 o4 ?* X- S
]7 O5 I/ _& C% D8 k6 ]
5 J+ b9 O' c6 }1 gturtles-own& T+ }4 n- A, C6 ~2 r( ]
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: R, S$ o( ~) O) v ?& Q speed ;; the speed of the turtle
5 m' v _+ r' x# [0 ^5 m' R up-car? ;; true if the turtle moves downwards and false if it moves to the right
4 I: Y$ J: b: I/ E5 ?3 L7 {: Q wait-time ;; the amount of time since the last time a turtle has moved- o- |/ a6 ?" H6 e- K2 n$ s/ P
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patches-own" G$ @" ?+ G7 r+ X; l! {7 D" r
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intersection? ;; true if the patch is at the intersection of two roads& w6 a3 _" x2 P+ j
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
1 k3 Q9 x \1 f: p% A ;; false for a non-intersection patches.
+ m- A2 q% o, }' x. Y my-row ;; the row of the intersection counting from the upper left corner of the$ n, G7 x; K9 i; G Y1 ^) T
;; world. -1 for non-intersection patches.
" M* t a$ U+ C% M; @ my-column ;; the column of the intersection counting from the upper left corner of the
# }4 T! G, i2 u5 V9 I& Z ;; world. -1 for non-intersection patches.8 M# j* \* v( F! Z1 ]6 ~
my-phase ;; the phase for the intersection. -1 for non-intersection patches.4 x9 e, k- q3 D4 Z1 w7 n
auto? ;; whether or not this intersection will switch automatically." L5 ^. f; @5 b& ]8 v+ o
;; false for non-intersection patches.
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3 w- x* J% p, M3 ^2 b;;;;;;;;;;;;;;;;;;;;;;
2 T" r( {1 {3 Q# m+ ?;; Setup Procedures ;;
& R# G0 D( z- o% H& b;;;;;;;;;;;;;;;;;;;;;;
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9 Z; D7 Z3 W9 J4 E7 N' j4 v" U;; Initialize the display by giving the global and patch variables initial values.5 o6 K) ~. \$ A; r
;; Create num-cars of turtles if there are enough road patches for one turtle to
, W- I. m {- l6 F* r2 s: Q' g3 h;; be created per road patch. Set up the plots.
! m4 i! Q8 R/ hto setup4 N/ Z6 ^3 m% M# z
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setup-globals' S4 T7 i! z- V" U, ?9 o" V9 K
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;; First we ask the patches to draw themselves and set up a few variables" d7 u [1 M( ?( ^# `
setup-patches
5 V! M; D$ _2 z! |8 q; A2 H; m3 P make-current one-of intersections
' c) [. u) o" {4 w' i6 m label-current! Z {& J* [1 e2 D! ~6 V1 @3 F
! S8 o2 w; R1 Q+ _0 K' ` set-default-shape turtles "car"
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if (num-cars > count roads): L' v$ I; N, n
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user-message (word "There are too many cars for the amount of "
: f3 m% g# H+ s& u/ a4 Q "road. Either increase the amount of roads "6 n% W, B, e( j/ K
"by increasing the GRID-SIZE-X or "
" e, C0 ?3 _ W# \: w "GRID-SIZE-Y sliders, or decrease the "! j' l. u+ H$ a
"number of cars by lowering the NUMBER slider.\n"1 Y1 t+ Q- Q0 R
"The setup has stopped.")5 f5 _/ ^* B) t# D, z1 \$ F* i
stop
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5 r! _; A |# l$ F7 ^ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
! u+ p; e5 {3 y' ~" W: \8 p crt num-cars) U( g. e2 T3 `3 c) X) H! k4 L: S
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6 r& Y" @- R% [9 S1 U setup-cars
" ^' F. W; h; v/ w4 G$ ]- |4 H# R set-car-color& l! R7 K9 Y1 I. P1 K
record-data. @' ]) [* |4 x0 k. b
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;; give the turtles an initial speed
* X& k7 I; |1 I1 I. S$ u% ^ ask turtles [ set-car-speed ]
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reset-ticks
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) f0 c; L& R7 ?4 |: F5 m- {;; Initialize the global variables to appropriate values, U, r+ q: J$ K* f/ `( l8 o
to setup-globals6 ?/ ~) D1 [% _
set current-light nobody ;; just for now, since there are no lights yet6 u9 |/ `3 x. ^6 S" e+ \% d
set phase 0- N8 o% X" B( x' O! L- J
set num-cars-stopped 0
: O/ r: G* A" ?6 }, J set grid-x-inc world-width / grid-size-x
' ?) J' ^2 Y, N8 S set grid-y-inc world-height / grid-size-y. u/ w7 v) E1 ?1 \: a
9 m* H9 G$ P7 Y3 c8 H- \! I9 a ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
! h8 B9 W# I( ^- b7 p set acceleration 0.099
J; ~1 `, t+ z+ fend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
& q" b# z6 U7 N* a) x;; and initialize the traffic lights to one setting
% N H( O' A& C% k+ S7 I4 jto setup-patches
( }, w* S# ?, p" g0 i: K/ B. ^- M ;; initialize the patch-owned variables and color the patches to a base-color$ ?& B2 [/ e& \+ G: [/ c$ r. C
ask patches y2 M. a% q* P
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( |& r) M$ Y% n' {. X set intersection? false
# L% p3 D# Q/ B0 y3 I! n set auto? false1 L* K2 H- [- E U S9 k
set green-light-up? true& V. f/ h, Y/ c( `+ H, P' K
set my-row -1) }- D) p2 f' r1 [% {7 |
set my-column -1
! { x' w/ W, o3 _# t set my-phase -1* P' f, e( f. v1 r. t
set pcolor brown + 3
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0 h. r- D" p8 a; c9 Q ;; initialize the global variables that hold patch agentsets
! G _/ A1 H; f set roads patches with
9 W% G0 M" z# ?( f# h [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" ~* n) @6 O" R# e. B& o) ]# I (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
5 B% Q( I$ h0 L set intersections roads with) Z; R% H0 y s# V1 {
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and7 q2 y& [) S/ b3 H
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 U& E( c6 e P$ f
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ask roads [ set pcolor white ]2 K V$ z1 @7 _) Q8 v7 k) S
setup-intersections$ I7 t# C( b3 E# M8 y% S, j
end
, y F- R; b9 `- Z" q4 r$ p: |& C2 c其中定义道路的句子,如下所示,是什么意思啊?
2 W, Y" Q- ] X* _ set roads patches with" Y7 v1 S& f$ D
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
3 B1 R! b0 a& s; R/ h" C: D (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
# o- M% I! G% P' \4 d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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