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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。
8 V& l2 V4 c+ ?8 Wnetlogo自带的social science--traffic grid这一例子当中,
4 V) |! H d. Y9 V) B+ R; Uglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction# J% Q" T# ~7 J: R3 F
grid-y-inc ;; the amount of patches in between two roads in the y direction
1 w I/ w+ T* r2 O acceleration ;; the constant that controls how much a car speeds up or slows down by if6 V) l9 E2 ^: G5 f: H3 S# }
;; it is to accelerate or decelerate
) O$ Q+ \3 P& p! Z0 o5 G phase ;; keeps track of the phase1 ~7 D; e) W) N* x1 j
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure' }# x3 v* Y( m8 A1 g( n
current-light ;; the currently selected light
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6 {' b1 X6 V9 _1 I8 ]' v, M% x" d ;; patch agentsets; U& y% i* z% T+ `+ E2 }8 B) z5 y) ~! ^
intersections ;; agentset containing the patches that are intersections4 ~/ Q$ s7 S3 ^: a
roads ;; agentset containing the patches that are roads
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, v- F( ] ]& p5 l4 _( yturtles-own
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speed ;; the speed of the turtle
) E. G+ P1 ?9 V: V K* b {: Q2 x6 } up-car? ;; true if the turtle moves downwards and false if it moves to the right
, H) z: {) |: u8 z& i wait-time ;; the amount of time since the last time a turtle has moved
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& o/ X- `; J1 G7 apatches-own( Q+ K- a3 l2 X, a1 x# N2 z. R% Q
[
+ B' p; F' n' Y intersection? ;; true if the patch is at the intersection of two roads
- E' N- C0 b5 D) v# D& `9 W1 Q8 a green-light-up? ;; true if the green light is above the intersection. otherwise, false.' K' G8 {% H. ~# ]) r' O
;; false for a non-intersection patches.
6 H1 m/ \( ^) i6 u0 a, @5 b N my-row ;; the row of the intersection counting from the upper left corner of the
3 y+ S9 R* ^$ _2 c5 _ ;; world. -1 for non-intersection patches.
$ s" @' b8 ~2 c my-column ;; the column of the intersection counting from the upper left corner of the
$ N! K4 v w: Y ;; world. -1 for non-intersection patches.
: @( V5 d, b) o8 F) H5 g5 x& i my-phase ;; the phase for the intersection. -1 for non-intersection patches.) E- F6 s9 c( w
auto? ;; whether or not this intersection will switch automatically.
: { s9 b0 L( z7 J6 ~( r. C ;; false for non-intersection patches.9 e w7 u" L6 j: ]: q
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9 O+ u: x2 e+ i$ };;;;;;;;;;;;;;;;;;;;;;
9 p, D- T- T# g: q W. _! J1 D;; Setup Procedures ;;
9 t* i4 y3 |2 s( o& W8 h9 J2 o! T;;;;;;;;;;;;;;;;;;;;;;0 p% G o- H' n' x" p- N
0 \9 ?8 i2 U2 B4 V- ];; Initialize the display by giving the global and patch variables initial values.4 U8 U2 E% B. ]6 i, |4 d- ?' G' u2 A
;; Create num-cars of turtles if there are enough road patches for one turtle to4 C- n$ m) M) A% ?4 J3 ~
;; be created per road patch. Set up the plots.
4 i8 ~& h3 b1 O! x$ ~' C& Lto setup
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setup-globals% C2 F5 b* {. j% l4 s
& z$ C0 ]4 H6 ^; s ;; First we ask the patches to draw themselves and set up a few variables% u3 A2 D4 B6 X; Q1 N! `
setup-patches
_ a! W; R W. y% w make-current one-of intersections% m. U" z) R( w( j: Z* H
label-current0 _5 Z& [. j& V! I
$ f _9 r5 I7 W set-default-shape turtles "car"; O$ F9 q4 b# W
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if (num-cars > count roads)
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( P9 C8 s3 q, v, i user-message (word "There are too many cars for the amount of "
& m9 H' J) _6 L1 ~9 O "road. Either increase the amount of roads "# Z2 C5 \# l! k! u
"by increasing the GRID-SIZE-X or "; Y0 b% J- d+ L- n. e
"GRID-SIZE-Y sliders, or decrease the "( c" I9 u7 O; w0 ~, T
"number of cars by lowering the NUMBER slider.\n"
! {/ q: g* t4 d- u "The setup has stopped.")
A% W( e1 F6 L( s' R stop
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P% }/ N$ j* @3 Y. B, v; d# w( k; } ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color& s6 v. a4 o. Q+ q
crt num-cars
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setup-cars$ `; X6 E. N0 F0 G
set-car-color
2 T8 T. _4 ?5 n8 Q record-data1 o* Z) J& w+ x/ R: |5 y2 R0 l, Z
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0 t& P4 \3 g$ @3 ?' ~" x ;; give the turtles an initial speed
. N* T$ |1 a% I- a& V0 l0 Y/ H! Y$ N ask turtles [ set-car-speed ]- }/ i5 Q' O' q6 }
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reset-ticks
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o' X/ l& p9 ]3 D9 l;; Initialize the global variables to appropriate values. e2 h0 _; H0 c8 m0 a
to setup-globals
& M! w: B* [- X) ?4 K5 C, V set current-light nobody ;; just for now, since there are no lights yet
9 G) y/ o# w J set phase 0
4 Q1 ]9 ]& G' W* a: ]( b& o4 Q set num-cars-stopped 0$ o6 T# W5 Y1 q' c
set grid-x-inc world-width / grid-size-x
# E$ A0 ]5 K6 ]+ F: [0 O, ~* C set grid-y-inc world-height / grid-size-y2 n# i' n: |% i- k3 ~' D/ [
. W h1 b: P' m1 v ] ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
9 w, s! \* f& b. R" { set acceleration 0.0990 C. l# e4 X8 h4 ^, p' }) @
end
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. u( [/ }7 Z9 ^# E/ b;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
! r. E, Z* q8 U5 t;; and initialize the traffic lights to one setting" K0 z, i+ ^ M* N% h1 c& L
to setup-patches
- o; _3 A. v7 Z. {* Y' f ;; initialize the patch-owned variables and color the patches to a base-color
2 B, z, H5 x6 [' r; O ask patches
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# y E6 S* w4 C2 ?7 K set intersection? false
3 x$ c! J7 d( t9 \* G set auto? false; `; f4 o, A+ E# A
set green-light-up? true) w3 I! q7 R# C
set my-row -1
+ ]$ N4 E9 B& y2 v! ^4 W set my-column -1
u+ p8 Z0 T; V1 T, M set my-phase -1
2 n! U. N6 I/ @; Y2 r set pcolor brown + 3/ @' m+ ^% H% M8 G, S9 }' G7 p" I
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" |. n1 a2 h7 r. q& I: Y ;; initialize the global variables that hold patch agentsets
) x2 F! A4 ~" M) ?* P! E5 i2 J set roads patches with: R" U- i8 P# m8 G) y, ^
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or+ ]3 g" I! g1 S* t. ^/ x6 o+ r
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
5 w+ N8 q) n3 T" V6 _5 S; P set intersections roads with
( z, p+ m# U1 E5 q9 d" G# O9 F [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
; g1 ]. l0 e) Q& Z: v (floor((pycor + max-pycor) mod grid-y-inc) = 0)]; E9 E4 O( O# z- G* z E2 E+ J
1 [% l8 t8 v% s6 F ask roads [ set pcolor white ]# R6 S! [& C7 H+ s+ p; K7 X
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?
& X7 R! @( H6 i! L! \! f set roads patches with x; u, ^/ T/ u7 \7 a
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 [8 Q( h+ ~5 ]: J. l+ ] (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
" g! Z9 I3 A7 x3 y; b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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