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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。
. L- J7 q, Q4 Y5 Q% v0 fnetlogo自带的social science--traffic grid这一例子当中,2 h1 i+ y0 N$ R; c
globals
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6 P' _/ T6 j+ h+ r ^2 M+ K( y3 I* e, N0 P4 { grid-x-inc ;; the amount of patches in between two roads in the x direction" w# _9 k& K: \" s
grid-y-inc ;; the amount of patches in between two roads in the y direction
. f" @; c( p' \" Q acceleration ;; the constant that controls how much a car speeds up or slows down by if4 {4 K6 U8 W. `) { S) g" ?
;; it is to accelerate or decelerate
! \9 P1 x/ H+ n% K phase ;; keeps track of the phase
6 D: i z7 {3 V3 S; i" n8 B num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
* f+ y2 |& W# Y1 [* G' W current-light ;; the currently selected light o( O$ _7 v- w! S& c+ ^$ ]
1 Y& E# r; G/ | Y; \- Q ;; patch agentsets; b& }+ ~- r. i
intersections ;; agentset containing the patches that are intersections
8 m1 z4 b: e5 f/ D! D$ m+ G) b* v roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle, X0 N; [: n _ f
up-car? ;; true if the turtle moves downwards and false if it moves to the right
. J7 C! E9 w! _) n8 b wait-time ;; the amount of time since the last time a turtle has moved6 p. ^; i/ O' v& h
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4 k, \8 {/ W9 o7 i! u! jpatches-own
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7 y4 a3 {, h1 l$ r8 s* }4 u' x- ~ intersection? ;; true if the patch is at the intersection of two roads1 `$ u' e0 Z$ K+ A& `3 |
green-light-up? ;; true if the green light is above the intersection. otherwise, false.4 k z) p% V+ H
;; false for a non-intersection patches.
- t8 [* R# @6 l$ C, C" u' Y my-row ;; the row of the intersection counting from the upper left corner of the3 B1 y7 L; I5 _- N# b
;; world. -1 for non-intersection patches.
( {1 a, J2 L4 J( _6 @9 k my-column ;; the column of the intersection counting from the upper left corner of the6 w5 H' b. h* g2 _$ f M% s. w
;; world. -1 for non-intersection patches.% y& e3 ~" O& ]7 E" V* [7 G) E. H
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
% a$ f5 ?1 H, s$ U7 |! P8 J auto? ;; whether or not this intersection will switch automatically.- b$ n; ?8 b- b0 w
;; false for non-intersection patches.- Q. I; Q0 s% j$ O
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/ ~- c- @9 r9 i! t$ m1 p u;;;;;;;;;;;;;;;;;;;;;;
; m# y7 o S$ y7 d9 a;; Setup Procedures ;;
2 t9 t- B' i! v3 l4 v1 n: n;;;;;;;;;;;;;;;;;;;;;;% x" I5 J. I+ V% y8 f+ K
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;; Initialize the display by giving the global and patch variables initial values.3 Z' j2 B( q4 Y" U% ~' }
;; Create num-cars of turtles if there are enough road patches for one turtle to
7 `8 O4 X. T# F# s9 v0 W;; be created per road patch. Set up the plots.2 w$ x E; m/ z! e( p. e4 y
to setup
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" M5 Q* w. i$ y+ { setup-globals5 Q9 W7 t$ I: u9 s. j! d* |5 {
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;; First we ask the patches to draw themselves and set up a few variables
# F) q: v( D7 P* y: k* H' n" ~& } setup-patches0 \5 y2 ]8 ]9 G0 D
make-current one-of intersections
, {! y; R2 A" U! I* ^7 x: n/ M L label-current
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set-default-shape turtles "car"* U9 Q- j B) Q1 f% `
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if (num-cars > count roads)% L8 W! l, g9 O x; O
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+ v" b7 f* _1 N0 }4 F user-message (word "There are too many cars for the amount of "
|6 m. L2 `0 }6 t: R: ]1 m "road. Either increase the amount of roads "9 h/ Y" J3 q( \8 n b! }4 q3 n
"by increasing the GRID-SIZE-X or "- j2 @ c. v$ ^1 a5 s0 l, d' S
"GRID-SIZE-Y sliders, or decrease the "& p/ P$ j9 a8 c
"number of cars by lowering the NUMBER slider.\n"# x! e* _: d7 m
"The setup has stopped.")
/ R) m/ k( Z8 `$ I1 S/ o0 V* I! r1 ] stop% z. Q4 F6 i, L5 T8 ]7 Z
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color' Z M( Q$ @* v% X
crt num-cars8 f7 Z% L# x1 k# k; y f% ]0 Y
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setup-cars
6 g( b2 H$ z! }8 W" e p& G set-car-color
" T D* J' \4 C( U1 E5 w' N1 p5 h: ^4 d record-data
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( T/ J& `) S1 C7 q9 P4 h4 ` ;; give the turtles an initial speed
/ W0 c X b+ ?# ]. L ask turtles [ set-car-speed ]" D2 U- n2 y9 l7 f* Q9 F9 Q3 x3 S
" i. p2 w3 K8 l* d' B1 Z reset-ticks
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;; Initialize the global variables to appropriate values7 s6 k3 n6 } @) B
to setup-globals* W+ G' k! U6 U; k) d
set current-light nobody ;; just for now, since there are no lights yet1 S# y. d0 q, G$ ^
set phase 0! t: N3 V Y0 d6 c' ?% R
set num-cars-stopped 06 R% g6 N0 ?" g3 R/ k7 O* A8 y
set grid-x-inc world-width / grid-size-x
3 _- e( s0 b% G% Z4 ^ h set grid-y-inc world-height / grid-size-y4 e9 U, P) T- B2 Q( K$ I5 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. [& E. v3 i6 Z, a3 {6 u# O& j1 _
set acceleration 0.099
" K' M/ k7 b0 i8 B7 @4 R! F, `end
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9 f1 l' k1 O% r6 o;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
$ U5 T- J9 y3 I7 @+ g+ M8 i;; and initialize the traffic lights to one setting
, V% \* I% u' r6 ]9 _& Ito setup-patches
5 Y0 d! d/ O$ U. t ;; initialize the patch-owned variables and color the patches to a base-color
0 c4 }2 x' p* `: O. u- w2 G( o ask patches
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! q$ g7 s. O# _) C5 d* C( g set intersection? false* k4 C h k. _& s1 t- j# h+ S# ]
set auto? false1 I2 y9 R; L' s4 g3 f* I2 Z
set green-light-up? true
+ W9 ]0 i; e8 X9 {, v) f set my-row -1
t2 c! S* B, f- J( c2 @ set my-column -1' \' q# t& Z0 ~& C
set my-phase -1+ K" `$ E% y0 f- M$ z2 L+ w
set pcolor brown + 3
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) \8 q2 g- X+ Z& i# F$ ?! { ;; initialize the global variables that hold patch agentsets( {6 E; L4 J+ s3 D, O# {
set roads patches with
/ ?5 L0 r% @1 \/ r1 e$ P [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or+ k5 F' d! ], n2 O3 Q! y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ D7 V. o" M- B
set intersections roads with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 Q! u: X+ ^# x0 o4 y; B
: A/ _5 c: a' O ask roads [ set pcolor white ]
; x; ]- I i7 k, m, o setup-intersections) @7 `, }/ ^' [7 a' F1 b0 }
end4 K& G( m* a& J {. \! Y
其中定义道路的句子,如下所示,是什么意思啊?
. _; R1 E: b/ e Q1 `* H set roads patches with# r, U$ A; R, J: K2 M% g
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 n% q/ \% S v% d7 [, L (floor((pycor + max-pycor) mod grid-y-inc) = 0)]! G# a1 E( | t2 ^' x, _' ^1 j1 z1 s
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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