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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。
2 g" d8 O" x/ ] Snetlogo自带的social science--traffic grid这一例子当中,
% s! s) n! q! s8 F+ h' [1 j/ l* W. ^globals* b' U% c9 T2 T3 k. H4 ~
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grid-x-inc ;; the amount of patches in between two roads in the x direction# k% M- W- f& P) ^
grid-y-inc ;; the amount of patches in between two roads in the y direction2 _- _6 u0 x* L% M, q
acceleration ;; the constant that controls how much a car speeds up or slows down by if
& X/ q6 c: _. c6 R, ` ;; it is to accelerate or decelerate5 X+ X$ J( J X7 A9 r; z' q; n
phase ;; keeps track of the phase
. x7 S; Z7 Y- k' S# Q num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure3 G( f" J, R( N4 o2 L; c
current-light ;; the currently selected light* J9 x! r, t6 o
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;; patch agentsets
. f, ?+ F$ I7 c intersections ;; agentset containing the patches that are intersections
& w( g/ F2 i. w- E3 I& e! Q roads ;; agentset containing the patches that are roads
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turtles-own% I4 G: N: Q& `2 C; `7 T3 r- X8 U
[
9 h$ l x) L- s% M4 c/ F% _ speed ;; the speed of the turtle
0 [1 Y6 w" m4 @1 h/ B& T up-car? ;; true if the turtle moves downwards and false if it moves to the right" m* d7 p9 g! M
wait-time ;; the amount of time since the last time a turtle has moved2 U# O$ _% W1 \2 L6 P
]
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6 ?1 F8 `- q8 l6 u; Ipatches-own1 ^& @7 c. p1 I1 B; Y
[
" P: S9 X+ u* E+ c" U; }- L intersection? ;; true if the patch is at the intersection of two roads
7 L; P0 ~- j( d8 A* N green-light-up? ;; true if the green light is above the intersection. otherwise, false.3 j: q0 n2 Q& Z* {7 j* o' u3 @
;; false for a non-intersection patches.. q( x! e/ k M1 H0 }8 ?& o2 [; C/ K
my-row ;; the row of the intersection counting from the upper left corner of the q" W, B( O0 H* B
;; world. -1 for non-intersection patches.
8 ]. G; N/ \& E: n my-column ;; the column of the intersection counting from the upper left corner of the
+ t F" y* _) G- t! n; l+ U4 t ;; world. -1 for non-intersection patches.
- c( B+ B/ A# W! D; Z" p my-phase ;; the phase for the intersection. -1 for non-intersection patches." m: c, E3 x- ], [
auto? ;; whether or not this intersection will switch automatically.& z7 T6 \, w: h8 e2 j* [
;; false for non-intersection patches.
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5 E4 S" O' H( B8 X7 D# S, i; J* @;;;;;;;;;;;;;;;;;;;;;;
6 M& k7 r, k4 H* y2 @;; Setup Procedures ;;' m' L" Z& i" q- b* i
;;;;;;;;;;;;;;;;;;;;;;3 ]* n4 o5 c0 i1 D
5 H! ~$ I( H' W" M;; Initialize the display by giving the global and patch variables initial values.
" p# ?0 [: o5 {0 f/ X6 Q5 M2 o# ], I;; Create num-cars of turtles if there are enough road patches for one turtle to% m! h9 r# B0 m0 d) H
;; be created per road patch. Set up the plots.
; b0 [7 } M2 C' y, ?/ c0 U. ^to setup
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setup-globals( o. d3 D* T6 _8 k: z6 z
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;; First we ask the patches to draw themselves and set up a few variables" x" h0 D% F. e( y! E: [9 a) q
setup-patches
$ `! g! k% J ~' v make-current one-of intersections4 P5 e: y& V) k3 J" |
label-current/ K* J$ l- d( T8 C
! _$ `+ h+ o& Y! q# ]+ I& r( { set-default-shape turtles "car"/ F6 ]. }7 |7 F' A/ c3 P: d8 V# r) o- V
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if (num-cars > count roads)4 @6 M8 q( S/ f$ _0 I
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user-message (word "There are too many cars for the amount of "
: g3 g) O' e; o; v+ S; O "road. Either increase the amount of roads "; B4 n8 m7 D8 Y2 ^" [
"by increasing the GRID-SIZE-X or "0 [: l- _% ~9 w+ X6 D$ o" z
"GRID-SIZE-Y sliders, or decrease the "
I0 _7 L2 m: ]) w- X( p( m "number of cars by lowering the NUMBER slider.\n"
v4 ^+ j4 Z4 n! e. P "The setup has stopped.")
( L& f" h. Z v% s/ B3 A stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color+ D) O8 F9 J& g9 d# X& H+ Q
crt num-cars
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setup-cars
7 ?; U4 A# v; U: R' n set-car-color
5 |% C; v4 p8 Q. `" @ record-data
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: u$ W2 b" E2 O ;; give the turtles an initial speed( h; \9 O& U8 n& Y9 ~
ask turtles [ set-car-speed ]
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reset-ticks4 l. J% F$ @( @
end
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" }" N8 g1 F1 U6 r$ M;; Initialize the global variables to appropriate values
, @+ W! v3 x7 F" ?to setup-globals
6 h6 i' j2 N( E; a7 N' W, i set current-light nobody ;; just for now, since there are no lights yet
5 D* c4 k; u w0 ?9 I- c set phase 0( `) `$ H) u' l. ^/ ~) ?
set num-cars-stopped 0, Q8 k8 J4 J( i2 h# l* {
set grid-x-inc world-width / grid-size-x
& j6 N5 k8 r5 a9 c, \ set grid-y-inc world-height / grid-size-y
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) @% ? m C3 t) O% S7 d ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary7 Q4 w" R- b9 X7 Z7 T' _, w
set acceleration 0.099 `) I% p/ T1 O/ F0 z, R
end
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8 w1 a n% | E6 M;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
0 r; h' M: v! |$ G) }9 z* N;; and initialize the traffic lights to one setting. y) {- g7 n, D' a! j; J8 [
to setup-patches; p/ f$ ? @9 I: H) n8 N( q
;; initialize the patch-owned variables and color the patches to a base-color+ t" q: l$ A$ Y8 L
ask patches* U1 V* d0 Q' w# n- s* \& ~
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set intersection? false: S) y2 Q! o2 [9 Q) k* f5 U
set auto? false
# q* G/ p' r% A ~" A set green-light-up? true' R. K5 u* n6 M6 ]; |# P
set my-row -1
4 W/ v) J) f5 i7 I' J! V set my-column -1
5 R* U& A$ _6 D set my-phase -1' M. m: R/ u' Z2 i& g8 H1 I
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets3 p! O$ \7 H4 h
set roads patches with: k4 s: I3 _! c4 V! ~$ J( A# O7 f! ^
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! \' h( q/ T" J* { (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
4 N6 V$ t8 J, v4 ~) t5 o2 b7 \ set intersections roads with
3 B8 a6 F1 K# d( I [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
: q9 f) t. V4 c" @2 u- P (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]% c9 z! r. q2 p
setup-intersections: @1 @1 t* n( w/ j5 J0 c4 N
end
. ~5 q( [% Z+ E) Z. H* i* n4 r# p其中定义道路的句子,如下所示,是什么意思啊?& j1 j% g. U- f7 C9 _" Y
set roads patches with3 { s1 Y8 q) q. s( c" @
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or; `% Y" K4 |+ U+ \0 b
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]" w6 K0 ` ~& q6 J9 W
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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