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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。/ G7 V. ?& S) C X2 t
netlogo自带的social science--traffic grid这一例子当中,
3 E( R) i/ R% C; Y. _9 ^# Pglobals3 x* [$ P% G" T3 t
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- ]2 C& p1 ?8 V" a3 i% R4 U grid-x-inc ;; the amount of patches in between two roads in the x direction
, J+ r& E* O* H grid-y-inc ;; the amount of patches in between two roads in the y direction6 g" F4 ~' @. s8 }9 j
acceleration ;; the constant that controls how much a car speeds up or slows down by if* u K, r1 M6 {5 {! @' D5 ?
;; it is to accelerate or decelerate: N# g) x- \" u0 {" Z6 E
phase ;; keeps track of the phase
3 S$ f" `5 h: |4 z$ s1 F num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure- r* g( a7 Q! U
current-light ;; the currently selected light
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;; patch agentsets
7 L6 X3 c' {, ^1 Z+ S& Y$ s0 {# [6 c intersections ;; agentset containing the patches that are intersections
9 ?0 l$ T. z& g \ roads ;; agentset containing the patches that are roads
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turtles-own
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) U7 @1 d4 q9 c6 |. ?: v5 k8 v speed ;; the speed of the turtle
( e$ D8 _2 J4 Z5 q! _ up-car? ;; true if the turtle moves downwards and false if it moves to the right2 B4 b( g: Q+ |# q+ M/ w3 T
wait-time ;; the amount of time since the last time a turtle has moved& I: d- l. _/ _# @2 g4 N+ K7 l/ e
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4 W f7 p% s: N9 q( Y. U0 v' ]4 Cpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
& w3 G9 d3 \& O- x! L2 F3 Z! } green-light-up? ;; true if the green light is above the intersection. otherwise, false./ M! A8 Z6 o6 h* s+ K5 b
;; false for a non-intersection patches.
% _% s# A8 U1 Z( M) \+ W. S my-row ;; the row of the intersection counting from the upper left corner of the
1 t! Q, l U1 A& k5 e ;; world. -1 for non-intersection patches.7 ]) Y* W8 d# {5 w9 t6 f
my-column ;; the column of the intersection counting from the upper left corner of the
6 I; e2 }# }/ k& A/ B/ b9 L ;; world. -1 for non-intersection patches.( s. |; k; ?1 \2 r) B3 [
my-phase ;; the phase for the intersection. -1 for non-intersection patches. v+ j, Z& [" C
auto? ;; whether or not this intersection will switch automatically.! o5 M2 c9 }. h- ^7 c7 b; d
;; false for non-intersection patches.
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$ c! S0 z: g8 x: j, N" x; `;;;;;;;;;;;;;;;;;;;;;;
2 E9 W8 H- p. t& i;; Setup Procedures ;;
" ?/ [4 E; b2 e, X; ?7 l;;;;;;;;;;;;;;;;;;;;;;
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4 @4 v2 O9 t& O2 g) V, h- c;; Initialize the display by giving the global and patch variables initial values.) n+ G$ U6 \0 M; r4 D. l% `9 G" e7 a
;; Create num-cars of turtles if there are enough road patches for one turtle to
5 u7 ]. N7 h9 f8 F;; be created per road patch. Set up the plots.
1 b$ }! x8 ~$ c. A, ?8 d$ y! Dto setup
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setup-globals; x6 ?+ }+ V) A. @3 A- e( B
% e' z! X0 [ A& { ;; First we ask the patches to draw themselves and set up a few variables$ _( h3 d% D9 Y
setup-patches
- }1 Y. n! y1 S3 o* p make-current one-of intersections
7 K. h2 Q" V; y& W& Y. x' c8 r2 N label-current- W* ^5 Y3 ]( |5 M( v- J
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set-default-shape turtles "car"/ k' K/ |7 _ O# y. Z$ h8 m; t
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
7 o/ c0 N. a: J; P$ u0 | "road. Either increase the amount of roads "
: {$ A6 k1 M! G2 X "by increasing the GRID-SIZE-X or "
+ g/ ?$ O! ?( d. a "GRID-SIZE-Y sliders, or decrease the "
_+ S5 ^# u$ X. |* q "number of cars by lowering the NUMBER slider.\n"# [+ ~, t D' v3 y* V i" R( Q8 O3 m
"The setup has stopped.")4 t0 U: }$ [% Q
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
* r$ z- L8 \ c4 m crt num-cars
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. F1 S6 h+ t: i$ y1 c8 ] setup-cars
0 h( D! ?0 b- B- d& g! i6 Z set-car-color
! }' H, k! {- f$ p$ ]0 b/ u record-data
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' t8 C& c* H$ B' @ ;; give the turtles an initial speed6 V2 t' L6 M- l7 t1 Q
ask turtles [ set-car-speed ]
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, V" O% I* z) ~# \9 w% ~, U6 J reset-ticks
1 q# }% q( m' f6 R, A( O1 c" k4 Yend
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; @: H* R/ A. I: S;; Initialize the global variables to appropriate values3 N2 O1 b5 l) @ L+ V1 _: g
to setup-globals
3 h& E) O R2 n4 t9 V7 I6 a set current-light nobody ;; just for now, since there are no lights yet' I1 Q8 D- N: ?- ^
set phase 0# \+ P! D4 y$ |+ F
set num-cars-stopped 02 E1 k* }' }4 C2 g9 x& L1 t4 O0 w
set grid-x-inc world-width / grid-size-x+ a e, L. a; l4 }& v' ?3 f+ A
set grid-y-inc world-height / grid-size-y6 s( l# m3 j9 X# A; n ]5 a9 |
! u; `$ `) M! m9 t' N1 B ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary. `; B e) |- ?5 k: ?
set acceleration 0.099
& b/ t8 V* X# c, `7 c* nend
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* C) B0 R# f0 w& R5 M' L; e% h2 @;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
. e; u n( J+ d3 q4 U0 i;; and initialize the traffic lights to one setting$ [9 l7 k" s# P
to setup-patches
9 t. J( n+ |* X" Q3 G ;; initialize the patch-owned variables and color the patches to a base-color$ V, E' R, F' z0 e4 I
ask patches
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0 C: Y- F* m) J set intersection? false9 L. f! w2 A9 I( ~7 }/ {
set auto? false# f; F% c$ q# C: s' x2 w
set green-light-up? true# k3 }- h2 U$ L( P
set my-row -1- S8 {# b6 H n( V9 X
set my-column -1; _3 E0 N( Y7 x- `# L1 c
set my-phase -1
7 P$ Z( G+ q8 u2 r- T, V" S set pcolor brown + 3' r) f/ ^# S: x3 A7 w, K
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;; initialize the global variables that hold patch agentsets
4 Z, E/ F1 h V0 E3 v set roads patches with
/ e9 H, ]5 F- m* I [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or1 r- O& Q' s: K& u# i6 O( L
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
, _, T. Y1 C) v6 W5 d set intersections roads with
; d- G( Z% G7 `. _- n [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and; L4 _$ I( y. W% ]) l# ?& H' g- E
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]; R6 N$ l; ~) A- l! R/ a; l
/ G; P0 V- Q" x8 A ask roads [ set pcolor white ]# `/ J/ v/ p% ?+ ~. _" ^0 S/ [
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?
2 L( T O! K1 {! D set roads patches with! C- G, ]' J, E/ L9 p" B S. V) y
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
2 i) P; K, Q G: k$ k) d% S% M (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
8 O4 F+ F" x, g* Z' V) p3 u' y2 e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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