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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。1 A; P" M( c3 G' T0 V
netlogo自带的social science--traffic grid这一例子当中,
H7 z K5 e; K r0 N) pglobals" G9 w+ R1 C- V# t+ ~2 J
[
* r( i! a; ]2 B2 T. S2 W grid-x-inc ;; the amount of patches in between two roads in the x direction
2 J1 `# q& o( t8 e grid-y-inc ;; the amount of patches in between two roads in the y direction
5 z9 U. s$ Q$ U% [ {8 _ acceleration ;; the constant that controls how much a car speeds up or slows down by if
/ _3 I; h1 }9 _: i* O ;; it is to accelerate or decelerate( J, @1 B$ B% ~& ]; E; |
phase ;; keeps track of the phase! K; S3 B" L& L3 s& \/ y' y
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
$ }% o: e% u5 t+ e3 \1 ]' W current-light ;; the currently selected light0 r' n/ E. C B8 `: I: s
+ f% j& ~9 N3 @- W1 k- _2 q- \ ;; patch agentsets
, M8 M5 V* h/ z0 f' o intersections ;; agentset containing the patches that are intersections* T0 G4 K; s! p3 d) P
roads ;; agentset containing the patches that are roads4 x* W5 K$ E3 [/ d
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5 }' Q: ?" C) Nturtles-own
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6 d3 k& i f9 ^6 f speed ;; the speed of the turtle( j7 q3 l* W$ U# L" K7 a H4 K. f
up-car? ;; true if the turtle moves downwards and false if it moves to the right( o$ p" n$ }7 p A W8 R3 H' R
wait-time ;; the amount of time since the last time a turtle has moved1 T( l" ^) Y# B$ O1 S$ S" X5 p. u. p; ^
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patches-own7 P1 w' p9 w* S& Q: J7 Q& a
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intersection? ;; true if the patch is at the intersection of two roads
/ _# y0 ?/ w. y! S4 u" p6 u green-light-up? ;; true if the green light is above the intersection. otherwise, false.8 M, D7 n- g- j
;; false for a non-intersection patches., [5 C" I. O% E1 A
my-row ;; the row of the intersection counting from the upper left corner of the
% P, J8 H5 L8 U3 U3 n6 B ;; world. -1 for non-intersection patches.; J6 d/ | i8 u1 j) U
my-column ;; the column of the intersection counting from the upper left corner of the
1 U* b3 n' ^1 @; @+ @ ;; world. -1 for non-intersection patches.
3 q7 M3 N' E( y# r* Y5 c my-phase ;; the phase for the intersection. -1 for non-intersection patches.
I" C' p# k8 J p) e! u+ G auto? ;; whether or not this intersection will switch automatically.
4 X/ @3 @& ]$ B$ u6 r) R ;; false for non-intersection patches.
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Q8 B4 L1 |0 K7 u- Q" |5 z;;;;;;;;;;;;;;;;;;;;;;8 S4 ^; a% k7 y5 q* p
;; Setup Procedures ;;* I& {# y2 u. y; e
;;;;;;;;;;;;;;;;;;;;;;+ o& @( C! H | o( S
# l/ |% {+ Z4 v0 ~* F;; Initialize the display by giving the global and patch variables initial values.
7 L6 y& f3 n. b6 |1 o) H;; Create num-cars of turtles if there are enough road patches for one turtle to: k4 n; x1 `4 K# Q0 t. w- ~- V
;; be created per road patch. Set up the plots.
" u; t# d6 b l- K5 T" z. Uto setup
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2 [9 Y7 ?8 S/ Z setup-globals
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/ x9 P' m% q& ?- g; o. H' j ;; First we ask the patches to draw themselves and set up a few variables
3 z7 I! A, W, s* G9 M5 k# S* ~ setup-patches
! V f" j# k' z$ ^ make-current one-of intersections
) k% V, @% _ o) H2 G# k+ Q6 s label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)! E- S3 Y! x' ]( T7 |7 {) T
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user-message (word "There are too many cars for the amount of "
! [$ u+ l; ~ W. q% @: V; g "road. Either increase the amount of roads "
, t% A/ J) A8 I7 x1 B* d' T! K4 b5 _ "by increasing the GRID-SIZE-X or "+ P/ J) N5 v* S N0 g
"GRID-SIZE-Y sliders, or decrease the ") X7 e: N) ]+ ]) X# `5 x
"number of cars by lowering the NUMBER slider.\n"
2 }" i& r# E$ X "The setup has stopped.")
6 }# _( q' H, Q: w% ^ stop- j% G9 \4 p; \- o$ z' o1 u
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color7 x8 q9 A; i; V$ J2 K8 X6 [1 Q
crt num-cars3 ~7 _* p I5 t' B) k+ C9 _9 h
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setup-cars
$ P2 u7 c8 [( u* H. K' V3 J set-car-color
* h2 u5 W& b. Y; a/ P+ J: s record-data
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;; give the turtles an initial speed$ V9 a: B& V# D7 p* f3 A
ask turtles [ set-car-speed ]1 C& l5 y' j: j- H
O6 b, ?3 k6 H) p. n* n9 L& J reset-ticks
9 `! M% }3 S' u8 qend
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0 f: l S4 m J4 h: ?, g;; Initialize the global variables to appropriate values
' t# l6 ?0 I$ o: ?' \to setup-globals- \" h% N) A0 g3 v/ ~0 P V: Q
set current-light nobody ;; just for now, since there are no lights yet4 U J* H6 [" ?+ D
set phase 07 j9 c# c) _( S9 e
set num-cars-stopped 0: \& |$ o( G1 O6 O/ ~' Q; C
set grid-x-inc world-width / grid-size-x% o E* h$ ?, B0 f
set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
- C o, j& T, E set acceleration 0.0998 I% R& z& s/ p- l, n5 E
end, E9 f( }2 u1 a1 N) |
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,6 a' `) \3 b0 `' Y9 d# |+ T) G: P
;; and initialize the traffic lights to one setting
- Q+ S- X; C# Z7 p* {to setup-patches
8 S& p- F! g: E; N5 G ;; initialize the patch-owned variables and color the patches to a base-color6 Z5 U, f7 |3 t7 z% f( G0 f2 Y
ask patches
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set intersection? false2 O5 b' o E8 J b5 ]7 Q9 x9 ]
set auto? false# D& R/ O0 q& c! ?+ ?; _0 m, d) L; x, W
set green-light-up? true
L( b: ` x* k. f set my-row -10 z6 Q% \7 ^$ T( h7 q
set my-column -1
7 ~. B4 `+ K# z- V9 |5 ^ U set my-phase -1
: E: L, }& ?0 i set pcolor brown + 3
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# q" Q# E& V6 W r ;; initialize the global variables that hold patch agentsets4 i7 U! u8 G5 f' @
set roads patches with
, @& J4 O* H7 U/ t/ } [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 i7 C% ]0 w% L& F e1 M (floor((pycor + max-pycor) mod grid-y-inc) = 0)]' s1 e; d: T& d* y' ?
set intersections roads with
8 N2 J* c/ F1 O( D3 {$ T7 E' \ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
8 ]3 W/ u3 V) j- N* N5 {9 K& t (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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. ]5 K9 j/ i5 [% A i1 [* H- Y ask roads [ set pcolor white ]4 V9 _/ h1 `2 i! _( ]$ }1 n
setup-intersections
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& `( @9 ]* @( K' ~其中定义道路的句子,如下所示,是什么意思啊?5 a' u. S G* v
set roads patches with
; s' I4 u% R$ E- w [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
* \. [0 u0 w- f- M (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ ~/ ?/ }0 ]! ?5 Q& F5 ]* 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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