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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。
O) T( j) m; A3 vnetlogo自带的social science--traffic grid这一例子当中,
/ c* }, l# H- b7 P* O6 J& f3 F; aglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction2 X: l' T* H. C8 p5 X4 L* j! `: f
grid-y-inc ;; the amount of patches in between two roads in the y direction
' h+ G" q% Z$ n. } acceleration ;; the constant that controls how much a car speeds up or slows down by if7 h+ L4 k9 F7 j0 {- k3 s
;; it is to accelerate or decelerate: i) `7 F; ~, f! z* K
phase ;; keeps track of the phase* \* C* A3 k$ {# j: l( v
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure- L6 }! _0 ^& K5 \& ], I
current-light ;; the currently selected light8 i7 a8 n8 @- M% K) V: W3 f
% U1 k3 W' k% U- E; s ;; patch agentsets
5 s$ N5 O3 J( l! A intersections ;; agentset containing the patches that are intersections7 q) @6 w( a+ z( _# s
roads ;; agentset containing the patches that are roads
% `3 M3 U5 B4 T+ O( T6 P( O+ [, x]
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1 u" [( k5 }$ v9 a% F- J6 M- dturtles-own
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speed ;; the speed of the turtle) n. A2 L8 w7 X% b% s
up-car? ;; true if the turtle moves downwards and false if it moves to the right* o5 Q8 V1 P: E8 {
wait-time ;; the amount of time since the last time a turtle has moved) V( B. K& s/ x! C
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9 o" n; r( O# g( opatches-own
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7 A% Z! h" [$ U% f+ a intersection? ;; true if the patch is at the intersection of two roads
' _, r( E1 h, B- _ green-light-up? ;; true if the green light is above the intersection. otherwise, false.
1 k4 A- |+ \! R% m ;; false for a non-intersection patches.
$ {: z9 n4 f( `6 n4 V my-row ;; the row of the intersection counting from the upper left corner of the
. Y: T0 h- |5 h5 ?8 g ;; world. -1 for non-intersection patches.6 r# Y# Y& n5 s: q3 w
my-column ;; the column of the intersection counting from the upper left corner of the- a" a, I7 S, G2 j! |( I: I
;; world. -1 for non-intersection patches.1 Q: A- Q! f1 _$ x2 {+ r
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
1 [: P3 s. p+ i$ ^ auto? ;; whether or not this intersection will switch automatically.
$ e( \! L2 s. r R4 U7 }* A ;; false for non-intersection patches.) q7 j; u8 J3 f9 g8 e( s
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+ ]' V, o6 y- A# p0 W;;;;;;;;;;;;;;;;;;;;;;
t3 N4 X$ P2 H' A+ \ }( O) F Q;; Setup Procedures ;;- D: R% U# t* e0 Z0 @* c w
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0 Z" m! Y b+ C0 _;; Initialize the display by giving the global and patch variables initial values.: q3 n2 x' L! m* C$ R; X& O- T2 Y
;; Create num-cars of turtles if there are enough road patches for one turtle to
4 ?( v9 W" d" T% r" D" ^;; be created per road patch. Set up the plots.
7 d; z, T, O* D! F( k8 yto setup2 K& J( x1 j& W1 R/ X- M" u
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setup-globals* n+ R% Z H9 ^; A- I
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;; First we ask the patches to draw themselves and set up a few variables8 j- o" { Z' K. H( C
setup-patches7 L7 O, m3 ]7 N3 Q
make-current one-of intersections
, l; s6 r4 p- ]9 s& I label-current
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set-default-shape turtles "car"3 `( U1 V+ C# {& \+ B5 V; N8 ^* Y. a
. E. g/ \ K& K. x if (num-cars > count roads)0 J$ a( G4 q5 C
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& J3 g' m. R! C! I! B user-message (word "There are too many cars for the amount of "
8 M0 ?; ?. \2 D! P( y% _" Y& r "road. Either increase the amount of roads "
4 B( e7 g c7 t8 r8 k v a "by increasing the GRID-SIZE-X or ": G6 ?6 ?- ?! R, ?& T2 ?
"GRID-SIZE-Y sliders, or decrease the "
! K& E0 e( ^1 ^0 W( ~ h$ x; O "number of cars by lowering the NUMBER slider.\n": W# X& l9 F p) k
"The setup has stopped.")
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
2 C& m; ^: }" g+ m2 x crt num-cars
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- j; P% L" P, Q k setup-cars
1 i {( X0 k/ c# y3 A# z, W( S set-car-color$ e) L) p! ~. ~/ @! g
record-data3 B& k; B4 Z/ z' \! s# q, z; q
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;; give the turtles an initial speed
( t) V4 Q: U0 B1 g! c ask turtles [ set-car-speed ]
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reset-ticks
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2 n) B! N2 l7 C2 B4 T! c;; Initialize the global variables to appropriate values" F! m- p' C) e( r
to setup-globals- B( V) K3 @% R
set current-light nobody ;; just for now, since there are no lights yet
) P* x! _6 e4 P" K+ Y# ?+ s set phase 0
& x- v% m7 L$ Z g set num-cars-stopped 0' B0 Y7 m4 D$ b+ H
set grid-x-inc world-width / grid-size-x1 v& Q8 [ }* i% a1 k/ i
set grid-y-inc world-height / grid-size-y) }- l0 h; j) p6 Z2 @7 u0 _* D
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary6 {( N8 ^0 `8 q% f2 s
set acceleration 0.099
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4 Q) B" y7 q" l e;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
1 v# e* M: W x+ z. Z5 K;; and initialize the traffic lights to one setting
- X$ P1 d- H" w7 X" O( Z/ xto setup-patches' M) Q" J4 v$ y/ o* v, k" l, B% B
;; initialize the patch-owned variables and color the patches to a base-color
' I+ @( ~0 `6 T9 R ask patches* ^% ~5 j. T. `( t. U
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set intersection? false
4 W- ]7 [* A& H$ |( p# F5 ?1 @ set auto? false
( T6 s- z. t; E" A5 v- C set green-light-up? true
6 l1 \; W, V8 O. ^+ i/ ?! C set my-row -1
9 b7 L' r/ z" C: r0 n" { set my-column -1
z+ _3 B( C% O9 Y9 c4 B set my-phase -11 P$ s7 k+ _* R& T# f$ G. }+ J. ^
set pcolor brown + 38 Z% \# W1 J5 V* ^3 k
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7 Y! [$ j, O R" h) z- I! v ;; initialize the global variables that hold patch agentsets- S; C7 l- b( ?; T! C
set roads patches with
% |' Z T9 U% D; r [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or6 P1 J! m- X! Z0 C( L
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]% I4 `' e" g. C
set intersections roads with
" w8 \/ h7 @$ O9 e9 W0 [$ o [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and- k' }. q5 z" y$ x4 N
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 `, q9 g2 E! L, g$ K5 @
4 X# F3 k5 T9 x- l& B2 { ask roads [ set pcolor white ]
5 v6 r* c0 q3 q( 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?
2 Q1 k* m0 b- v: ?1 l set roads patches with
) f3 G9 {: \" F [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
$ O0 ]" p, S# ^5 S6 O (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* b3 B; W+ ]. a) N, P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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