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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。
8 Z7 Z" y8 u% d+ D2 J: hnetlogo自带的social science--traffic grid这一例子当中,
. e, E, S" n# U9 ?globals
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2 V3 F; H' W( o, q M4 N0 u grid-x-inc ;; the amount of patches in between two roads in the x direction: M3 q' K3 M8 l
grid-y-inc ;; the amount of patches in between two roads in the y direction
0 _+ M& V: t% [. N* `$ w acceleration ;; the constant that controls how much a car speeds up or slows down by if7 I1 t# p* b, F
;; it is to accelerate or decelerate: F- ]: }) q- y
phase ;; keeps track of the phase
& i8 { Y/ C9 g. M$ }( J$ B( p. [ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure. D r3 e6 _ S
current-light ;; the currently selected light
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# G% o# e; T" s3 w ;; patch agentsets& r$ _0 z0 l, y1 s
intersections ;; agentset containing the patches that are intersections
( E0 y" S' L( q+ m roads ;; agentset containing the patches that are roads A( S r/ l. `' k! m; U8 e A7 @/ |
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; J5 O7 q" E( J w6 yturtles-own) n' Z9 q3 x$ g& V% G
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speed ;; the speed of the turtle! K, j- y& C5 b" N
up-car? ;; true if the turtle moves downwards and false if it moves to the right$ I" k& L* D1 J) |9 h
wait-time ;; the amount of time since the last time a turtle has moved! Y4 v- h7 r4 V5 ^& R% f. r
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1 S+ w l& r3 u7 K rpatches-own
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intersection? ;; true if the patch is at the intersection of two roads( N$ Y& x! O( ]% h
green-light-up? ;; true if the green light is above the intersection. otherwise, false.& H! I* }) ~2 }+ k6 L% k$ W
;; false for a non-intersection patches.
/ z8 p5 L- I. [5 { my-row ;; the row of the intersection counting from the upper left corner of the& u W* E1 l& h5 J( F/ \, y3 d3 Q) Z
;; world. -1 for non-intersection patches.
) P/ w9 b' Q1 A" x0 y) S @+ U6 G my-column ;; the column of the intersection counting from the upper left corner of the
7 V8 u8 |+ O+ L ;; world. -1 for non-intersection patches.* N9 |( M5 ?% j$ \/ c* U+ B* ~
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
0 z. h0 B- x+ b p) u( s! _/ ` auto? ;; whether or not this intersection will switch automatically.
& |$ Z& a3 P4 y m. H ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
6 g/ t" W: I/ X, J5 ~;; Setup Procedures ;;. ~( n8 |( L# K. _
;;;;;;;;;;;;;;;;;;;;;;* C: W- y* b5 U8 [$ E' o" k
6 T! x) `% y9 n3 O' l;; Initialize the display by giving the global and patch variables initial values.
9 e" q" Q: J7 @, z3 m" i;; Create num-cars of turtles if there are enough road patches for one turtle to
8 g" I' p4 f- {" J$ ?1 j;; be created per road patch. Set up the plots.2 x; j9 }7 @. m) B: r; `
to setup q: e! v2 T4 Q/ X: \' |4 f$ a
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
" E3 [1 L$ i4 Z2 E3 _ setup-patches
' n1 S" s' ?9 n* C9 x2 G, l* c make-current one-of intersections0 y, e1 S A8 B$ Y
label-current
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' C, u- r- ~. f9 b$ S6 C9 H. |; e set-default-shape turtles "car"/ _* Z. O- Y+ K
4 a3 [+ W6 q9 s$ k/ \ if (num-cars > count roads)
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2 V% ~; c/ o$ B user-message (word "There are too many cars for the amount of ". }) e% O1 b3 C$ p: y, ]2 y
"road. Either increase the amount of roads "
, d# A) D' [: I0 I( i5 G: Q "by increasing the GRID-SIZE-X or ", m+ v5 {( r7 O) @! |
"GRID-SIZE-Y sliders, or decrease the "
; }7 l! T8 J* l+ k T "number of cars by lowering the NUMBER slider.\n"
5 c X2 _& C; S6 w0 M S; K "The setup has stopped.")
1 S9 e8 {* n" p: i- G2 { stop
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# D* t* o$ Q( R9 b* t- G9 Y ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color5 E" N- s& l. }1 i! c) W' ~
crt num-cars6 S- }2 X% _* E
[
0 K/ ~1 V& w C7 q* i setup-cars
- @7 o/ @$ e7 z. y7 _8 j5 S set-car-color
5 j4 J, o$ z3 o record-data5 D; J" w- k* W! ]
]
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;; give the turtles an initial speed
6 z8 F: L: [3 m& u ask turtles [ set-car-speed ]
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- v' U" ^6 { z: `! y" { reset-ticks
! B, ]4 o( G) G; K& {9 Mend
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;; Initialize the global variables to appropriate values7 l3 p% m/ v) p D
to setup-globals r' N' G6 j" N! n8 ^
set current-light nobody ;; just for now, since there are no lights yet. S3 p6 Z3 C* n
set phase 0
; u4 Y2 w/ @: n& R set num-cars-stopped 0 L' z$ r4 g$ u$ _7 W; i( p' A7 h
set grid-x-inc world-width / grid-size-x
7 c$ A& Z' l2 m set grid-y-inc world-height / grid-size-y+ ?! h, Q% t+ f0 M7 ~
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
0 v& r/ n0 d/ f$ e5 S7 j set acceleration 0.099
, c! j9 y; S- r; e( g1 zend
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' d7 J/ R# m9 a* W;; Make the patches have appropriate colors, set up the roads and intersections agentsets,. {+ |( @% u! S4 q( j
;; and initialize the traffic lights to one setting0 W7 j/ d- {1 _$ A8 T1 P6 ]
to setup-patches
2 P8 ?' v* O, w8 J# t+ j% b3 w ;; initialize the patch-owned variables and color the patches to a base-color
4 D8 z r7 }0 R" ] ask patches* n' w! ]" `* ~, S
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set intersection? false- Y( a: ^5 {' x, |
set auto? false# r# h2 S3 l0 I. N# b
set green-light-up? true
; C: w0 h; p" M set my-row -1) n7 ?) ^* l9 g0 r
set my-column -1
0 s& q& S1 w! t& J) o set my-phase -1; Z( P6 l/ q; Z
set pcolor brown + 36 V* N# k- [* X8 w
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;; initialize the global variables that hold patch agentsets
$ U5 ]) W- e- \7 g7 n set roads patches with0 d7 P5 V" K1 w# d. n/ ?! q" {: v
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
9 u% b, I/ x1 K7 G; i2 X; T! S (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
' z4 E. | G# Q* i set intersections roads with
+ m5 g/ E# d ]7 n! C [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
( c( u/ B- }) Z" ]+ u (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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7 \8 Q3 Q, b' f: F: T4 G ask roads [ set pcolor white ]* p; |- _) a; Z: I. e
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?
% Q- T% U8 V, E0 [+ k set roads patches with
+ J4 W- P8 y- r- Z+ ]8 U [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: ^# t5 D$ s- `% v c p- p (floor((pycor + max-pycor) mod grid-y-inc) = 0)]) B6 L8 Q, t3 K/ u" D
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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