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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。- E( z+ a' R$ s
netlogo自带的social science--traffic grid这一例子当中,
9 u# u D2 j7 Dglobals/ D1 j0 _! m& u
[
- A& m" _. V. o' N' D l7 r grid-x-inc ;; the amount of patches in between two roads in the x direction
* K5 T* c" W* V* X grid-y-inc ;; the amount of patches in between two roads in the y direction' k1 V9 P1 y2 X* `7 ^0 b
acceleration ;; the constant that controls how much a car speeds up or slows down by if. k5 K2 J0 U+ C; x/ {
;; it is to accelerate or decelerate
7 G1 `3 L6 o! p/ h" j5 O phase ;; keeps track of the phase
4 ^1 O9 j; @ `) l num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure+ e" P! J" o! x& L" H- `- N
current-light ;; the currently selected light
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! {3 j9 g$ x6 Z& n+ A3 e ;; patch agentsets. L; l1 ]0 O- q% @/ b4 }
intersections ;; agentset containing the patches that are intersections- S1 W. D5 T$ t) W7 B* X: z
roads ;; agentset containing the patches that are roads) {( h7 y1 H, z% x
]
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" l2 S! J' r5 `, E- uturtles-own
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speed ;; the speed of the turtle
6 _. ?/ m0 z5 m1 r8 J% `+ d- P. V up-car? ;; true if the turtle moves downwards and false if it moves to the right
2 _- M) o4 w1 x! B5 e8 m wait-time ;; the amount of time since the last time a turtle has moved
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patches-own6 R( x+ J+ b: [: D$ ?/ N/ ~
[) ]1 L' F3 V( _( @1 h& ?6 ^
intersection? ;; true if the patch is at the intersection of two roads" A5 }3 P [2 i2 U0 G& A9 k/ h7 Q
green-light-up? ;; true if the green light is above the intersection. otherwise, false.) n. m; I/ C( q! o4 ]8 m
;; false for a non-intersection patches.
1 o2 T7 r" k, a9 F! j9 O. t- e my-row ;; the row of the intersection counting from the upper left corner of the+ | r$ a2 C4 i: S+ }, y1 ~, z- t
;; world. -1 for non-intersection patches.
( b' W7 |! @; A. Z5 S my-column ;; the column of the intersection counting from the upper left corner of the/ e, s2 l+ k: B& k
;; world. -1 for non-intersection patches.
: e# h3 D( z9 U& |0 j4 ^8 g8 c my-phase ;; the phase for the intersection. -1 for non-intersection patches.
/ ~% p: X( E) \! K auto? ;; whether or not this intersection will switch automatically.& R! B" {, ?( W: {) I3 Z
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;8 `/ f; T0 u6 J7 _
;; Setup Procedures ;;8 o7 i: x) n9 n! d4 g. _
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.. p& t0 n) z* ?! [6 ]
;; Create num-cars of turtles if there are enough road patches for one turtle to
! Y( _3 E. \6 s;; be created per road patch. Set up the plots." ]( ]$ g0 X; L
to setup+ r) u2 {; K# J1 `5 c) t* ~8 k
ca% a2 L: U, M: g. I
setup-globals, u7 r# y* T2 d- f/ i |
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;; First we ask the patches to draw themselves and set up a few variables
5 B& G# }- D# @ setup-patches9 C0 ~3 T+ \0 o5 i& @7 A
make-current one-of intersections
) V$ `9 r2 @6 [ label-current
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set-default-shape turtles "car"% P3 f B$ N8 }3 D- N
4 t7 l* }* h4 k/ t if (num-cars > count roads)
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9 x/ @- J: G5 I: k2 ]' _: L user-message (word "There are too many cars for the amount of "
! T5 h7 Y* l9 n2 `1 K& q "road. Either increase the amount of roads ". Y5 B3 Q, D q# s
"by increasing the GRID-SIZE-X or "
+ F% Y) @1 @6 n ?* D9 h "GRID-SIZE-Y sliders, or decrease the "
! b* r' O2 l* _2 [! { "number of cars by lowering the NUMBER slider.\n"
1 X9 o" c& }4 z$ b' \5 P "The setup has stopped.")3 p' T \; _, Q: I& C
stop% b& @7 j7 N# s1 X: J) {) Y' j
]
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V8 h% I1 T9 x P. q ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color+ y# p2 n* x4 g$ t- E6 N
crt num-cars
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6 [; `( y0 W; j6 j8 o W setup-cars
7 Y" Z4 J0 K* F, R: V4 [ set-car-color
7 Q- d; S" `1 i) G& @ record-data9 m7 F/ s1 J z! Z4 Z
]
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;; give the turtles an initial speed( A) L1 }0 h. M; C
ask turtles [ set-car-speed ]
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2 r$ i3 F* k* } Z) }1 _ reset-ticks
, M$ h. `* T" mend
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;; Initialize the global variables to appropriate values( V5 Q) N2 s, w# m; Q+ {' K! _, o
to setup-globals: x9 w2 i' O1 I& R7 R- q
set current-light nobody ;; just for now, since there are no lights yet- @* o3 z6 r. I; v! h7 h
set phase 0/ F( {9 D A q. [. ]& e
set num-cars-stopped 0
$ R1 {, b$ r9 U" x set grid-x-inc world-width / grid-size-x
$ o2 @+ D* c& f9 b3 j6 a set grid-y-inc world-height / grid-size-y
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) |$ U& Z3 m3 {0 p Q A ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary' l8 Y) i! [' B) k) j$ M
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
6 v" X0 S* }6 n;; and initialize the traffic lights to one setting
. f* _( A* E! I8 t4 p5 kto setup-patches5 p7 z/ Z" I7 G% d& B- N Z
;; initialize the patch-owned variables and color the patches to a base-color9 ?. B5 u$ ?8 p! l Q$ W$ I8 g/ I
ask patches
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set intersection? false, H- d1 j1 r2 J' l, H8 |! `
set auto? false( S7 U# c6 Z* ~# n7 v* ?
set green-light-up? true$ h8 A/ x9 W9 Z. l- }/ B+ q2 {
set my-row -1$ ~9 R) G- {, A2 R, p2 ~5 S
set my-column -1 c( }2 E) ~) J" q& [
set my-phase -1
; |$ s3 t. A1 Z* b set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
, J5 x: _4 q4 k" t. F0 a& k7 v0 e4 l) @ set roads patches with
$ C; K% ]9 n& L" `" s [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" U% m: V. X& h5 p" C, ~ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 N9 r: k( w' {- R3 U- m set intersections roads with9 \! A5 s& d7 [/ L8 {% R6 @8 h8 C" g
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and- n2 O6 o& C, ^8 h9 M3 }+ ^ E
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 _; D. [ O$ r E8 L6 q* _: m
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ask roads [ set pcolor white ]
$ y& I; Z9 j) \3 Y" h setup-intersections- Z2 d; Y1 B9 F( u2 T& z
end% M% {) f3 o! m8 o& A N, k+ M* {
其中定义道路的句子,如下所示,是什么意思啊?
2 _8 q z$ g9 S set roads patches with
; A4 P T0 q( @5 W3 t [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 [. f, r/ H; ] (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
% I/ I1 ], U* K/ @1 u4 g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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