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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。( _+ J* s, _! a
netlogo自带的social science--traffic grid这一例子当中,
9 `2 j6 n# ]1 y* z8 Nglobals b; }' f |) R* ]% Y1 D* g
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& B8 l8 m U" N8 \ J1 d grid-x-inc ;; the amount of patches in between two roads in the x direction
* J, V3 V+ T* d1 C+ x% E& u grid-y-inc ;; the amount of patches in between two roads in the y direction6 p* S1 o% F/ |% y6 `8 C# Q `, F3 z
acceleration ;; the constant that controls how much a car speeds up or slows down by if
* S% U9 u5 w! {+ D; a$ A ;; it is to accelerate or decelerate5 j+ h" M2 r s6 o( ~
phase ;; keeps track of the phase( f2 o7 _% i& z! I" w; }
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure" N: Y6 j5 \+ V: t6 b
current-light ;; the currently selected light3 V( U* O% f, K+ y M
( l Q2 c( M' r7 L3 d' d# U: O* I ;; patch agentsets
' f% G9 ]8 h3 c- E5 i0 F G intersections ;; agentset containing the patches that are intersections" C2 u6 l% Y# [' o7 _ @+ ~
roads ;; agentset containing the patches that are roads @8 \4 n% y6 S) }* j6 T
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turtles-own
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7 A2 X( v3 o0 u* J9 y) L9 T speed ;; the speed of the turtle
- J0 Y$ Y- R9 y4 B$ A) }* w" `( Z! w up-car? ;; true if the turtle moves downwards and false if it moves to the right" F3 C ~! L; y# x
wait-time ;; the amount of time since the last time a turtle has moved# [- d N7 w+ Q- p+ S, x
]
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7 |+ m% n3 R ^1 Z1 Xpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
) ? O" q: D f4 |1 V3 j- z green-light-up? ;; true if the green light is above the intersection. otherwise, false., Z/ t5 c) U* t
;; false for a non-intersection patches.% U9 f4 k! C# r3 _3 P% t# t
my-row ;; the row of the intersection counting from the upper left corner of the
# H1 @ L0 |% l2 B4 c" t% J/ W ;; world. -1 for non-intersection patches.
- l/ U2 V- q/ _ W% I4 e my-column ;; the column of the intersection counting from the upper left corner of the
e8 q" q1 r% g9 P# z ;; world. -1 for non-intersection patches." q+ a# U3 _+ V& {5 b. g( D5 ^' M& v
my-phase ;; the phase for the intersection. -1 for non-intersection patches.. \# Z: |: P/ a& C* F T4 Q- _
auto? ;; whether or not this intersection will switch automatically.4 i( p4 J. y0 P% |; B8 P
;; false for non-intersection patches.
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0 v- g2 J% E# p* K2 \! T* z;;;;;;;;;;;;;;;;;;;;;;
5 Z' o/ z8 G1 D- e;; Setup Procedures ;;/ X) Z8 m3 n0 H2 e5 M+ S1 |1 d
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
# x' B. _/ O( r: s5 b' l2 T" h;; Create num-cars of turtles if there are enough road patches for one turtle to+ @+ d* \5 @/ E( G
;; be created per road patch. Set up the plots.
/ i8 R& v& x9 z* _$ `) ^to setup
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* o! G/ U/ o0 J8 ], O) F2 | setup-globals7 I, c- `$ C) g$ o
5 Y8 v4 N( e) M5 U ;; First we ask the patches to draw themselves and set up a few variables: {7 B1 h9 S1 y# Z% Q, K# Q
setup-patches5 ]0 s( N, \! Q
make-current one-of intersections; u; J: P$ B' g
label-current
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% Q3 h2 _/ V( o- Q set-default-shape turtles "car"
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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 "! m: A4 N. F8 j; |) F
"road. Either increase the amount of roads "% _, p) W, P2 @/ ~& F
"by increasing the GRID-SIZE-X or "
4 b: g; W& Z* g9 o. I- |. o "GRID-SIZE-Y sliders, or decrease the "
" s4 L) t) N6 Q3 J: n "number of cars by lowering the NUMBER slider.\n"
- ~7 d1 H7 {- ]3 s5 Y% o. d "The setup has stopped.")
- c3 M5 l! M' V4 x stop
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) H* t% H" ~ p0 }7 @8 h ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
3 t6 `. f* K6 R6 \! u6 | crt num-cars
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setup-cars
/ E$ L6 P+ F: h; Q1 A* i2 w set-car-color
: K: I0 h6 |. l% r+ Z- O record-data
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;; give the turtles an initial speed
0 k8 r4 N% G' |8 Q# n( u* _9 f ask turtles [ set-car-speed ]
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reset-ticks1 v' t! A! ?! H* d& e5 R3 n
end2 [4 S. }5 D6 u- r* x5 j
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;; Initialize the global variables to appropriate values
# F" W0 x" i' J* C- Fto setup-globals
( @+ `. J y; P0 _' D- @' w( h set current-light nobody ;; just for now, since there are no lights yet
1 @$ y$ l. {1 j2 V$ L set phase 0$ e1 {, l% d+ g: q
set num-cars-stopped 0
* ~0 K0 Q+ L# W) l$ I set grid-x-inc world-width / grid-size-x! |+ [! S- w7 u. E2 W
set grid-y-inc world-height / grid-size-y2 s3 B0 [9 X0 ]1 N
) s- Z5 r; }: `( i4 q% V ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
; G# m* D3 ?9 U( D5 x set acceleration 0.099' g# W7 e+ k* V& }
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,7 z" T8 O' \! _/ f/ R2 o
;; and initialize the traffic lights to one setting: R9 C- V+ Z4 E/ o3 R
to setup-patches
2 _" Y% m [6 G* q" g3 c# Y ;; initialize the patch-owned variables and color the patches to a base-color8 {8 m* q& e) v7 O( @
ask patches
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8 l2 `1 o3 f6 ~6 Q+ e* [ set intersection? false( B, V \: K3 T
set auto? false
" {0 q& y+ b2 Q0 F" x+ I1 R; E set green-light-up? true
4 s" ^2 s3 q" O; {/ m4 i set my-row -1
7 \( B& d& x" Z0 X, ~ set my-column -1
2 P' j2 ^% z, r% i set my-phase -1, B; E' J$ e4 `' p' y# i
set pcolor brown + 3. A" w" ?4 I- Q9 x
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; i1 U; _" {9 t8 `1 c' o ;; initialize the global variables that hold patch agentsets+ Y! t( q- x5 G, O; j
set roads patches with+ s4 }2 `' r: c
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
- A1 B3 T/ [5 r" v/ H (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
% _7 G' r5 C! W set intersections roads with
3 m8 I1 T3 R' V7 ~. ^: s" @ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
% |: Z M; M& P2 v' t4 R: ` (floor((pycor + max-pycor) mod grid-y-inc) = 0)], P5 z; c1 }1 V$ u9 b$ K( t" j
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ask roads [ set pcolor white ]1 M0 d6 q5 V6 o, S
setup-intersections
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. q0 a5 r* ~: ?9 J6 z2 C) \& b其中定义道路的句子,如下所示,是什么意思啊?4 j! k4 x) G8 Z% L7 c
set roads patches with0 h: w. [! B4 j# S( B- Z
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: B5 H2 D! h$ S- q( i (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
, P( o% o) m1 k. k7 _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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