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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- U) [: k' N% {. U8 @4 unetlogo自带的social science--traffic grid这一例子当中,* H0 {: f* Y" o- A
globals! C: ^1 M5 `5 ?
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grid-x-inc ;; the amount of patches in between two roads in the x direction
" d& v0 b1 V/ @; \ grid-y-inc ;; the amount of patches in between two roads in the y direction$ k9 s3 @6 Y) H: K3 N1 |- L
acceleration ;; the constant that controls how much a car speeds up or slows down by if
& ~9 u+ A9 H, h; y: S3 D; e- X' j. U ;; it is to accelerate or decelerate
- A0 V# }1 ~3 C% q$ c phase ;; keeps track of the phase
6 M9 W; l# [# k num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
4 y7 n% H/ w, F) c- ` Z current-light ;; the currently selected light9 b' o- c9 z1 V6 n b- C- Q
3 J5 {" _. [9 P& p: v5 g& Z, O f ;; patch agentsets
, x9 L& |, W |' L' r intersections ;; agentset containing the patches that are intersections& v/ l& A1 L6 @' W3 z
roads ;; agentset containing the patches that are roads
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! z5 c, K# }2 K! Kturtles-own% W- l. P p5 p6 t1 v
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5 `2 z; C Q- N speed ;; the speed of the turtle
: `- e4 `5 z# y6 H! }+ w up-car? ;; true if the turtle moves downwards and false if it moves to the right4 }7 \% I# k2 x6 Z: L2 c. v
wait-time ;; the amount of time since the last time a turtle has moved# \+ l- T9 U5 F- p
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5 ~: w1 O, C2 u" `6 g& p' dpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
9 R6 ]" l8 t6 G. W% {0 V8 N green-light-up? ;; true if the green light is above the intersection. otherwise, false.
, s/ O8 z5 z: i0 m5 K! g# x" n ;; false for a non-intersection patches.
8 X% ?8 ]9 T0 ?7 _, G my-row ;; the row of the intersection counting from the upper left corner of the, b5 h7 R& I3 `. M0 b5 d
;; world. -1 for non-intersection patches.3 z" l1 ^/ u- ?2 w6 S
my-column ;; the column of the intersection counting from the upper left corner of the/ m+ Q& Q' s( D- `% h" I% {) P
;; world. -1 for non-intersection patches.
& m0 C0 Z1 l" E5 x, d. V my-phase ;; the phase for the intersection. -1 for non-intersection patches.
9 u G5 `, n- w1 f* J, Z& p t auto? ;; whether or not this intersection will switch automatically.
4 |* d. U! O) Q; G/ p ;; false for non-intersection patches.8 D+ X+ Z" e" |. T( x
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' e( F B- U/ I: P" y$ K" x$ Z;;;;;;;;;;;;;;;;;;;;;;
6 h; o. [) R/ i) A9 V, K;; Setup Procedures ;;
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% w* |' n, O* O' ~;; Initialize the display by giving the global and patch variables initial values.3 j1 G6 [7 \* i4 O
;; Create num-cars of turtles if there are enough road patches for one turtle to3 ]' F# r1 |2 h6 I. k
;; be created per road patch. Set up the plots.& p- s. v/ ?% W9 W% `, T- X
to setup; r! \3 Q6 k; j1 T# F9 h: C
ca
4 u5 N* `! w, c6 Y5 F, ? setup-globals8 @7 Z7 m7 w; W
( @- I/ e: W. Y2 c/ ?/ H. } a ;; First we ask the patches to draw themselves and set up a few variables
: }6 j/ O6 ^* }# y5 @+ n, l setup-patches
" q3 z/ ?4 w' F$ C5 e! F& p5 H make-current one-of intersections
6 R6 H- U$ R2 z label-current# e: `9 u+ \4 o
- v+ L: a) T! Q: \$ O* m set-default-shape turtles "car"
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) b( b4 X- A$ n4 k2 A3 N5 G0 p( P. d0 S if (num-cars > count roads)9 H6 _/ N) E6 \( N9 k
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0 |. A1 h- B4 r& h' [/ _ user-message (word "There are too many cars for the amount of ", y: n/ |! n" b6 O7 `
"road. Either increase the amount of roads "9 e, G# {0 H; l) A
"by increasing the GRID-SIZE-X or "
' F3 [; b/ z8 O! Q% S "GRID-SIZE-Y sliders, or decrease the "
7 R; h5 v, Z9 Y" X "number of cars by lowering the NUMBER slider.\n"/ ?) r$ |- X& p1 L
"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, x" {( R. U% w) U. V. K8 v
crt num-cars2 a2 Q& f# ~' v1 B
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setup-cars) d* f( c! d1 A* y7 V' z
set-car-color
2 j% O# J6 Y% [, r/ w record-data
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6 Q" q' m# {' ?8 J# E( E+ o- T ;; give the turtles an initial speed# A0 A: ?& m9 M
ask turtles [ set-car-speed ]
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+ K: s- k2 j6 g" ]1 W; j4 }3 F reset-ticks" D/ W0 t, y/ j
end
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$ t* H4 R$ s. @6 V;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
+ F8 W1 _& _- m% e! e: I+ X set phase 0
3 [4 {+ T4 t1 @& j set num-cars-stopped 0
% l; H3 Y1 O5 P set grid-x-inc world-width / grid-size-x \8 D1 W9 a6 Z/ s% n2 y/ C" n
set grid-y-inc world-height / grid-size-y1 u* y5 c g9 E, a' }. x
8 F! }: T: S) U' j- L ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary% c" m) O+ i. t$ Q1 E
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,1 s7 x7 v0 s/ }" O
;; and initialize the traffic lights to one setting+ y& b5 S/ K" ^ H' t t* Y/ f
to setup-patches6 `1 E3 A8 Z `6 [% x
;; initialize the patch-owned variables and color the patches to a base-color1 b, y1 ]/ W. }8 E
ask patches. x$ G8 g$ ]2 l* y \9 q3 r
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set intersection? false
; q1 W0 o& |- s' U2 T+ K" I* h. k( q% n set auto? false
* G( Q' x- T) V8 {6 D6 k9 R: a set green-light-up? true4 w# f* O" F; G ]! o
set my-row -1
6 y/ @5 c# P/ t0 S' I# R set my-column -1
9 B) |/ I0 x$ D# |7 w: z set my-phase -1
, M9 {& o' D3 f ? set pcolor brown + 3& f" o& i% ]5 K' v( z- \8 [
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6 ?3 e) N$ \- k* o4 [5 n ;; initialize the global variables that hold patch agentsets
' n: ^ I8 w8 ]9 o) K' n; Q3 K set roads patches with! }5 o8 ^ \8 C9 u7 @+ W6 l, |) s
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" H7 a& j4 F. z1 ~! w (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 W$ o& \3 k$ V6 r \: p- K% k set intersections roads with
7 V0 ?6 y. H7 k: J3 {2 n [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
6 v, y6 B7 Y9 {/ N% T! O (floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 q ~& G) Q/ I: A
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ask roads [ set pcolor white ]. n) y2 ^* O/ i1 q& [8 u$ W8 u
setup-intersections8 Q1 `5 o& k7 u6 u+ |$ g! E/ D
end, f" Y8 e$ m% R: D% U6 ?
其中定义道路的句子,如下所示,是什么意思啊?8 E5 ]0 D) P' S/ J
set roads patches with
7 ^1 c* I# K' D2 R! B& }& i$ L( G% W [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" U& h# [' ?. b" K7 @
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 y( r! G9 l# k# a
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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