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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。; s& P9 b( W, Q
netlogo自带的social science--traffic grid这一例子当中,
R* e0 `2 Q! w t; z" |globals
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, o% |7 `; c& J: k. z; L$ { grid-x-inc ;; the amount of patches in between two roads in the x direction
1 P9 e0 p" ?8 s3 _& ]" N7 M grid-y-inc ;; the amount of patches in between two roads in the y direction
; a9 ^* i: I+ t, P" R5 \ acceleration ;; the constant that controls how much a car speeds up or slows down by if* o6 I: v: K3 T
;; it is to accelerate or decelerate
?6 d7 t% ?1 a* J. Z phase ;; keeps track of the phase
+ k5 `# F8 o0 U. k7 _ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure) W4 s; Q4 ]$ O8 w3 t8 }
current-light ;; the currently selected light
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;; patch agentsets
: M" b' i6 O u* G$ l intersections ;; agentset containing the patches that are intersections
" @$ f% o) D: c+ n' J1 q8 X- ? roads ;; agentset containing the patches that are roads: g1 V1 s: \2 V- o4 I- b
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turtles-own
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speed ;; the speed of the turtle
9 F) @" R0 W: o0 P' S( h8 P, Z up-car? ;; true if the turtle moves downwards and false if it moves to the right' p$ A; u" T& E: y, Z
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
5 T; O# m$ Y; X' B9 \ z green-light-up? ;; true if the green light is above the intersection. otherwise, false.
) F4 ]9 P7 L3 u6 ]9 i ;; false for a non-intersection patches.
0 \* _* e7 Z) y my-row ;; the row of the intersection counting from the upper left corner of the* Q4 U. K+ a6 l
;; world. -1 for non-intersection patches.
+ q k! A% d! I8 ~ my-column ;; the column of the intersection counting from the upper left corner of the- M! s# R0 \ t
;; world. -1 for non-intersection patches.
/ ~6 U7 `! h2 H @1 c' V my-phase ;; the phase for the intersection. -1 for non-intersection patches.
; M% ]0 M. [- z9 M auto? ;; whether or not this intersection will switch automatically.
Y' g: B/ ]/ g5 j% } ;; false for non-intersection patches.7 X# o0 v, x5 J! J) H# }8 W: u- p
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0 S5 a$ U/ `) p$ P3 O9 `1 e k+ z: |/ K;;;;;;;;;;;;;;;;;;;;;;$ S( e {! u' \% C- O/ m7 I
;; Setup Procedures ;;
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$ \; c [0 _" w# G! F;; Initialize the display by giving the global and patch variables initial values.
& \9 ?7 o# x: P5 K7 ~3 z6 g* ]; c0 K;; Create num-cars of turtles if there are enough road patches for one turtle to
0 n2 ]6 [" G0 c- q/ i5 P;; be created per road patch. Set up the plots.
; x4 [' `3 h* X( C0 W! O/ I( F7 ato setup
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% I& A5 }* T7 _% q. ^/ I setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
1 C b W- f* @, M setup-patches
& y* N7 G/ }/ z% I8 B4 B7 z make-current one-of intersections) Y, R7 r* {6 r& ^% C
label-current
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% X* u" ]* Y# I0 v set-default-shape turtles "car"5 U& V% I: p. e
_) L: l* t4 h3 |1 G if (num-cars > count roads)' I, S' @; U0 V" [1 e) o3 u
[
, ?5 w1 e6 U5 F- }4 a2 Q user-message (word "There are too many cars for the amount of "5 }* O7 k' E& x2 a& q6 |7 ~$ ?
"road. Either increase the amount of roads "
' j6 N4 E* F! t( R) Y2 R "by increasing the GRID-SIZE-X or "
" m, Q: d2 l$ `2 U9 C- w "GRID-SIZE-Y sliders, or decrease the "
, z0 ?6 W2 x& a, r& g, c* A "number of cars by lowering the NUMBER slider.\n"6 g" R" V0 w2 a% G/ y
"The setup has stopped.")0 { M: d6 Q! P4 D; Z& c
stop4 M P: T2 _/ l& c
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! \: n/ _# Z0 j* b* ]2 h ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color/ t, Z X. M+ g
crt num-cars
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setup-cars5 ?* D1 a! r6 Z5 ~& H+ ^9 m$ Q
set-car-color
' n2 x- |2 P E$ l2 ^ record-data
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;; give the turtles an initial speed
6 ^/ R- e. ~' N ask turtles [ set-car-speed ]
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* u" F7 r! _5 O% k4 Z4 E. O reset-ticks2 N0 \* a1 Y' o) l; \
end5 b2 H/ r. a/ h# `- V2 z8 G# t
! V# ^0 J7 J2 S. _, [% r+ ?3 W;; Initialize the global variables to appropriate values# u; x5 j3 y3 G7 i; X
to setup-globals; R& }. c5 m+ f7 E
set current-light nobody ;; just for now, since there are no lights yet' y, `2 s" q6 X- H) F4 C# m: |& p
set phase 0
/ f! s1 p% P' f. c; x" W set num-cars-stopped 0
2 \1 s8 r/ E, C/ L) V! ? set grid-x-inc world-width / grid-size-x* Y6 Q k( x( n+ z& R2 R
set grid-y-inc world-height / grid-size-y2 T' o4 N( x; P9 }+ X
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
, j8 n1 h1 W5 _: v! \ set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,$ S, B) I. B0 o e; a/ `4 L
;; and initialize the traffic lights to one setting9 Q- [2 J7 [2 M9 Z8 F9 l" t, c
to setup-patches
% G' Z- {& n8 v/ ?. M ;; initialize the patch-owned variables and color the patches to a base-color9 p! f* v% ~% l. M/ N. u) r; @
ask patches
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set intersection? false
7 q; {6 B3 |- N' G7 e& L' @! M2 T$ B1 E set auto? false
, Y3 u9 `: F; ~4 J5 M; G' Q) p set green-light-up? true
- z& O# R' d3 h: ]4 C set my-row -1
/ S& K6 K6 R# Y$ { set my-column -19 [/ K8 u3 `# J9 m. n5 B8 e
set my-phase -19 c( G# d1 s. Z( k5 e
set pcolor brown + 3
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0 u4 o; u' b' r ;; initialize the global variables that hold patch agentsets
& b" n$ Y8 T# a- ~3 z set roads patches with
! _3 g' x/ _- u1 Y+ t [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 J% G8 H% A: G! \' t* }) T (floor((pycor + max-pycor) mod grid-y-inc) = 0)]# |9 k4 `; Z! s) y$ A
set intersections roads with
7 \6 ]- I# Y( [( U [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
, _4 z6 q- |. ^: l+ D: b. I (floor((pycor + max-pycor) mod grid-y-inc) = 0)]( |$ B9 c# w. n" [
5 K( {1 X8 R! c ask roads [ set pcolor white ]6 Z3 L' h+ S/ {& k1 ` h
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?7 S% b& R+ K) V3 u' Q% n7 M
set roads patches with
1 ^2 m' ~9 w) {4 H [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or* e8 t; n0 M H( L
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
& ~; X6 I+ a7 d3 _, ?# K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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