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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。
6 M, `9 p! _" {netlogo自带的social science--traffic grid这一例子当中,1 u; I$ f# k3 D2 @: z2 z
globals8 n" O" h4 X8 x! V' G1 j
[
) r- `2 j! J( }4 V; T grid-x-inc ;; the amount of patches in between two roads in the x direction
7 d8 ~1 ~! v$ m8 R6 Y1 X grid-y-inc ;; the amount of patches in between two roads in the y direction
+ U4 ]4 D* |* z* w0 o acceleration ;; the constant that controls how much a car speeds up or slows down by if
7 k9 b# e6 y' ?: X ;; it is to accelerate or decelerate3 K1 c3 H% m7 \$ v
phase ;; keeps track of the phase* a( s/ L# b. f5 g9 i5 A
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
$ E& R9 z9 \2 Q5 X current-light ;; the currently selected light |4 P8 i0 @* t" O! n
/ N1 Q# B1 J' R: z! L) J( P( U ;; patch agentsets
. j8 A' F; M; T; J, B3 ]: v4 D intersections ;; agentset containing the patches that are intersections
( X- r2 W+ e' z% `/ D. ^ roads ;; agentset containing the patches that are roads8 K; v9 q. {, {4 c( e9 u Y
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0 [& o3 ~- r6 J) z( q' @- ?+ }" vturtles-own
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& r3 o, @; x& r speed ;; the speed of the turtle
- c9 S& m* R, ^3 H8 I( D- Z up-car? ;; true if the turtle moves downwards and false if it moves to the right7 a& P* ]. w% X+ N: O: x" X
wait-time ;; the amount of time since the last time a turtle has moved- i$ h$ D' }: H$ c5 [
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patches-own* p* b* i! d! f5 i/ z) B
[
3 t6 m( |4 w) l5 S# l4 ^ intersection? ;; true if the patch is at the intersection of two roads
. e9 r6 V4 @+ z; ~ green-light-up? ;; true if the green light is above the intersection. otherwise, false.7 L' j. {6 S/ z* O7 ~* X/ B
;; false for a non-intersection patches.9 D% M, }. z$ @9 L( G1 S* d
my-row ;; the row of the intersection counting from the upper left corner of the
5 U5 |3 W* }. G ;; world. -1 for non-intersection patches.
9 H# g. S7 V2 F \1 O6 O* m" e my-column ;; the column of the intersection counting from the upper left corner of the
|7 b( m; Y# p ;; world. -1 for non-intersection patches./ h4 m5 Z4 A; [
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
- V, S) W. f! w$ ` auto? ;; whether or not this intersection will switch automatically.
8 I# G4 H) V6 I6 O! B6 ] ;; false for non-intersection patches.
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E- w9 b9 R7 U9 f;;;;;;;;;;;;;;;;;;;;;;
* H/ J1 ^! q6 G6 Y;; Setup Procedures ;;
% A* A1 D3 _6 l( \1 d$ z! I8 P( h% Q;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values. f% i: _8 x* o3 }+ y3 r
;; Create num-cars of turtles if there are enough road patches for one turtle to( J% @& g+ {. ?/ j9 k/ u! d2 j
;; be created per road patch. Set up the plots." D6 Z: x/ i# b5 ^4 e
to setup3 p/ L% h w) U1 M% L
ca* t+ q* q" X5 I4 K3 d: T
setup-globals }+ b: f/ G" T+ h6 R: {4 c
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;; First we ask the patches to draw themselves and set up a few variables
, r h; r+ X) T- J setup-patches
* U- c! m. T0 Y* X) Q8 P \7 { make-current one-of intersections
( f. l$ G" B1 Q0 d label-current
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4 m5 M9 I v. J* b8 x1 ] set-default-shape turtles "car"
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if (num-cars > count roads). L g( X; B8 f8 O" I; I
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user-message (word "There are too many cars for the amount of "
% {: {+ A" K, i$ k' i n1 ^/ x" u* d& U "road. Either increase the amount of roads "% h {2 r2 b7 ~+ y! B
"by increasing the GRID-SIZE-X or "6 m0 K: {+ o4 Y! Y: `5 `) i
"GRID-SIZE-Y sliders, or decrease the "
% |- N: `5 [) J/ w# a8 Q "number of cars by lowering the NUMBER slider.\n"
7 F. M+ F! G3 W/ o1 J* g) u. K1 K "The setup has stopped.")+ k; K) O8 R* E) j
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color0 M- b6 k+ }& m! }# y
crt num-cars) O, {/ D/ X8 C/ Q' R$ M9 M6 m
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setup-cars7 g& C4 O3 u' r+ o+ d
set-car-color
; \2 `- Q( {+ R; y) d record-data
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;; give the turtles an initial speed6 z7 Y7 m7 \' s
ask turtles [ set-car-speed ]5 G0 \# s' X. Q6 P4 F+ G; k
l+ ^% \. c! z9 ~/ I/ ]& u! Q reset-ticks
6 X g, `" E9 B, u2 Qend7 O5 y; Z0 L$ h; Q# B/ X
" F3 |5 S9 \) e; d7 W8 p;; Initialize the global variables to appropriate values+ P; w9 Q$ b" k
to setup-globals/ x: ?" A" ?3 l- D& o& A
set current-light nobody ;; just for now, since there are no lights yet0 D/ @4 O+ b1 [4 [/ l
set phase 0% i' X) B' P$ y' ~# k
set num-cars-stopped 0
& G2 I: O7 B1 n/ c; C: f set grid-x-inc world-width / grid-size-x
, ~9 g9 f) _$ g1 N& t U" _0 N& U! W set grid-y-inc world-height / grid-size-y9 w% a$ @& b, L0 _+ }0 E* c
" x, Y$ Q, t# v$ q9 l% {' \1 Y9 C9 Q
;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary* A3 F$ [# g% u6 a" I
set acceleration 0.099
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2 E6 s5 v: }- J1 C9 i;; Make the patches have appropriate colors, set up the roads and intersections agentsets,- F% b/ Q) F, C7 w- R; g
;; and initialize the traffic lights to one setting
- h3 @ Q- N7 K- L5 wto setup-patches
. D, q8 f9 @- q. P- L/ O' W6 P4 \ ;; initialize the patch-owned variables and color the patches to a base-color1 e( q1 `: M1 o% m
ask patches
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6 p$ K+ B# y" c; [9 r set intersection? false8 x, {5 b' |0 t; y" r: D2 u
set auto? false' @6 u: v! r) S, ^" _+ j- R' F8 d" c
set green-light-up? true
5 H* \+ I: \% A set my-row -1
- i$ M: Z8 C- g3 f6 h3 x set my-column -1! s8 n! S1 ?: S' v
set my-phase -1" x( V' C( i& m
set pcolor brown + 39 ?) T" s* T. R6 s9 r0 P
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3 [4 ?5 Z0 D' b8 W' {" ~4 W7 I& C5 {
;; initialize the global variables that hold patch agentsets
0 y3 j8 [: H |: U, [3 ` set roads patches with# u* T3 x/ A- M! |
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
$ W% K: I" [" `' g' j (floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ w$ s4 A5 X g/ G8 d
set intersections roads with7 @6 H6 d# y5 n8 K
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and* u4 o0 Q2 M+ U, x
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]% u' a0 ]- B* f+ e, C, I
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ask roads [ set pcolor white ]2 e+ Q5 h7 s6 v4 v2 }
setup-intersections( O. y4 [9 Q* x: ?" A5 g n
end% F5 y2 z( j+ V$ m( i" B9 M
其中定义道路的句子,如下所示,是什么意思啊?8 k. Y) _! C$ M. a$ k
set roads patches with
- q F Y! w7 H o2 t2 ]: ?) ? [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
8 h) ^7 V% c5 z6 K2 n) W( w (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ b7 X) G! L y5 _/ K% f! N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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