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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。
/ q, l9 v0 R" J# Z7 znetlogo自带的social science--traffic grid这一例子当中,
: Y0 v9 b2 O5 Z8 @' D: O2 Wglobals
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# r$ V& i1 T% `, M( T% _ grid-x-inc ;; the amount of patches in between two roads in the x direction
4 l; r2 @8 `2 ^) E% t grid-y-inc ;; the amount of patches in between two roads in the y direction
+ x8 o$ e5 t! l2 H acceleration ;; the constant that controls how much a car speeds up or slows down by if$ [* w* V3 j/ u1 V/ _
;; it is to accelerate or decelerate8 Y( ]) h% F, W
phase ;; keeps track of the phase( g$ c r" t) h, z% I
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
9 p$ U( N8 P w$ f current-light ;; the currently selected light+ W8 \# i3 l6 k* T+ [
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;; patch agentsets
* B- @' n0 r2 h. H, y/ Z intersections ;; agentset containing the patches that are intersections
9 A# d. x7 H# G1 j) s8 B roads ;; agentset containing the patches that are roads5 D" h2 m6 T5 V1 N& @: d# N. n; @
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turtles-own
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" u' _2 {4 W: p W6 D& d: Y speed ;; the speed of the turtle
8 C& M& _( E6 \. y up-car? ;; true if the turtle moves downwards and false if it moves to the right6 A) v S8 Q9 a0 c, {8 S
wait-time ;; the amount of time since the last time a turtle has moved
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+ ?: F& ~( J9 K0 G% y8 ^0 C2 tpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
( R; o! r- k( J7 Q& \* I green-light-up? ;; true if the green light is above the intersection. otherwise, false.
# Y: ^+ F: y- R! Z; c ;; false for a non-intersection patches.
, C6 B+ M# P+ S; @. { my-row ;; the row of the intersection counting from the upper left corner of the4 u8 {& j( ?4 z: N# Y
;; world. -1 for non-intersection patches.
, P$ h' L' {/ s% }. G my-column ;; the column of the intersection counting from the upper left corner of the
2 s& Y# X7 V; K8 w) |3 e ;; world. -1 for non-intersection patches.; U7 \. ]" u9 z: {5 }* ^/ W
my-phase ;; the phase for the intersection. -1 for non-intersection patches.6 P8 f1 @- |6 n6 P; v
auto? ;; whether or not this intersection will switch automatically.
/ {! v9 ]8 w1 d' T6 c4 h ;; false for non-intersection patches. Q4 b' l0 ^* G1 t: o
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;;;;;;;;;;;;;;;;;;;;;;
5 A6 R. e& t# J4 t;; Setup Procedures ;;
" q4 p& s6 B7 R/ o( b5 D( o p9 k;;;;;;;;;;;;;;;;;;;;;;8 | u3 ~2 H3 O( d: o' Z
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;; Initialize the display by giving the global and patch variables initial values.& M' v4 M! e h% I; @
;; Create num-cars of turtles if there are enough road patches for one turtle to0 H' B! i- N- l4 @. `; s
;; be created per road patch. Set up the plots.
% l# g( P5 Z7 `4 c8 _* Ito setup
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setup-globals# }$ v& |. w& ~
3 x* _1 o! Q6 e( b) r ;; First we ask the patches to draw themselves and set up a few variables
+ Y/ k. T" k, ~' U. l n: o setup-patches/ o% d; u3 L3 [, p- N& o! v
make-current one-of intersections
, W3 N5 ~' n3 Y# X* q5 _ label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)
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" M- w" i0 a* f1 G) M- o user-message (word "There are too many cars for the amount of "
+ o6 d3 N2 E) f5 w( ` "road. Either increase the amount of roads "
4 j! f0 Z4 P& Y! O "by increasing the GRID-SIZE-X or "
% B4 `8 a6 a2 z9 U `& e "GRID-SIZE-Y sliders, or decrease the "1 x: B0 }, b2 [' M: e2 L( f
"number of cars by lowering the NUMBER slider.\n"9 I! h5 n. t6 ]% N; ?
"The setup has stopped.")* @5 { g6 R* z7 K& m3 ^
stop
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/ f( t7 O5 s4 ~* J ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color& y) p" P. v: {
crt num-cars
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; p' Z1 x" m8 r/ }) D2 X* R setup-cars, j Z1 W! `; I& `
set-car-color) F( Y* C7 {8 |) h
record-data
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;; give the turtles an initial speed
9 `$ X9 l" u0 d5 u' {. f ask turtles [ set-car-speed ]
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Q5 L2 M1 H$ ~+ L! H; s- J reset-ticks
' e: D4 i b! F; z( {/ m x2 |end
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;; Initialize the global variables to appropriate values- n0 Y& L* b# s; j
to setup-globals6 {% |3 K' P; h+ s# U" n
set current-light nobody ;; just for now, since there are no lights yet
& v1 b( a$ G4 q; q, f) y! F5 u set phase 0
6 O$ y) N* R/ J* l! z" m! r% ~ set num-cars-stopped 0
: b) a3 X4 ^/ B8 b; C( r9 C& q set grid-x-inc world-width / grid-size-x% p5 M. I' k. d! \1 o. V: V2 i
set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary/ ^# L9 Q. p0 N9 Z; P7 k
set acceleration 0.099" v2 h2 q/ T( j* W- ~* B3 M f
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,2 O* ^, ?/ g* ~; K6 v' P F
;; and initialize the traffic lights to one setting0 g) U3 M- Z8 y. s3 @; F3 a* t5 p$ Z5 `
to setup-patches: M9 f0 I+ C6 D
;; initialize the patch-owned variables and color the patches to a base-color
; r( \4 J- r6 ? ask patches
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3 v- V, i$ F; T set intersection? false
; P. |8 i3 T0 G" p1 g5 A! h set auto? false
" J! P) j- ]) I! | set green-light-up? true$ T; |1 `: W! b8 x/ h
set my-row -1( |4 P3 q t4 P# s5 B1 G* D
set my-column -1" Y: D& T4 ?; o: E) R
set my-phase -1* \2 l" V F- f) {2 i+ f
set pcolor brown + 34 K( a! }8 y9 K* \, e
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: n. \! H w1 K3 E) M7 p, ` ;; initialize the global variables that hold patch agentsets
: U; x$ `+ O9 {0 I) s$ R" p! H( k set roads patches with
6 Q( v- {8 m( r( h [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# c! B2 `1 V( u6 o4 O7 Q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. B( U* t8 W# z& X; |- S- } set intersections roads with9 s$ x% i" N) O
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and5 n" p2 C: Q, K$ V6 \
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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) i0 X7 ^. U i ask roads [ set pcolor white ]
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end' v" O% f, @- N b6 B' y
其中定义道路的句子,如下所示,是什么意思啊? v8 @) Y* Q2 h
set roads patches with
* _) s( H: C/ B; X- h [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
( E1 {4 p! D% }! l) a: q. R! ]# ^ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 N4 E# |' A2 A% j0 |3 _
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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