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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。
1 w W4 j# _" k& p4 A7 Vnetlogo自带的social science--traffic grid这一例子当中,
+ Q" S, F0 K- ~# f6 Z/ G$ hglobals8 Y' J- Q6 _9 W3 X7 r7 }1 s
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+ W3 t# v, Q# v+ f9 P w0 j grid-x-inc ;; the amount of patches in between two roads in the x direction
5 G$ W3 \3 R. Y grid-y-inc ;; the amount of patches in between two roads in the y direction% ?) v; u7 M" `' U2 w8 K7 v7 N
acceleration ;; the constant that controls how much a car speeds up or slows down by if
% p) K0 j+ \* q" j5 g ^4 } ;; it is to accelerate or decelerate4 B. A& a4 `7 U) F
phase ;; keeps track of the phase
" B; `) l6 Q% I5 K' Q num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure. p$ K* E" K* x0 b! P( a% C+ m7 [
current-light ;; the currently selected light
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( D1 }6 e. |* A: n ;; patch agentsets
M" U! N3 S: W intersections ;; agentset containing the patches that are intersections
- }8 H- t3 y6 s roads ;; agentset containing the patches that are roads
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turtles-own) |) i V/ O) ?! }9 k
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9 E& L4 k5 y" a- ^" I1 @" M speed ;; the speed of the turtle, |4 x2 ~/ ?- ]; O
up-car? ;; true if the turtle moves downwards and false if it moves to the right* j4 H* j& _ ~) B. k8 y( f Y
wait-time ;; the amount of time since the last time a turtle has moved
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7 S) |3 @ \, c1 m: ]. Z Ipatches-own
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intersection? ;; true if the patch is at the intersection of two roads
: r( F% Y8 u5 K) U5 D+ W! l green-light-up? ;; true if the green light is above the intersection. otherwise, false.4 |, O. R* `8 w% t' ]4 m
;; false for a non-intersection patches.5 S% t/ J7 X5 W9 r1 j- N C1 c
my-row ;; the row of the intersection counting from the upper left corner of the
! ~. _" b9 |0 o" T; i- Y5 H" T ;; world. -1 for non-intersection patches.7 ?* V7 g6 ?; q/ B6 T# L
my-column ;; the column of the intersection counting from the upper left corner of the+ a$ F* g/ x. @9 T
;; world. -1 for non-intersection patches.
. G: w o+ l: T R* [0 D my-phase ;; the phase for the intersection. -1 for non-intersection patches./ n# Z! `/ J; A7 J& a( v
auto? ;; whether or not this intersection will switch automatically., R1 c9 c2 ^; d- b. L1 j# g
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;. M6 \3 `+ `. B' I
;; Setup Procedures ;;
6 f, \. V, M$ @ \. J0 l9 T;;;;;;;;;;;;;;;;;;;;;;
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$ z4 y5 p5 v+ `/ J* O* X$ r- {! e;; Initialize the display by giving the global and patch variables initial values.5 j0 q+ V/ J# ]. h. g+ P2 h
;; Create num-cars of turtles if there are enough road patches for one turtle to; w' o' J% h& J5 U
;; be created per road patch. Set up the plots. ]) k6 I" h7 n0 D; U0 Q
to setup- Y6 d! E, X( ?
ca
: `, e+ B+ w1 n* c6 c, W* }) p setup-globals
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;; First we ask the patches to draw themselves and set up a few variables- n/ C; t6 c+ N$ Y) [
setup-patches$ W* `. j1 g5 ^4 ^- y. a4 c
make-current one-of intersections
4 n/ N( Z7 f+ `5 @" X! L7 x label-current
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set-default-shape turtles "car": E4 V0 u( ?& t: O% ^( `# X0 c) |
9 j0 v$ q$ g2 D4 P! j if (num-cars > count roads)
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0 f/ t2 W* z/ ?7 v5 n: x user-message (word "There are too many cars for the amount of "( x' b0 m. H" f8 a3 ?
"road. Either increase the amount of roads "
& i1 N* |4 c' z "by increasing the GRID-SIZE-X or "
P- H, e8 N9 w "GRID-SIZE-Y sliders, or decrease the "
8 r: t7 o8 a* c( D( T# K F "number of cars by lowering the NUMBER slider.\n"
8 f& X+ W1 Y/ s0 }2 S M9 } "The setup has stopped.")
. a* G" R* a1 X/ | stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
" [: I. V* K( L7 J# b9 ~' O4 x crt num-cars3 R) {" h& e1 s% m S: J
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& s9 p5 ^7 W7 s( E( H- Y _ setup-cars
% x* K: U9 N9 ^& v$ _/ X set-car-color+ D4 Y6 m6 W8 Z$ x( o' y
record-data- n$ g+ Q& C2 h* v- G
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$ C% S1 A: Y! S ;; give the turtles an initial speed* C' t* j: g# m( h
ask turtles [ set-car-speed ]3 Q8 L( ^; v: X M
" H5 a; n' W. t4 _2 M' K reset-ticks( c2 d8 }& X6 s, G+ f8 ~8 I& c1 Z
end/ O! l3 H! w' k" ] r5 S
5 Q8 o% w5 B7 |;; Initialize the global variables to appropriate values
& t/ y$ ~7 d& O4 r( X! mto setup-globals
+ W9 a k- ~+ l" h: @1 a set current-light nobody ;; just for now, since there are no lights yet/ I% |1 r8 f1 @ K3 W' [2 r0 b
set phase 0* W9 H% o* C' K& N
set num-cars-stopped 0) ?: X) l$ F7 z3 p, Q( R Z
set grid-x-inc world-width / grid-size-x
7 q5 X, b. K9 k% i2 j set grid-y-inc world-height / grid-size-y. Y3 u' @& S& l& j: i" A& k
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary4 r; l; R# u; u+ m3 E" O7 Y
set acceleration 0.0999 s: t1 I9 y& {, s1 u) f
end
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' d2 M- l$ S& n* p' `( K/ p;; Make the patches have appropriate colors, set up the roads and intersections agentsets,6 N9 d5 r* ?9 {5 b. n2 A
;; and initialize the traffic lights to one setting4 f+ ~: P3 i% B9 P6 N6 e
to setup-patches$ o# x( z- y: B1 L
;; initialize the patch-owned variables and color the patches to a base-color1 V! H% }. m% m( d
ask patches
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set intersection? false( H; i! H' \+ K7 Z: Y
set auto? false
( y% A5 o. B/ h set green-light-up? true
. _1 l3 a v7 `! T+ g set my-row -1
, i# \8 ~! a4 T set my-column -1
0 i; R7 w! @" H( y3 ^ set my-phase -1
) k6 c' v9 D$ `/ a; u- T8 m1 o set pcolor brown + 36 ~# \2 a7 l3 L9 a
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& N5 W( c. u G- {& D; f* o ;; initialize the global variables that hold patch agentsets
' V0 ^$ ~, c5 i% Z set roads patches with7 a' P( d5 i' D& ]0 s
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' e+ z/ t# v. E2 \( F3 q. c
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 Q; p; p# u) @2 X. I8 [ set intersections roads with
- Q) U) a6 O2 P. c# u s" F [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
- k& G7 H1 s/ L% _) ~4 [" u% m( C (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ] i( N3 j: h% [+ q
setup-intersections+ U$ a0 w4 t& N8 k
end" k1 i* P7 U% i/ ?& P
其中定义道路的句子,如下所示,是什么意思啊?9 M1 C1 m" k$ S
set roads patches with
- n7 S( r" b8 _7 k) P) O [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
; }: ~$ z9 }9 |/ Q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]" J( L1 {: @# U9 M% g @
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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