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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。
2 ~' f3 y$ _6 c" l9 Hnetlogo自带的social science--traffic grid这一例子当中,7 K7 b! ~. v; U
globals+ m& K8 ]' z* e
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grid-x-inc ;; the amount of patches in between two roads in the x direction1 y. i# B4 r f& n
grid-y-inc ;; the amount of patches in between two roads in the y direction4 s. B& k: E6 L, d. [" G8 [% b5 [) s
acceleration ;; the constant that controls how much a car speeds up or slows down by if& B% G& e- }# U: d: @6 h
;; it is to accelerate or decelerate, A: m8 w2 X5 S. N* T; j
phase ;; keeps track of the phase
- s$ D' }8 r6 @! G( R; P num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
0 ?7 ^9 [& ^5 v current-light ;; the currently selected light
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;; patch agentsets
: ~& G6 }6 G/ F intersections ;; agentset containing the patches that are intersections, m+ n) k* ]4 |
roads ;; agentset containing the patches that are roads
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turtles-own
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7 o% J" m, s3 }+ i5 H( K speed ;; the speed of the turtle( h$ b" P9 ^9 n6 l4 b- i* d
up-car? ;; true if the turtle moves downwards and false if it moves to the right6 g* c. H7 D/ F) ~$ n
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own* Y0 P, l5 R" }) g, |* ]6 \7 k% C
[
+ y) N$ ]3 D" n# |/ M$ g' W intersection? ;; true if the patch is at the intersection of two roads8 j9 V7 ]5 L! |+ ?
green-light-up? ;; true if the green light is above the intersection. otherwise, false.5 A0 F z m4 A2 L! e
;; false for a non-intersection patches.
9 s2 k% W2 Y( n6 K. a% K. H2 ` my-row ;; the row of the intersection counting from the upper left corner of the
, K; l: e6 u% k2 b9 t ;; world. -1 for non-intersection patches.
. ?# |& w, a( y my-column ;; the column of the intersection counting from the upper left corner of the1 ] u, ]7 y z4 R$ X: d% T4 ^
;; world. -1 for non-intersection patches.
( d8 B' e7 ?% y' f. h; R/ m4 V! } my-phase ;; the phase for the intersection. -1 for non-intersection patches.
. P) f. B1 `" q6 q' P2 ?2 i# }% u auto? ;; whether or not this intersection will switch automatically.
: w9 E' o& z: X" | ;; false for non-intersection patches.( ^9 }4 ?2 F8 g* t8 s4 Z* Y
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;;;;;;;;;;;;;;;;;;;;;;- r) |8 }7 Q1 |8 L( h3 p p
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.0 |/ `, V1 H# _! K) q0 p4 v
;; Create num-cars of turtles if there are enough road patches for one turtle to9 b, v0 V: z* m2 J/ J. T0 y5 }
;; be created per road patch. Set up the plots.# n7 B9 Z2 p4 A
to setup( u0 e8 N3 r7 S* H; O5 I' [4 F9 _
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setup-globals! f: I' b0 J2 N
" I; @+ m2 B% F, y. O8 O @) I# | ;; First we ask the patches to draw themselves and set up a few variables' Z7 r4 @6 V$ t, P6 d& e% h
setup-patches/ ^# w6 x# f. y
make-current one-of intersections
% e0 i j8 @8 r5 ?9 f" R label-current
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# y# e; w2 k7 u. s( \. d. t set-default-shape turtles "car"" z' I0 w0 ~( C" Y5 m& w
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if (num-cars > count roads)
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+ E$ E% z7 w! G1 u% s2 u7 d user-message (word "There are too many cars for the amount of "
7 f- p$ ?7 b4 F4 g4 r: w "road. Either increase the amount of roads "! r( U1 L# I v
"by increasing the GRID-SIZE-X or "
& F$ c" q- x' ^8 l9 V- q "GRID-SIZE-Y sliders, or decrease the "
4 T4 b5 R' c+ m7 A" C7 Q! k "number of cars by lowering the NUMBER slider.\n"4 P& M: i, W9 |9 q/ p5 c: n' r p
"The setup has stopped.")
! v; r2 I" ^ v5 `* J8 _ stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
7 k" k2 W; D1 ? crt num-cars; L) A; H: B) Y* z6 T- t, o, V
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setup-cars
; f* w) }+ V' p: l set-car-color: O, Y: S/ w6 Q9 f, x ~
record-data; G# c l$ A+ v2 A$ K7 F8 _3 ^: |
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2 x( I, s- e7 \7 F9 W0 ~* K6 L" [ ;; give the turtles an initial speed
0 ]* F! r' _2 ?5 @! z2 Z& a8 L ask turtles [ set-car-speed ]6 S4 M2 P. S N/ R
5 |* b( J3 `3 h, m" C6 p reset-ticks
3 V4 p- ~0 O9 gend
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;; Initialize the global variables to appropriate values
8 y7 T7 v! v* Y: _to setup-globals
. ~6 J/ y( K$ g! X: C set current-light nobody ;; just for now, since there are no lights yet
5 l5 T/ \: s( Z k: z# B set phase 0" W- x$ B7 x( e
set num-cars-stopped 0
; n: `3 X# O& h+ c+ K$ J; P set grid-x-inc world-width / grid-size-x
6 ]; g& V; n6 v. ]' m set grid-y-inc world-height / grid-size-y# b+ r) O: [* i" I$ h, Z4 r
4 Y; O: \& N9 m ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary5 Y: [6 w1 ?3 i7 s" l; h+ ^
set acceleration 0.099$ z- u: E+ d0 _' x: t
end( z8 Y. N6 C6 @. L
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
. _8 x. h6 A, {;; and initialize the traffic lights to one setting
5 G6 a3 _) O3 R. N* D+ Kto setup-patches' c) z8 ^6 R r
;; initialize the patch-owned variables and color the patches to a base-color- w0 q" u' e& y- [
ask patches
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set intersection? false
) m; e0 C5 E8 T% p* }! Z/ N set auto? false' j. x9 z+ @$ u% k' e8 x# e
set green-light-up? true
0 O# e% D3 ?' o& A set my-row -1$ w2 B0 Y* h4 g# J; q
set my-column -1
. z1 `# k9 Q3 ^& j set my-phase -1; i- j4 E, J0 b
set pcolor brown + 3
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! ^& S: ?# P C% k# v ;; initialize the global variables that hold patch agentsets
7 W$ I6 o; u9 k; J. U8 S: `$ V/ h set roads patches with
, e, e! t3 ^) t- L0 Z7 m, U- B# K [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 M! ?, D) W+ ^6 ]9 l (floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 Q0 D6 u* e0 b; n S- |
set intersections roads with
$ c* Q' @, j0 g& w [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
" O. A$ W+ _ |1 ?* F3 [8 K (floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 A8 F, D' O: s. p- S
& } M5 V# k5 _+ P2 u ask roads [ set pcolor white ]
7 i9 f9 t7 Q$ K6 t9 m/ h setup-intersections
0 I' P) l* X* r. \6 P' Z5 E& }end
( I8 J& W2 n6 d! m* i其中定义道路的句子,如下所示,是什么意思啊?( N/ T- k0 F; x
set roads patches with
( d2 [5 z9 _' H2 i7 Y [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
9 u! U V& u6 R (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* a& T3 L( m3 z4 _3 R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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