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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。
: ^, V1 q. B9 r. Lnetlogo自带的social science--traffic grid这一例子当中,
/ V% |$ s) }0 E% ~globals" g9 |& c7 ?+ r& n2 o4 N+ `
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grid-x-inc ;; the amount of patches in between two roads in the x direction
( _- f6 p7 d" s L. C1 V; M. L' x grid-y-inc ;; the amount of patches in between two roads in the y direction/ d& C: C! Y1 X$ P7 \6 _0 m2 k
acceleration ;; the constant that controls how much a car speeds up or slows down by if8 R! j! p! X3 \
;; it is to accelerate or decelerate. k4 D/ h$ Q% V" R3 Q$ |: x
phase ;; keeps track of the phase4 [3 i# o, g- L n& P
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
2 ?+ w8 [) E/ b5 }! k current-light ;; the currently selected light' F9 m2 C9 K+ e: B, h$ ^
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;; patch agentsets% r N) ?1 d' G0 t
intersections ;; agentset containing the patches that are intersections
2 w0 L2 d* H4 d: F, E) g1 \ e roads ;; agentset containing the patches that are roads
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9 B) ^* u1 O! U- bturtles-own! f E- Q# q( P$ ?5 }
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speed ;; the speed of the turtle
/ K( A& Y+ O9 |- A up-car? ;; true if the turtle moves downwards and false if it moves to the right6 S9 r6 j% a8 h& \ `3 `# y. o7 S
wait-time ;; the amount of time since the last time a turtle has moved
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2 k9 n5 ]* n7 P! ]" f+ V: Fpatches-own! R3 x. R/ Y {1 _
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intersection? ;; true if the patch is at the intersection of two roads) [8 Z, O! Z/ Z8 @
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
8 v5 i9 n* l& Q3 V/ ?% ~ ;; false for a non-intersection patches.: C6 U$ `; J7 @; k' B
my-row ;; the row of the intersection counting from the upper left corner of the+ y1 S9 S2 k$ j: @" ]" X
;; world. -1 for non-intersection patches.
" T5 d6 X. m, f my-column ;; the column of the intersection counting from the upper left corner of the" r! G: Q% w& T2 e( Y# D
;; world. -1 for non-intersection patches.0 |9 T+ Z+ O7 b2 u$ `$ n1 W+ D
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
" G" a6 n0 Q/ y0 { auto? ;; whether or not this intersection will switch automatically.
2 H$ o1 q* [$ F/ S4 ~! g6 A ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
* ?! `2 e) \' v! K5 b {9 M;; Setup Procedures ;;& T4 U B) \* |. h0 y! [
;;;;;;;;;;;;;;;;;;;;;;
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- N* ^9 P) q }5 R, ?# U;; Initialize the display by giving the global and patch variables initial values.& m6 g. |: E3 k
;; Create num-cars of turtles if there are enough road patches for one turtle to
- I1 r/ t. r( [4 `' A;; be created per road patch. Set up the plots.) z' N0 s& i5 ?( Q8 V
to setup# F' U* @2 C9 X0 i, T
ca
8 e! x! c! I# l+ N6 K9 ]0 f setup-globals
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" S9 t( ^' p& H3 j, g2 g1 k ;; First we ask the patches to draw themselves and set up a few variables, ^' t p* j; R1 z
setup-patches1 e6 X, B) k X
make-current one-of intersections% ?3 Y% V# [* f8 B) w5 x
label-current
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7 ^& X8 {$ i b0 @# O$ f. f! p' r set-default-shape turtles "car"
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) E6 k* \/ c; |% L* s" e. ~( K if (num-cars > count roads)8 W" d/ \6 V l! I, t9 O, z
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user-message (word "There are too many cars for the amount of " m+ r" `" ]' R/ z- g: {
"road. Either increase the amount of roads "
3 x" K" T. k6 N/ n5 o0 S "by increasing the GRID-SIZE-X or "
& _3 h5 H/ R+ l/ I "GRID-SIZE-Y sliders, or decrease the ": b' [3 }& K3 ?- Y& R0 F
"number of cars by lowering the NUMBER slider.\n"
! s8 D$ h; F1 v( K4 y8 r* ?% ? "The setup has stopped.")
6 f- n9 b7 i9 S, R7 M$ b: r stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
& x8 t0 R& E t2 X crt num-cars# C0 r/ \/ m9 ]0 N z6 a: F* z
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setup-cars' V! i9 c, p* y9 [; W
set-car-color
2 [- R3 t6 d W. Y+ D: C; i record-data$ _2 P" v7 M4 a0 b* M. @
]
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# Q! `/ n, m* f) X ;; give the turtles an initial speed: C0 x( T! K9 a; O+ a! _
ask turtles [ set-car-speed ]
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reset-ticks
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;; Initialize the global variables to appropriate values& ?) I. T W8 Z" k& ~; K2 t7 c
to setup-globals( y" Y, ]. X' b
set current-light nobody ;; just for now, since there are no lights yet
3 i) c q8 p) c7 C* V) @ set phase 0
5 L$ D; R# q: C) v set num-cars-stopped 0
) C6 |5 ?+ i# m$ Z set grid-x-inc world-width / grid-size-x- c3 @8 A, e$ ^& }/ q
set grid-y-inc world-height / grid-size-y# n6 u4 E% E7 F+ c/ a1 l
5 s8 i" n* ]+ n ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary% t( h9 J" D; Z: f( E
set acceleration 0.099" C3 Q7 n+ q! \& A0 y; ]
end5 J: x" g2 \( I
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
1 C5 p! _6 `: P( u9 b4 x f, ~;; and initialize the traffic lights to one setting
F- j7 I z; f, Bto setup-patches
3 P# I; \9 N: Y# Q4 c ;; initialize the patch-owned variables and color the patches to a base-color0 w- }; G6 v' k& ^4 B
ask patches
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1 V5 F+ @5 E+ A! A3 m; u set intersection? false
; t: p/ }" n8 F V% g# X; R set auto? false
* ~! |. f+ Z1 }! B set green-light-up? true0 }- R2 m! C2 O, r
set my-row -1, J0 O2 C1 r0 {0 u9 Y2 R8 s
set my-column -1
! l9 g3 d( Z5 F1 `, W S3 @4 q1 t set my-phase -1
: K1 g9 Y) r1 |% q! ]6 [ set pcolor brown + 3/ V. u/ B/ z& F$ `+ o: M
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;; initialize the global variables that hold patch agentsets
: L5 J {! G2 r# n set roads patches with
9 V4 l9 }4 T8 S1 `/ a [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 ]; b! D7 }: ~" l5 u, O Z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 o0 l, d j4 g" W
set intersections roads with; ~" Z# f3 |% t. ^7 {3 V
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and# @" O& f" Z- w# w5 e
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ ^' b8 p4 N( B5 e' A6 O
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ask roads [ set pcolor white ]" a4 \* Y/ T- H1 Q3 u9 }
setup-intersections$ S+ q* \: P) g# K3 ]
end1 I0 I% N9 y" [
其中定义道路的句子,如下所示,是什么意思啊?
! h0 V" {5 d, v) c) T. T! U/ T set roads patches with
5 i+ n" W- q# {3 \/ g [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
O" Z! k+ t# w (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
' [. C% e9 G x% O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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