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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。
# T- R' E7 x. l0 ?netlogo自带的social science--traffic grid这一例子当中,- b& Q8 y5 Y; h. q4 O$ J
globals
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8 l6 j# W* r6 ] grid-x-inc ;; the amount of patches in between two roads in the x direction
- ]1 ]7 b+ [$ p n. }0 `- W2 [& y grid-y-inc ;; the amount of patches in between two roads in the y direction
. B3 W& Q+ \. F acceleration ;; the constant that controls how much a car speeds up or slows down by if7 C* F; R: R2 V. l! R
;; it is to accelerate or decelerate7 g2 T1 x( w" `8 _
phase ;; keeps track of the phase& @! [" }3 h: L5 t* t- ~2 o
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
$ S% q" Q5 b" x% o) R$ P/ n, J current-light ;; the currently selected light2 P6 s- U2 r, z$ K: l
* g, Y; R; M g) U) ? ;; patch agentsets$ y$ H, e8 z8 e. I' q1 m$ l T
intersections ;; agentset containing the patches that are intersections
% s! U, U6 B) @. V) `$ D; v2 ] roads ;; agentset containing the patches that are roads7 n1 G& B J6 A/ f! S4 _5 `
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turtles-own3 T2 h7 e% C; `- Z: }& n
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$ D1 ]) m2 i# {0 Z' `7 T5 v speed ;; the speed of the turtle
+ e d' X z' c7 g) @& [' a up-car? ;; true if the turtle moves downwards and false if it moves to the right
" o' Z" ?$ r/ z1 g, T: G7 ? wait-time ;; the amount of time since the last time a turtle has moved) ~0 C3 T6 d3 Q" S. |* g R2 @
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patches-own
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8 B) s5 T) A. n6 _% _. M l p& ? intersection? ;; true if the patch is at the intersection of two roads! i) F% I# T7 V M
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
9 A. U+ i' o. } ;; false for a non-intersection patches.1 J/ M' p. H5 h# e5 s2 o
my-row ;; the row of the intersection counting from the upper left corner of the
0 @& N9 f" f" @4 M' M ;; world. -1 for non-intersection patches.
) e. O* w; h) v% I- e8 A+ x0 } my-column ;; the column of the intersection counting from the upper left corner of the* G' A7 m. A, O
;; world. -1 for non-intersection patches.
/ u) d* ^5 i3 K9 u Q my-phase ;; the phase for the intersection. -1 for non-intersection patches.6 \: v0 v# m, k2 j7 h
auto? ;; whether or not this intersection will switch automatically.
) s @7 l# P6 F( h/ `4 o( o6 c ;; false for non-intersection patches.
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, ^+ \" a, h g* X% I5 n6 J;;;;;;;;;;;;;;;;;;;;;;
0 q) @0 p6 |, K- _;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
# n+ c- B$ \9 D" \;; Create num-cars of turtles if there are enough road patches for one turtle to
8 B7 k; V/ S' L8 D7 d/ j& E;; be created per road patch. Set up the plots.
$ { Z. [" P# h9 }2 K' z$ `to setup
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* J$ k( [: z' s3 [3 D* J" n6 z G setup-globals
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;; First we ask the patches to draw themselves and set up a few variables' s4 c! X! J, r" M( k
setup-patches
6 C9 @3 s% g* ^# E make-current one-of intersections
8 d% O, K5 l" D) }9 l label-current
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; G- ~! ^1 _0 ^5 I set-default-shape turtles "car"
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4 F& b* _6 G$ F7 x5 ?! [ if (num-cars > count roads)- _! ~' A4 W- J v3 V0 e" j( v
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user-message (word "There are too many cars for the amount of "# M! P" U& X. y0 s6 n
"road. Either increase the amount of roads "
. Q; W& k# O W8 e! B "by increasing the GRID-SIZE-X or "/ x' M& A. r* b) {* p
"GRID-SIZE-Y sliders, or decrease the ". f3 m A$ e; v
"number of cars by lowering the NUMBER slider.\n"3 a8 g2 L: w# B' u( M
"The setup has stopped."); C( B- |7 \) @. x; x% k# a% u
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color) X; {- |7 P2 \, ]: G" {# I7 a, x
crt num-cars
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$ o2 G0 I. n3 }8 Y4 I1 ^ setup-cars% ]7 o d: v% I9 L8 V# C' T
set-car-color
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% G( }+ {' h r& Z; b: n/ u3 J: f ;; give the turtles an initial speed
/ \* r3 ]6 q/ Y* t7 s+ w3 E ask turtles [ set-car-speed ]' f2 u( r" }6 {. G
- q6 s8 T% [9 c5 f( c# i. [ reset-ticks
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;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
; r9 u& ^7 a: p6 s set phase 0
_; B3 ?9 W8 C6 v) f# \/ E set num-cars-stopped 0. C3 ]' g n1 i; p
set grid-x-inc world-width / grid-size-x
w2 r) B; b5 w; A+ H! ] set grid-y-inc world-height / grid-size-y7 f% d# w' |$ F m, g
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary1 ~0 L: r: F# S9 a% S/ \
set acceleration 0.099/ ?1 L0 F/ Q* |
end
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; W8 K5 M1 Y3 f$ V/ U8 D;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
) ~7 S3 I' S4 t6 @ W;; and initialize the traffic lights to one setting; C: p" ^) m7 Z# X7 J3 W
to setup-patches
( z: {2 L! o g2 R2 u9 M ;; initialize the patch-owned variables and color the patches to a base-color2 }/ \1 n& D2 F" Z: g
ask patches, A- Q. M& e$ q% W1 b: d8 j
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set intersection? false. A, W T* o7 t2 B! E
set auto? false
4 V) I Q: [ C% M& F5 H set green-light-up? true4 z' V5 D6 Y3 p/ W- W% |7 y
set my-row -1$ t1 z% |% Y# f
set my-column -11 G& Z$ P& X2 I1 `
set my-phase -14 A: n6 Q" U" q$ U/ |
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets4 c( s5 e4 h+ w: [$ {" d7 I
set roads patches with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 R4 f' b& u+ `* `) K9 u6 B9 ^
set intersections roads with
2 R% f5 p5 S! H7 B5 C& ] [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
$ u. T' e( ^1 J* s) i& c- q0 G (floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 z2 w5 l1 p% u
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ask roads [ set pcolor white ]" Z9 a9 V2 o7 @: }
setup-intersections# h2 t$ {1 P1 T0 p5 j; P! ]
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其中定义道路的句子,如下所示,是什么意思啊?
- S8 C5 B D2 c3 j* ~& o set roads patches with+ [- \5 O8 \% N+ l0 {: J: O+ `
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" N6 t5 B& Y3 G2 G B
(floor((pycor + max-pycor) mod grid-y-inc) = 0)], W& T+ b. ?7 m# B3 Z
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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