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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。
* @& l( S6 k" u" Ynetlogo自带的social science--traffic grid这一例子当中,3 T0 k, @" T5 {- W1 L. D( F
globals7 v9 V" Z9 w5 i% X @
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grid-x-inc ;; the amount of patches in between two roads in the x direction! _1 x* ?. ~& O. q* ^/ }
grid-y-inc ;; the amount of patches in between two roads in the y direction' S. _$ q3 c. U# O
acceleration ;; the constant that controls how much a car speeds up or slows down by if
+ s- w% Q$ P" g E$ d ;; it is to accelerate or decelerate3 k6 U/ f. v* R& Z) E8 f0 x0 A5 _
phase ;; keeps track of the phase
5 I3 {! M$ ~; {/ J num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure) R+ k3 v' p- j; P+ p" R2 x
current-light ;; the currently selected light
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( Y7 S0 k4 f7 }3 R ;; patch agentsets
& N# i( Y7 ]8 a0 r. J7 q intersections ;; agentset containing the patches that are intersections
+ g2 U# o! w) K& E% k roads ;; agentset containing the patches that are roads
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) p* }. D1 [: B" _% y f, f# |5 H) bturtles-own( @6 O' B; n5 w3 l. `: Q
[
1 t& T9 C6 E+ l( X9 b1 F9 ^, F& h speed ;; the speed of the turtle# z1 O: a6 h% }5 y) b- Y1 ^
up-car? ;; true if the turtle moves downwards and false if it moves to the right, Z- @# `* h1 G( G9 \: {+ F
wait-time ;; the amount of time since the last time a turtle has moved. B# i9 ~: S2 y' C ]
]
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. S) e, I/ M+ [+ \+ G, Tpatches-own
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! Y; i- x2 ^* p/ J+ a; v( d intersection? ;; true if the patch is at the intersection of two roads+ y. k$ T! M$ j% z" o [0 W( r
green-light-up? ;; true if the green light is above the intersection. otherwise, false.$ H8 H1 j2 B, E
;; false for a non-intersection patches.
0 y& _% Y$ ^6 n my-row ;; the row of the intersection counting from the upper left corner of the% S8 Z5 S) D4 h, Y
;; world. -1 for non-intersection patches.
2 D5 x9 a* ` q7 \ my-column ;; the column of the intersection counting from the upper left corner of the
- R; o) `8 A" l6 O/ J9 C9 | ;; world. -1 for non-intersection patches.' _$ i" Z) y$ ~8 Z4 @* o5 @, c
my-phase ;; the phase for the intersection. -1 for non-intersection patches.8 V1 g( K& A, K6 g6 V) h2 _& C/ I
auto? ;; whether or not this intersection will switch automatically.8 O& K' I# ?9 h& m7 z
;; false for non-intersection patches.
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; Q* h: \- J5 E2 B/ E( h;;;;;;;;;;;;;;;;;;;;;;, i$ W5 E8 C2 d. N8 t! x
;; Setup Procedures ;;" r+ \( v" [- H& W6 d3 `' z3 v x2 _
;;;;;;;;;;;;;;;;;;;;;;9 \/ [2 A7 D& Q B
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;; Initialize the display by giving the global and patch variables initial values.- R) ] j, b, W8 Z7 Y6 K, p2 R
;; Create num-cars of turtles if there are enough road patches for one turtle to) q% j. P- w+ G- ^3 R4 K. ]8 `
;; be created per road patch. Set up the plots.$ \# P0 Q! v/ O b
to setup
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setup-globals+ o4 p5 {3 l4 C
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;; First we ask the patches to draw themselves and set up a few variables
: f* G2 E5 C5 Y9 Q' | setup-patches
s! \: v0 O6 l% O# L3 \ make-current one-of intersections
# i7 a* G+ a3 h, p1 w label-current$ v8 N6 D: o7 A* Z7 N
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set-default-shape turtles "car"$ B! [! X6 R8 E/ P/ ?! r
& e% K- p8 i) Z7 n8 W if (num-cars > count roads): o% h$ R' u" V& x$ V/ `
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user-message (word "There are too many cars for the amount of "/ ]/ a# v0 J& H
"road. Either increase the amount of roads "
# @& ~6 }" m8 x( O( F W: i "by increasing the GRID-SIZE-X or "
9 q, D9 ]8 F* T7 D "GRID-SIZE-Y sliders, or decrease the "& K3 C; s5 A/ z* a
"number of cars by lowering the NUMBER slider.\n") g) p3 H" K5 ]8 ~' p6 V
"The setup has stopped.")
" h/ u$ v/ ~0 w5 L% ^/ w* x stop
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) |) q! I, c2 W1 R; D5 q! O ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
9 d9 K* @' |0 X, @9 I) }4 U3 u crt num-cars
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4 g+ J! a- G& j: M9 U+ I setup-cars2 T: B2 J4 b" M) W2 P/ V
set-car-color
2 z9 J5 e5 A$ y& |$ D' T( E record-data
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. V g9 x8 b% X, f( ]& q! q ;; give the turtles an initial speed+ q+ \ ^/ S" q
ask turtles [ set-car-speed ]
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0 l4 J$ |, E) P, ^ reset-ticks& _2 C( e! g. O5 E
end0 Z6 G7 y \6 {
3 ]3 n6 J6 j, l/ @5 ?. T;; Initialize the global variables to appropriate values' h7 ?. |7 k" Q2 S) B0 G
to setup-globals) b2 U7 X, J6 z2 s& A. }( U+ p7 r
set current-light nobody ;; just for now, since there are no lights yet
Z5 ?2 H4 ?( H; F; t set phase 0
3 t5 v3 l8 i1 d9 q; m* ` set num-cars-stopped 0' I& r' a9 A. j- D
set grid-x-inc world-width / grid-size-x
6 X' E, C- K2 M: I& b set grid-y-inc world-height / grid-size-y: |2 d. m7 Z. _. R% B4 v& k ~# P
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary, \- r2 f3 M w5 ~1 _; d) z1 L
set acceleration 0.099# ?3 M6 x! Q& e2 l: X
end3 @2 ?( O$ X+ ]9 i. ` E! Q
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,% E, ]1 M! M, {: D8 B' o! j
;; and initialize the traffic lights to one setting( p% g1 A- ]( n: W+ R5 c
to setup-patches* N( w/ C. |& o3 Q- C! `- _& S) D
;; initialize the patch-owned variables and color the patches to a base-color) W+ M5 p4 V2 J7 Z5 y% h# z
ask patches
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, w- K4 I2 \! d$ o8 ^9 Q m set intersection? false
3 m6 |9 ?8 }5 O7 E4 z/ q set auto? false
& l+ f. d3 U( P set green-light-up? true& Z3 m% L6 m+ t
set my-row -1& V) {. k Z2 |% Y) F3 f
set my-column -1
: J" m5 f7 R( j6 s6 z% _! ~ set my-phase -1
7 \7 D, E3 `: I/ n1 i" | set pcolor brown + 3( Y! A# Q, @' a$ u4 J
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7 O' N. } H0 V2 U2 }& k ;; initialize the global variables that hold patch agentsets) O( p# Y3 F; |4 a+ m
set roads patches with
& f+ I: N$ Z) x+ X! X: z! x- `. z [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
, u! N4 o2 S9 B" L (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ t9 D/ y( Z5 I$ ~* G2 U3 U set intersections roads with
. z A5 O5 a) s" ^1 P) A: d [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
& F9 D: y5 m: e# |3 { (floor((pycor + max-pycor) mod grid-y-inc) = 0)] ?6 p/ Z: e; V5 N5 _0 @! L
2 N; e6 t+ n5 W) A. s3 [+ D4 y ask roads [ set pcolor white ]; o0 f4 X4 ]' J* Q5 y- x
setup-intersections
$ z* x" `6 j3 U% @* s9 Rend
4 N* Y9 g+ E/ X/ `' N' \其中定义道路的句子,如下所示,是什么意思啊?
6 L4 x, h; S0 W# e set roads patches with
' Q1 v0 I/ a, t, j [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
) } @" ]( F2 c: ?$ J (floor((pycor + max-pycor) mod grid-y-inc) = 0)]) N$ C4 N; X/ F7 O* R s+ S" O( J, b1 Y j2 x
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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