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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。/ V6 N- v6 O ?8 G1 N7 {9 Y
netlogo自带的social science--traffic grid这一例子当中,: w( C$ a$ G5 Z
globals. H( x9 A2 Y4 S& H
[
5 V- \3 P5 U$ @* e. I1 q5 g grid-x-inc ;; the amount of patches in between two roads in the x direction& f# B; F8 |2 @- J6 l0 ~
grid-y-inc ;; the amount of patches in between two roads in the y direction3 ^/ Y! [8 O* \* a0 C7 }$ [
acceleration ;; the constant that controls how much a car speeds up or slows down by if% o* K5 z6 n% }& X: d: G
;; it is to accelerate or decelerate
+ T9 e2 Q8 {2 m+ j phase ;; keeps track of the phase
8 t3 v, Q, W- j- S num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
/ J4 `4 @3 @# Y2 x X! `, D# [5 i current-light ;; the currently selected light" N! G2 g) Q4 D: o- e! x- R+ Z/ R1 A8 H
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;; patch agentsets* D& ? m* c8 O4 T1 Q1 e
intersections ;; agentset containing the patches that are intersections
/ h: Y/ j, B, e: I6 g roads ;; agentset containing the patches that are roads
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/ D2 N( e" m. i" O: t$ Z A u/ Fturtles-own, r% w: [" f' G
[
) U+ ]5 ^# A h. ]8 A* b speed ;; the speed of the turtle
" i" D! G, |* ~2 F& c up-car? ;; true if the turtle moves downwards and false if it moves to the right
B5 T- i* t4 d5 ] wait-time ;; the amount of time since the last time a turtle has moved
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patches-own* p0 o! U3 i7 D+ p' a# ]6 m- P% y
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intersection? ;; true if the patch is at the intersection of two roads
) A4 x( D: s4 m; O- r green-light-up? ;; true if the green light is above the intersection. otherwise, false.
* Z1 \5 G3 \+ ~6 y2 s! i" c2 ?+ M D% N ;; false for a non-intersection patches.
; [% T; l0 ]' b0 B1 b+ {0 p my-row ;; the row of the intersection counting from the upper left corner of the
* y- E( j' P9 E ;; world. -1 for non-intersection patches.
$ ^$ }7 ^- s0 k2 z5 ~& X& s my-column ;; the column of the intersection counting from the upper left corner of the
) ^ c% S- c! _' T ;; world. -1 for non-intersection patches.
( m0 k# i2 U% x# [2 {" }% u2 | my-phase ;; the phase for the intersection. -1 for non-intersection patches.
+ e$ e0 Q1 A( K# U1 g0 Z( i auto? ;; whether or not this intersection will switch automatically." A% ]% p# L% I* X5 v! D
;; false for non-intersection patches.
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* h' A( J a3 v7 h% g% {;;;;;;;;;;;;;;;;;;;;;;
1 ]( X4 G* G' v5 S. G7 ^8 u+ U, O! b$ L;; Setup Procedures ;;$ y; z. V$ D, z7 \/ k
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
4 ?/ e4 p& J6 e, P;; Create num-cars of turtles if there are enough road patches for one turtle to
- W1 |6 b( U8 n: D8 c/ k;; be created per road patch. Set up the plots./ `; N8 y8 n4 r0 c/ b5 X
to setup) G7 l, c) V/ t/ P/ \& \5 `
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
' ~* J+ z7 F, n4 I3 @( U setup-patches* g6 Z& ~. f8 j, L6 M' O! {- i
make-current one-of intersections- k; ]1 j. Z/ t
label-current6 x1 I+ e: {4 z6 | `! t9 N
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set-default-shape turtles "car"
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
# T, }5 [8 x9 {$ K% `; G" f* ~ "road. Either increase the amount of roads "
8 [- d. }" Y. L: y$ b* r1 R6 L$ L "by increasing the GRID-SIZE-X or "
7 C2 d: X/ l$ u& f( \' _ "GRID-SIZE-Y sliders, or decrease the "
4 e" a/ R( Y! A5 g! [/ I "number of cars by lowering the NUMBER slider.\n"
* p8 u) [+ K( c+ X7 F5 W6 W "The setup has stopped."), z. L, t0 N4 H) B7 \) O2 A
stop
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# w- e# W5 D/ ~4 j' J2 w ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
4 G( S" k4 g# ~5 Q' g crt num-cars
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setup-cars4 w. `, Y6 b; u% s
set-car-color2 A. U% _/ f3 s" \5 z- A3 {5 H3 G
record-data
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1 _% M. H) x2 N+ ]+ j3 p, m0 ? ;; give the turtles an initial speed
( Y3 r. n: x+ v" Z) A i4 M& d ask turtles [ set-car-speed ], _) H: C! f2 A O0 \2 w$ t q
2 j. D7 [' e0 b4 O reset-ticks$ p6 h F1 X+ G
end
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;; Initialize the global variables to appropriate values( c; t+ Z* [1 D G. ~ d0 N% F
to setup-globals" ]; \3 r9 y8 o% w' k& K
set current-light nobody ;; just for now, since there are no lights yet! U' X: K/ M( ?, V! V* D! L
set phase 0
) B% X: O" ?) v. s+ V ^5 P; m set num-cars-stopped 0# d' p9 h2 ]4 n( f E
set grid-x-inc world-width / grid-size-x- J* K( i- u7 P0 k( ?* y, n& I
set grid-y-inc world-height / grid-size-y& y6 e: p0 ~) o5 g+ S+ `
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary. Z* q5 S0 s2 X# V) a0 N- N. x
set acceleration 0.099) h8 C" @ e3 W0 @5 e: S
end* I- k0 {1 N% d- Q* r! ?4 {6 V: L3 q( ]
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,9 |) j% b+ @7 {, G' O5 ^
;; and initialize the traffic lights to one setting
( T% e9 r9 ?3 z+ i" w7 ]to setup-patches& G7 }9 ~# E' }7 `0 T& U `: Q
;; initialize the patch-owned variables and color the patches to a base-color% r5 L5 \- J, ]- `2 l. m5 ~0 x
ask patches. u* z5 |+ V% Y; ]1 y: g; n
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set intersection? false
0 r7 a; J& l( r! M2 C( f3 u6 ~ set auto? false( }3 n6 P! k7 A) I$ S/ `% {
set green-light-up? true4 r9 Y1 I* C' x$ c" a# n5 ]( Z, Y
set my-row -14 y: G) o' r- E& ^+ d: z! C
set my-column -1
( L/ |# r5 L7 k& c, k3 h$ t set my-phase -1- o0 _! W% H4 f( T8 G7 ]& a
set pcolor brown + 37 s- M. q: n P) Y2 I' Q3 \. B" T4 `
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4 p0 t' \9 S7 S ;; initialize the global variables that hold patch agentsets% ]1 q: s8 Z1 C
set roads patches with. L) _4 o, H" p! O8 `
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 O ]5 K& Y/ D: O. E( b4 I. f9 z5 ]
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 f# }$ T; P( }9 w: c
set intersections roads with+ J$ [3 P& h1 W. _# ~0 J |
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
4 W/ Z* O0 l, N |& W& { (floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 B( } f& ]7 T
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ask roads [ set pcolor white ]
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end
0 ~. o9 s5 m" O |0 z其中定义道路的句子,如下所示,是什么意思啊?3 Z+ D, i2 b1 r4 N
set roads patches with8 i8 v, j; w- d, U
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' h1 s# n& g9 g# Q8 V (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
+ ?) | c: C: N! l! F' A5 J- Y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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