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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。0 w% ?! w8 U s9 K$ \
netlogo自带的social science--traffic grid这一例子当中,% r9 K O$ A) M5 `1 b, N( t
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
/ b/ C* r: Z( N, L& Y- ] grid-y-inc ;; the amount of patches in between two roads in the y direction
4 t1 w& v9 x$ v0 a' v* f9 [ acceleration ;; the constant that controls how much a car speeds up or slows down by if
1 W$ T% u* Y1 p, I ;; it is to accelerate or decelerate
' b: m: }# p2 s phase ;; keeps track of the phase @, G8 \! I- p2 `9 ]: y
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure% r+ U# i- c' j+ s4 |: o
current-light ;; the currently selected light+ i3 H% w( x% F/ S. S7 J, D2 z5 S# u
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;; patch agentsets
( h4 F a: D6 A" d0 I( H intersections ;; agentset containing the patches that are intersections
( _$ q/ d' R0 V k% A- a4 N roads ;; agentset containing the patches that are roads' Q9 d [! F3 A9 d& y* u
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6 x# ]% T& g8 [9 T6 [turtles-own
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7 ]$ P9 o' }6 ]6 o9 [; @* W speed ;; the speed of the turtle
+ l1 K3 T, Y6 c up-car? ;; true if the turtle moves downwards and false if it moves to the right
# w: H! I' @+ r5 q: Y wait-time ;; the amount of time since the last time a turtle has moved
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) Y1 k( n" I7 m+ O7 O/ d6 Qpatches-own' q7 t* b" k2 |
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6 o( W5 E% x* T1 W1 D intersection? ;; true if the patch is at the intersection of two roads
1 D# \1 X# B# c* k5 w green-light-up? ;; true if the green light is above the intersection. otherwise, false.
: @* ~" h# k6 } ;; false for a non-intersection patches.% O" M W- u1 Z
my-row ;; the row of the intersection counting from the upper left corner of the% ]+ Z3 r* u7 y: C% M
;; world. -1 for non-intersection patches.% r p4 ~! K$ ~- E
my-column ;; the column of the intersection counting from the upper left corner of the$ H' {. C: v! a7 G& i
;; world. -1 for non-intersection patches.
. \8 s. W3 H5 M2 f5 @ my-phase ;; the phase for the intersection. -1 for non-intersection patches.
$ F" p: m( F3 v+ c. _$ }. c auto? ;; whether or not this intersection will switch automatically.
+ r& A( _% b. J/ X ;; false for non-intersection patches.& f" w4 @5 s' |5 c
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; }+ k$ Y3 _% g;;;;;;;;;;;;;;;;;;;;;;& |" q8 p2 F& P9 W) H! l
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
2 O# H0 X/ T& H" l$ | C( P+ N;; Create num-cars of turtles if there are enough road patches for one turtle to) ^( L! m$ H7 _! f3 ~
;; be created per road patch. Set up the plots.
7 P7 D- Q/ _0 `0 }( i, H3 o! Hto setup. ~. K1 @/ ]4 \/ T+ S/ H/ p$ U
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setup-globals8 V, ?: H) \% ~/ z
4 F( a( v# h; ^7 a. A0 R' d# v; U; o1 ~ ;; First we ask the patches to draw themselves and set up a few variables
& w. g9 W6 w* A7 d9 K N setup-patches
6 f: F& z) C; Z make-current one-of intersections* `: h1 g& h x: ?- P9 E
label-current' D& s8 ~# F8 U4 b% {2 Z' c/ T) b
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set-default-shape turtles "car"
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7 M+ N/ S5 _% r8 c0 ] if (num-cars > count roads)
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! [! E8 H" \9 ]$ @- L. O1 J user-message (word "There are too many cars for the amount of "6 U, D# M% u9 @, B; _
"road. Either increase the amount of roads "$ p+ r2 c5 ?# j
"by increasing the GRID-SIZE-X or "
* Z' [; r' ~8 V% k! y- P0 B "GRID-SIZE-Y sliders, or decrease the "
) X+ A; A9 P& ^% n4 w "number of cars by lowering the NUMBER slider.\n"; A) V Q3 H" \# U0 h* a
"The setup has stopped.")
d& _6 U2 f$ q: e; z) I' T stop4 V, { G- W2 R
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* Y9 l6 P" |, l. V5 T/ `2 T- Z2 | ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
9 _7 B; |% \/ U# c( I crt num-cars
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0 \/ ]. O$ c* t: q3 r$ N# |0 L8 U setup-cars
3 S; w* H/ J) V2 v+ \1 u0 M: P set-car-color. T( b3 _8 Y4 B4 B. a1 Y" u' h
record-data1 W+ d; S% w1 o5 N8 {& c
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% Q" e- ^: S2 U ;; give the turtles an initial speed# o2 t) Y# c$ ?3 b6 W& D! M8 M) n
ask turtles [ set-car-speed ]8 C: f7 W9 T2 U6 } h1 ^
9 j$ [4 P% `! Q$ q# f' ~: } reset-ticks5 e w1 p) s9 X" t s U3 J
end2 ^( c) E9 A1 |' ?) ?
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;; Initialize the global variables to appropriate values$ Q* @2 w5 x. L L s9 m9 O
to setup-globals
3 P$ S5 T2 h+ p set current-light nobody ;; just for now, since there are no lights yet) t0 O- ]. ?2 {$ X$ C
set phase 0
3 }- a* l+ D6 h/ g set num-cars-stopped 0
) _9 W9 N* t4 s; Q2 b6 o set grid-x-inc world-width / grid-size-x( R; a6 h) U/ N$ b9 q; h
set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary( R! C4 [% [0 v; O, m0 I/ \
set acceleration 0.0992 n+ V" ]$ r f& b6 l' {! L6 {! \3 t+ [
end
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) a4 z7 V# X$ Z7 {- }! |;; Make the patches have appropriate colors, set up the roads and intersections agentsets,$ z( D! Q; @* j8 X& I
;; and initialize the traffic lights to one setting) k- {# T, F% T1 f9 g
to setup-patches
, G3 { c+ A. Q3 N K. p& A# _ ;; initialize the patch-owned variables and color the patches to a base-color$ M) n# X* o# n7 g, P4 `! w" ?
ask patches) l: a" h- ^3 i8 U' Q N
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0 o; q# F3 j2 c6 C$ r. u! [4 N! f set intersection? false0 \! G2 R" b3 S0 g: J# p7 l4 t/ O, S
set auto? false
! ^9 U- c |8 E% H set green-light-up? true
- w5 Z7 K5 |% Q6 m6 B$ h set my-row -1
4 i* h/ S6 ]5 H7 } set my-column -1
" A- o1 ~* A4 ?& O set my-phase -1
( X4 T7 |# o. B/ N* B; x set pcolor brown + 3& Z4 z" V! T! o' ^% Q+ z2 c( d
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;; initialize the global variables that hold patch agentsets. v: e" K$ V) a
set roads patches with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ ]6 W/ s" q4 }* X6 E set intersections roads with
9 K1 c+ w _* l+ f* m [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
K! u. D$ R) q3 \# s& J (floor((pycor + max-pycor) mod grid-y-inc) = 0)]% T6 K0 W) C9 L2 O _. ? ?% c
4 `& H( @+ k& o p ask roads [ set pcolor white ]3 b1 U* @1 j5 n+ {6 K
setup-intersections' h) `& P, n5 y; v2 L% W
end) s4 \& }% m- g( V% ~! Z
其中定义道路的句子,如下所示,是什么意思啊?3 Z9 a4 c! C2 S
set roads patches with
% l7 x2 t. V6 {; x) Q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
$ F& H# @+ _# J7 j. Y2 g% I (floor((pycor + max-pycor) mod grid-y-inc) = 0)]& p h- O- K, u A- q
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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