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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。, `* C9 Q0 s* F7 _# l
netlogo自带的social science--traffic grid这一例子当中, @1 g3 D9 f) X
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" L M8 \3 F2 c* { grid-x-inc ;; the amount of patches in between two roads in the x direction
; l8 L) C4 P9 h$ M( b grid-y-inc ;; the amount of patches in between two roads in the y direction
. u5 y- [, [0 l. R) j; d* ? acceleration ;; the constant that controls how much a car speeds up or slows down by if. ~4 j1 c( `7 Z3 S y
;; it is to accelerate or decelerate
) H% a* g' C6 i. c3 t phase ;; keeps track of the phase
- y2 `, H; F/ L num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
/ h& U+ i2 _9 M! ^* l7 r current-light ;; the currently selected light. P- a6 ~& [# p3 V( U. P
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;; patch agentsets( S5 N6 Q* G' F# R/ }
intersections ;; agentset containing the patches that are intersections
T! m& H6 H. v4 l! J roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle
* }( Z+ J0 d7 |3 \2 R up-car? ;; true if the turtle moves downwards and false if it moves to the right
% [( A( G) @ M. }$ P! \ wait-time ;; the amount of time since the last time a turtle has moved1 I- q$ x- D4 a
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patches-own
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3 r6 P. l- b- X+ C intersection? ;; true if the patch is at the intersection of two roads& s, k( P5 Z7 Y
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
- O% s% A. h! [8 q ;; false for a non-intersection patches.8 X9 b8 e* {5 n$ V: M! [( V
my-row ;; the row of the intersection counting from the upper left corner of the
. k! V' l# C- W- f ;; world. -1 for non-intersection patches.
% z/ }( m0 L2 _7 j |( R my-column ;; the column of the intersection counting from the upper left corner of the5 {6 p5 {4 ^- ?- h$ s" Z$ w
;; world. -1 for non-intersection patches.+ X+ x5 ]# q8 g; M! |% I
my-phase ;; the phase for the intersection. -1 for non-intersection patches.- I' m1 o. y& K0 q u
auto? ;; whether or not this intersection will switch automatically. \% v6 l# {+ ?$ U" l8 o$ _
;; false for non-intersection patches.- b i1 e! p$ \% k' N& z" g
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;;;;;;;;;;;;;;;;;;;;;;: B6 F3 l+ R& x1 {9 Y6 a2 b
;; Setup Procedures ;;
1 t+ H" S( o; f% R;;;;;;;;;;;;;;;;;;;;;;" \3 @ b. O. ^
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;; Initialize the display by giving the global and patch variables initial values.
7 b9 Y3 e) f N) `, H. g; d$ @* I;; Create num-cars of turtles if there are enough road patches for one turtle to
; ^% T( I7 V7 s) p;; be created per road patch. Set up the plots.
/ C8 N3 ?9 S0 y" j8 fto setup
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: h& x3 k) j W, Y) @3 F1 _4 X setup-globals+ X" ~1 E$ f& B3 N% r
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;; First we ask the patches to draw themselves and set up a few variables# S V S0 f2 E L, Y' D% g# ^
setup-patches
# Y2 I, s$ Q) P make-current one-of intersections
3 B* k' E+ [/ n/ e5 w: o5 M* j label-current* _8 f* {9 d# x
- t: }7 D- I) M, L3 R# o set-default-shape turtles "car"
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/ w2 j6 Y& T9 o$ i0 l- v/ {! a if (num-cars > count roads)
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) _6 S% }$ p' X user-message (word "There are too many cars for the amount of "
( {* g r9 p$ _ "road. Either increase the amount of roads "6 e$ I) P, s6 N# S$ x. E, k
"by increasing the GRID-SIZE-X or "
1 U$ Q. W+ H- A) i "GRID-SIZE-Y sliders, or decrease the "
8 v; B1 [! G2 h0 K "number of cars by lowering the NUMBER slider.\n"
; K% G7 a9 c# o6 T0 ]& S "The setup has stopped.")5 i. ~8 c# p! I4 L
stop2 c e* B6 i- ~5 x0 [8 D C# D
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6 T ]2 p" N, o( b ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
% \6 W! F }6 S1 O' O crt num-cars
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setup-cars9 y* f, j% E9 X; M- L& I/ y
set-car-color9 B% i; G% c9 y1 H/ @, }
record-data" d& |7 `' u: W4 q/ E
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;; give the turtles an initial speed
; J; a* c3 K `* n9 Q( X. B ask turtles [ set-car-speed ]
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$ \! q2 o# ?7 _, d4 A2 s* p5 Q reset-ticks
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( E. O1 o/ d, U' M) R1 j;; Initialize the global variables to appropriate values
" o, f* g |' }to setup-globals
/ v; i3 F' M% ?! Q1 [- r9 i set current-light nobody ;; just for now, since there are no lights yet
/ Z2 v& o$ F1 L+ Y4 u, E9 m: L" ~ set phase 0
2 M+ E3 e4 h. }* V: e set num-cars-stopped 00 X6 u( M! T8 {+ N, r' G I6 G
set grid-x-inc world-width / grid-size-x
& q* K% D! X5 W3 \2 N set grid-y-inc world-height / grid-size-y+ _$ b( d9 j* U; ^1 F
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary$ k$ p! x& c0 n2 t; U
set acceleration 0.099* v# K8 Y7 C: M% C) G
end$ K! v9 I( I0 C t/ c
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,- ~4 x; M6 S" n7 K* I4 I
;; and initialize the traffic lights to one setting
5 I/ \4 p( C+ ~to setup-patches
' m8 k6 d6 K' g" r% t9 } ` ;; initialize the patch-owned variables and color the patches to a base-color* u! L! X& _$ f$ q6 ~
ask patches
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set intersection? false
* ]6 V: B! N% o! ] set auto? false
* N2 e7 b9 s# I6 v5 R set green-light-up? true1 z9 r8 g0 O+ B4 D
set my-row -1
/ ]2 V# w' x+ N5 W set my-column -1
% k4 X- V' U& |5 |0 v set my-phase -1' q) u" p; o; s. _, B6 h% |% J; e
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
9 T. _3 g0 R( j# j; i set roads patches with
$ Q. k. }9 x! M8 | o [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or! x# L* n' E! S
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 l1 T q( e. u, ]
set intersections roads with2 a$ {+ ^6 s0 w: h! \
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and/ d! x: t% P$ R" `* e
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]: H5 S9 c6 [* X' }. R7 p$ s
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?5 ]( `: i$ V- {' Q4 G, a
set roads patches with
% a/ u" T+ S6 k. \$ L [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
& c w/ n- F9 M7 n2 m! B (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
! p$ ]8 b& K9 m0 ^4 x/ t8 Q4 ?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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