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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。
; R) s0 p2 d- hnetlogo自带的social science--traffic grid这一例子当中,
5 y8 j L$ d; H w3 C3 |" vglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction& j6 s8 e# K$ a) O" G0 q
grid-y-inc ;; the amount of patches in between two roads in the y direction
& ^% {/ h& L; x acceleration ;; the constant that controls how much a car speeds up or slows down by if+ @4 ^2 c$ f. N4 _: z
;; it is to accelerate or decelerate/ N9 v+ k P' M: Q; ~! b7 m( u. f# n
phase ;; keeps track of the phase
4 S9 @6 ]5 _* K. o7 I- [' j; E! u num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
, {& W' A7 v: I! k$ F current-light ;; the currently selected light: x! o: r* F+ p7 Z. z4 l& i# g
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;; patch agentsets
( ]$ B) g$ e7 T8 B, @ _ intersections ;; agentset containing the patches that are intersections
! g# [% z: t9 s roads ;; agentset containing the patches that are roads
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7 ~/ n% j0 J3 Dturtles-own
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) y' c$ m; g) Q* @7 i9 ^+ ` speed ;; the speed of the turtle
9 ]& S: R9 k7 l3 L up-car? ;; true if the turtle moves downwards and false if it moves to the right6 w3 G! l+ G& p( ~; _ n
wait-time ;; the amount of time since the last time a turtle has moved
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) r9 U) k, [0 q* H9 c1 Apatches-own
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intersection? ;; true if the patch is at the intersection of two roads
4 X# b/ |. }, m2 O9 W: n green-light-up? ;; true if the green light is above the intersection. otherwise, false.1 z) i& |6 s @# R" R- M/ k
;; false for a non-intersection patches.
) o$ z @; n" |5 P. b my-row ;; the row of the intersection counting from the upper left corner of the
" ?. @; U; O3 I ;; world. -1 for non-intersection patches.
( `& B3 Y- V. H3 A my-column ;; the column of the intersection counting from the upper left corner of the
`, b% V, K- A* ^/ q' D. b ;; world. -1 for non-intersection patches.
, x! _( y% R8 z; G' |+ m my-phase ;; the phase for the intersection. -1 for non-intersection patches.9 C/ o6 o; s+ H6 y. c8 n# j
auto? ;; whether or not this intersection will switch automatically.
: k0 D# m# F- Q ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;5 Q+ e, K( x! t$ v x
;; Setup Procedures ;;7 I, R0 N/ |' O# e5 T* z4 e
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
; \. _$ _" w9 q* W2 S' b$ q" |- X;; Create num-cars of turtles if there are enough road patches for one turtle to, s* b/ r m9 ?
;; be created per road patch. Set up the plots.
! a! f4 W0 Q3 vto setup
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
+ y: ~# x) t. c( s* m% u+ y setup-patches
$ ]' k; {+ ?% F I9 p( a make-current one-of intersections4 \; y) G% N ]: q
label-current
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$ ^& E8 k: A, _! d set-default-shape turtles "car"
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if (num-cars > count roads)# a, L: K5 L8 P" d/ J
[
5 v# z7 D/ M4 ^ user-message (word "There are too many cars for the amount of "
. L d+ w, q. j Z M D "road. Either increase the amount of roads "4 q: @+ o. k4 h+ m8 P
"by increasing the GRID-SIZE-X or "2 e2 |: z2 ]3 ?5 u, `9 u" |
"GRID-SIZE-Y sliders, or decrease the "9 B2 Y# f$ @0 L7 O
"number of cars by lowering the NUMBER slider.\n"
/ J+ N! r0 P0 A! ] "The setup has stopped.")
4 n4 m/ k/ j" P; h# g: P stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color' F; N. W7 |( n& E: M: y
crt num-cars+ q2 [% W2 t% I! p. u' ~
[
3 K) D2 ]/ T D setup-cars" Z! P! N/ K5 M5 [" B2 [
set-car-color
( m5 V) q2 K. P* o) U6 M, _9 h9 T record-data
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;; give the turtles an initial speed
( F& M( j+ \0 S9 e5 ?) j ask turtles [ set-car-speed ]
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/ z" N' {! k) t" T* X% I reset-ticks. r* m; @- j2 L6 z% ~$ y- m$ i/ A
end' P2 N* Z2 n: Y0 Y
2 [1 i6 @- q5 z3 a; R;; Initialize the global variables to appropriate values# N5 Y, `+ j1 }. I
to setup-globals
* w. Q' A% K6 g2 _ set current-light nobody ;; just for now, since there are no lights yet
1 ]+ Z" u4 t J1 T. J3 I7 r set phase 0- w# q! L/ R( b# \8 Y
set num-cars-stopped 0- ~' S. ^% k- C& P( A4 Q0 T
set grid-x-inc world-width / grid-size-x3 b c+ j. F- k8 ?+ d
set grid-y-inc world-height / grid-size-y
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( i( U3 I! k; ]7 P4 Q" G6 y ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
" G3 N' x. ~& q7 z( ?; x: G# m set acceleration 0.0994 O' @) U/ Y2 j! j8 j, W* `) l( B7 J
end( m% E! b4 R1 j! v/ `
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,+ r# }' g- {; c" o6 ]6 n* Z
;; and initialize the traffic lights to one setting
) ]5 R1 ]4 j3 Q; kto setup-patches
" f% v7 h% Y* `4 x6 U- d! g ;; initialize the patch-owned variables and color the patches to a base-color
. y+ Z0 _$ ?: X( y* U) ] ask patches* ^! p I8 _* y3 I! w
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set intersection? false( u& b3 M: Y9 Y
set auto? false
* X0 O6 M2 q- H$ M( \ set green-light-up? true6 c: d, r! c$ N3 ?
set my-row -1: C8 [+ L2 T" `/ w. f# X+ {* L5 r
set my-column -1
8 e) f1 L- j6 t* V: x) j set my-phase -1% p1 x# E: p$ a: S) G- w
set pcolor brown + 3- {1 L8 X0 N. I( Z7 D6 i! y
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5 n' y3 P, N' }% D* d ;; initialize the global variables that hold patch agentsets% `) d' j2 J7 ~2 T2 U0 h
set roads patches with
0 u" V- Q9 b$ Z [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 c/ g% o6 {- O O- @1 o (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. h% z7 N" d f8 C) M6 z set intersections roads with
5 G! g4 K# a3 R, G* G [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and, ?$ i$ G. s# A$ I: z U
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 g( W& R! c6 P, r% j* Z* x
) S3 Q+ [. @! S+ w G' F, [ ask roads [ set pcolor white ]2 I' u) S/ \# W, i: G. e0 y. g
setup-intersections. n1 z' J4 A9 M! G+ V
end3 M, w0 j) }) R1 V. J# @
其中定义道路的句子,如下所示,是什么意思啊?& A/ h1 I+ x: Y" E4 p/ h
set roads patches with- {/ C. w3 `" U2 C1 s) U- W
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" I/ I- q: x, |8 N7 D( C9 ^ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]; B7 q6 u7 j1 ~( q* k1 V
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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