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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。
: c( s6 x0 e: z: }netlogo自带的social science--traffic grid这一例子当中,
, Q+ V, O$ d4 h0 T( m) gglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
: Z# C9 r( @6 y! f" }; v grid-y-inc ;; the amount of patches in between two roads in the y direction
( [0 |0 F& R: U acceleration ;; the constant that controls how much a car speeds up or slows down by if) X r3 w2 p" E9 S0 q3 f' P
;; it is to accelerate or decelerate
9 {. Z. X- P: h2 i8 ~! f5 U phase ;; keeps track of the phase
, w: E; N* e( \, e num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure: |' [' F. r* W1 h7 ?
current-light ;; the currently selected light" G2 d2 n; f) G
6 q. y2 T+ Z+ l" z9 | ;; patch agentsets+ E: Q, a C* h7 J% d- N5 I
intersections ;; agentset containing the patches that are intersections
T# e6 z( s. l) D& L roads ;; agentset containing the patches that are roads
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turtles-own$ U% |7 l) q3 U9 o1 w" }9 K- W
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speed ;; the speed of the turtle
2 f& j7 m$ D; m# P# A$ a up-car? ;; true if the turtle moves downwards and false if it moves to the right0 d) w; L( t2 g" f0 J
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
. @# C a( y) ~: [7 K$ Y; y green-light-up? ;; true if the green light is above the intersection. otherwise, false.
" J" w* N" H; v! K/ Q ;; false for a non-intersection patches." U0 ~# A, W- b h
my-row ;; the row of the intersection counting from the upper left corner of the
0 Z+ H1 m/ Q0 ]* ]( ^/ o6 c ;; world. -1 for non-intersection patches.8 ]+ }) t" A+ J4 E O
my-column ;; the column of the intersection counting from the upper left corner of the
' U" g$ E% E# t" g3 K ;; world. -1 for non-intersection patches.' p0 X9 C* U& z# B8 v
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
- n9 ~3 A8 \2 } auto? ;; whether or not this intersection will switch automatically.* z2 ?* U& m! r6 y- C4 J
;; false for non-intersection patches.
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; K! ^- C( y" T/ k8 F;;;;;;;;;;;;;;;;;;;;;;; ]" Z, }7 l$ L: i0 P% x( U
;; Setup Procedures ;;
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1 z$ F. A2 m3 R* E. Z# H. N; h;; Initialize the display by giving the global and patch variables initial values.
" x6 q: F |4 M/ R! \;; Create num-cars of turtles if there are enough road patches for one turtle to
9 B$ t$ P! O e/ \0 P( E1 G! J;; be created per road patch. Set up the plots.
! {% r7 z$ O. { W8 Rto setup
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setup-globals
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# d, M' I9 y0 K; x0 z& ] ;; First we ask the patches to draw themselves and set up a few variables5 @7 V' O# b( M( n/ C
setup-patches
- q4 g* R, {6 G% A make-current one-of intersections
* A4 ?# ` N8 h) t label-current
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/ h- M# r @0 | set-default-shape turtles "car"& v( O' N1 e$ w! A7 b2 h
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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 "
9 O( T5 }# [" X: k$ s6 U "road. Either increase the amount of roads "
! M+ T- j9 h/ A: t$ R) ?( q "by increasing the GRID-SIZE-X or "0 n9 A/ n7 g. V! f, h7 F
"GRID-SIZE-Y sliders, or decrease the "6 \6 T; e3 D8 _# `, \1 c
"number of cars by lowering the NUMBER slider.\n"
1 y3 u3 W0 t* y0 v "The setup has stopped.")6 a# O8 L& v% u
stop5 C: d8 G9 ^- ?0 T& G
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. Q+ N: W3 c6 x/ e ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
# D9 s" m9 W% h: ?% M. J: f, n crt num-cars
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, b* O! e$ r" D8 ^ setup-cars
, [- I4 X3 q( c# [ set-car-color _) q& z3 @) d6 u6 ?
record-data
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;; give the turtles an initial speed
& m9 M. W( d" n" Z* e ask turtles [ set-car-speed ]* A! ?1 o3 Y) w/ E5 w: T2 R; N
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reset-ticks3 v$ ]2 A b* r& h5 Y/ ?
end2 E: x, i2 d0 V# x8 r) G
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;; Initialize the global variables to appropriate values% S8 ?5 }1 M9 P% e! H" B$ X/ T
to setup-globals
' G; K9 ^+ t( ?2 g, Y; b8 P0 i set current-light nobody ;; just for now, since there are no lights yet+ M4 U$ v/ ~+ {) K+ V: e3 e
set phase 0( i& R/ s* X- _: Z# ^8 k
set num-cars-stopped 0# A+ f* M/ J# S( k; {2 n, V
set grid-x-inc world-width / grid-size-x- @. w; A/ `8 a: s( f+ l7 o) U9 o( g. `
set grid-y-inc world-height / grid-size-y8 V# l# P! o3 b# y) O# ~9 _; g
6 N7 g- F5 S1 S5 K5 S ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary! [1 J6 f% ~; j) q. Q
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets, E) t: f/ ]* ^ o
;; and initialize the traffic lights to one setting
6 U) Q8 S* _$ o$ Z6 F% \7 B/ `to setup-patches4 a8 v9 x1 b# A' L, P' n* [3 A
;; initialize the patch-owned variables and color the patches to a base-color
E. j8 ]6 x# _: h. |" U( ` ask patches% P7 {/ P9 F8 [
[
' \- P+ o6 S; L. V! X set intersection? false0 W1 f; M" N4 O/ R
set auto? false
' j8 F+ X$ P7 v. ` u0 l3 a; \& ^! w set green-light-up? true
8 d( E8 ~) h1 ?& o" D set my-row -1- X( Y& o" z5 O+ {: t
set my-column -10 `5 U. s; m' S6 i/ x! c$ o
set my-phase -1
& {- c; t5 P$ F Q! g6 v set pcolor brown + 3: A( m0 @- ?9 v
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4 c, F1 `2 H* S |3 n ;; initialize the global variables that hold patch agentsets
# h" W! Y9 ?' C4 G; l set roads patches with
: a. z7 C! G+ z( s6 B7 q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or9 y( o! X, c+ t6 c
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]* K3 ^+ V# z0 g; J
set intersections roads with% l+ I. _8 R' R3 Y& W
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and( o. K9 I! ^; |& n
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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1 X ^, m0 E% ~8 \, i ask roads [ set pcolor white ]
/ r" i! ~0 `7 j; H0 l7 x setup-intersections/ i" X, u- P1 ^5 E' C* _
end9 K* o" M9 w0 I' N. v2 ]
其中定义道路的句子,如下所示,是什么意思啊?
; X3 j6 G$ M Z: e% _; ~ M set roads patches with
- F, z% [! |5 z3 B9 \4 q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or W. ^) M. F3 F* E" `& N
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]& ]( ]# T6 a9 E5 j
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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