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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。
/ N G P; T2 T* k. fnetlogo自带的social science--traffic grid这一例子当中,
9 g O) `7 g$ r$ xglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction7 }" |/ H8 j# g
grid-y-inc ;; the amount of patches in between two roads in the y direction- _7 z0 c' M- N5 K5 b" e
acceleration ;; the constant that controls how much a car speeds up or slows down by if" X+ l3 Y% g& x" @: r. I* G
;; it is to accelerate or decelerate
+ q" o4 j0 J; P; `! V( ~ phase ;; keeps track of the phase
. X) v* w# Q( k6 C$ }0 M num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure9 o- S4 B5 s+ R: c# R7 M: ?
current-light ;; the currently selected light
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;; patch agentsets" x1 K+ J9 u9 N; z
intersections ;; agentset containing the patches that are intersections4 {- A5 s3 e& p- ^5 x
roads ;; agentset containing the patches that are roads: S$ s/ w0 ?; I+ x
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' ?; A8 Z8 Z, L) k Uturtles-own1 C/ @& }# W2 {* y5 f( d
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speed ;; the speed of the turtle
/ y! }( g2 {. q8 U, V9 E- h8 D up-car? ;; true if the turtle moves downwards and false if it moves to the right0 T+ A7 @5 v6 U' C8 Y. C/ q3 P4 g. s
wait-time ;; the amount of time since the last time a turtle has moved
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4 y" c" _1 N Z$ H' }9 epatches-own4 c/ r7 r7 L& ~, e
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intersection? ;; true if the patch is at the intersection of two roads
& Z5 f9 _# S2 [9 Y green-light-up? ;; true if the green light is above the intersection. otherwise, false.; x0 F- ?5 m) E
;; false for a non-intersection patches.
, x3 l1 K" P- I& V( |4 J my-row ;; the row of the intersection counting from the upper left corner of the- i( v; S' u8 l, }4 x& J/ m
;; world. -1 for non-intersection patches., ^6 A/ q& [3 i( t
my-column ;; the column of the intersection counting from the upper left corner of the
) q0 R6 i$ g: c7 G ;; world. -1 for non-intersection patches.0 H: y- R$ G) I! k% v
my-phase ;; the phase for the intersection. -1 for non-intersection patches.& x* ?' [* k' G3 G
auto? ;; whether or not this intersection will switch automatically.; }/ V$ Y$ A. M9 u. @! s% [
;; false for non-intersection patches.5 `( H' n3 @" x6 U& `# [$ G0 a
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;;;;;;;;;;;;;;;;;;;;;;; E5 l- r6 F: e, A1 e
;; Setup Procedures ;;
5 F4 R$ ^; h8 H- `( m9 D6 U;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
8 h4 f0 ?/ [. u9 K% L! a;; Create num-cars of turtles if there are enough road patches for one turtle to1 n* I2 ]0 M0 S
;; be created per road patch. Set up the plots.- C% C) ?8 z2 f- `
to setup" X% R: _4 ^! S2 J% U+ M
ca
/ a0 i& u/ e: ^* h" y+ \ setup-globals' L* F5 V9 c& U' E
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;; First we ask the patches to draw themselves and set up a few variables
9 [, @. C7 H, y* `% p: h setup-patches! r* N' I! k& v3 r$ ~9 w/ D
make-current one-of intersections
: Y5 s9 b. j/ N9 ?4 e label-current
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( o! ]& Z3 l: s. N( I3 ~- I set-default-shape turtles "car"
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if (num-cars > count roads)4 b2 e; X$ K x) x' z( i: u( H. L3 X, v
[
: N) I3 I' l3 H: H0 z p user-message (word "There are too many cars for the amount of "
1 q1 p4 u' }5 I+ e" c* G "road. Either increase the amount of roads "$ `% `/ X/ ] s5 |% z1 R
"by increasing the GRID-SIZE-X or ". h, \, A7 u- h" w
"GRID-SIZE-Y sliders, or decrease the "* E6 j5 k, m9 q2 N
"number of cars by lowering the NUMBER slider.\n"
' b8 W" u/ O7 h m: [ "The setup has stopped.")* W5 |! v4 Z% s0 E6 D# y z9 D
stop$ S' g N Q0 p. u& f
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
! s* e9 i# T+ L. d- i6 ]9 u crt num-cars
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; t8 ~+ O, X4 `2 p& ]" e setup-cars7 w, P5 U X: A- H6 R e; L
set-car-color- X6 i3 G) ?1 s; a# ~' x! M
record-data& T( J8 e; y' Y# e% J. a$ q+ ]$ x- p
]
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;; give the turtles an initial speed
2 d) @5 H& E) K: O- Z7 m. \7 z% N ~8 j ask turtles [ set-car-speed ]
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\7 F* q. U2 X; o reset-ticks
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1 J$ c c, O7 w: R- s: J/ G;; Initialize the global variables to appropriate values) ]9 }# x! J9 ]4 H
to setup-globals& P8 Q' Q8 L2 I; B; m1 g* p. v c
set current-light nobody ;; just for now, since there are no lights yet3 Y ]9 \* N$ x7 C9 `/ F
set phase 04 X6 y: q; w# A; s
set num-cars-stopped 0. s* O: K9 c- U) l1 w* M; C
set grid-x-inc world-width / grid-size-x
: H8 o& |& S+ R9 G set grid-y-inc world-height / grid-size-y" a: |- H- @" 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, E/ r) I4 [+ [) G, G! O
set acceleration 0.099- K' u: V2 {0 B- b& o
end
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$ D: a% C7 ^- };; Make the patches have appropriate colors, set up the roads and intersections agentsets,) b# T( C1 H' k! t9 Z
;; and initialize the traffic lights to one setting0 r- ~- g1 P# a( t2 V+ i/ a
to setup-patches
+ w& Q7 I; r9 [! S+ l) z ;; initialize the patch-owned variables and color the patches to a base-color& Y4 t$ }# C2 @ ~8 h
ask patches
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set intersection? false
X+ ]# ~) V0 h0 v set auto? false
' S* k) G8 B- J/ `; D: j0 R% K7 O set green-light-up? true
! b% [( N( P" q set my-row -1
9 x( x' ~. _) B! F, k& i set my-column -14 h1 } @+ s* W9 S. f
set my-phase -1
/ H# K. }# w3 X0 `, K7 W; h' ` set pcolor brown + 32 F9 `, U: B' d; i0 a
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& m4 ^# y" u, s {' p3 O ;; initialize the global variables that hold patch agentsets
- D9 |* d4 m9 i' Q) J: Q2 Y set roads patches with1 F7 ~6 p% x+ Z2 `) q. @
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
) v2 n2 S- o- Y" F' A# N (floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 C t4 I7 y, \: R; A% y
set intersections roads with5 g# j' A( O0 _+ s) K
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
+ q4 u" `( W8 L: ^" r (floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ o/ c6 ?, L! r2 Q' U
. J7 q B0 H+ Z6 D6 f- n, ?2 `: D ask roads [ set pcolor white ]
$ N8 b/ r8 X+ Y1 Z setup-intersections: Z1 w ?; C( n: m0 }7 B& M+ j
end8 \2 Z' U- T+ m# D* I
其中定义道路的句子,如下所示,是什么意思啊?
# _3 {- n& }: Q$ w6 J set roads patches with
( D/ a0 u7 D5 u) U: q6 B [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
, Y, y. d, }9 ^& G5 u (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
( {, w' v+ y8 O1 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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