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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 F$ H1 |4 `1 Z7 W3 `3 O c
netlogo自带的social science--traffic grid这一例子当中,
1 ?8 u' F9 k t# I( j; l6 eglobals- V( Z! P$ p9 ?$ Z6 P5 w L
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grid-x-inc ;; the amount of patches in between two roads in the x direction0 t. ?$ d- g$ j$ X8 W2 ]5 }
grid-y-inc ;; the amount of patches in between two roads in the y direction
# V% O/ m7 ~- w! k5 \* _4 [ acceleration ;; the constant that controls how much a car speeds up or slows down by if) T( f3 q* O0 A/ N4 c: ^# U
;; it is to accelerate or decelerate
% d- Q* x/ ^% | M# n# F9 N phase ;; keeps track of the phase9 B5 r% m( ^( w0 j
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure D5 \' X. \* h& R* C
current-light ;; the currently selected light& q" s/ D$ Q0 F8 q+ T
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;; patch agentsets
h6 S8 `2 y6 U. t9 e intersections ;; agentset containing the patches that are intersections+ Q; A! B' {& _( Q8 B0 ]
roads ;; agentset containing the patches that are roads9 C N. M3 L# h# `- q
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. @; E2 S; G& d( {( E8 C ?: q1 ~0 lturtles-own
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speed ;; the speed of the turtle
" u3 f: }* X R& E: q | up-car? ;; true if the turtle moves downwards and false if it moves to the right
8 y' G0 w+ O$ _4 Y) N# S3 ?( M/ N# m wait-time ;; the amount of time since the last time a turtle has moved
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patches-own) x/ b1 C" I9 n* Y1 Y8 B
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intersection? ;; true if the patch is at the intersection of two roads
& K. ~ A2 e7 R" x green-light-up? ;; true if the green light is above the intersection. otherwise, false.
9 b( J/ C. P4 h: S ;; false for a non-intersection patches.
. F# @+ x7 w4 ^" `* R5 [ my-row ;; the row of the intersection counting from the upper left corner of the
9 _: J9 N- P& ^5 d+ Z2 [ ;; world. -1 for non-intersection patches.* }: A6 ]. ^# G U$ d
my-column ;; the column of the intersection counting from the upper left corner of the' V- K0 K( H4 x
;; world. -1 for non-intersection patches.# l/ L0 W# f/ r' [1 Z. q
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
! y: S2 A* J. a$ X' g1 l auto? ;; whether or not this intersection will switch automatically.
0 p4 [8 V! E# d( a3 n ;; false for non-intersection patches.$ W+ P9 y& G! n. F" t8 S
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/ E" [' ~+ e: \( O. E+ u; L% a;;;;;;;;;;;;;;;;;;;;;;# D2 u6 _- S2 i- J2 \; m
;; Setup Procedures ;;5 n7 g9 G* z% n& [
;;;;;;;;;;;;;;;;;;;;;;" F$ w! `0 y. b) R( z
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;; Initialize the display by giving the global and patch variables initial values.
/ t/ P2 M; k! {- p& D;; Create num-cars of turtles if there are enough road patches for one turtle to
. C- @) ^ v) y5 ]" i;; be created per road patch. Set up the plots.
1 }* u# {* u! y/ d$ j2 Ato setup0 y! t( G/ [, E/ ~8 }
ca
5 ` y) O4 k- e2 o setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
4 o5 r8 C0 b; }4 Z8 ], c: i setup-patches
+ C7 j4 f8 i2 Q9 ?7 @$ Z make-current one-of intersections
% _; J, z7 ~+ ~( T: w9 ~6 c3 { label-current5 d; A* z* }# G- w8 N
8 Z3 l) t9 m1 ~0 y* D/ k, r set-default-shape turtles "car"
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0 I' X# w& [8 C if (num-cars > count roads)
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" e; p& j+ D$ X7 y$ G: Q! q user-message (word "There are too many cars for the amount of "4 t, E( T M. B( H$ S9 W4 Y
"road. Either increase the amount of roads "# n6 m9 {& K5 k* \, j
"by increasing the GRID-SIZE-X or "
$ i4 @+ {' s, o7 M" z" @% G "GRID-SIZE-Y sliders, or decrease the ": G) s9 E0 J. c8 @- J
"number of cars by lowering the NUMBER slider.\n"
: p1 G5 O- c6 ?3 D5 N& e "The setup has stopped.")
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
& a* k; I# Y- n( ` g crt num-cars
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2 i7 G' x0 f3 i F+ U setup-cars
1 Q2 @5 |2 x2 p! r: `2 p5 u4 } set-car-color
% ]/ F/ T' }5 V; G; X) K: [ record-data: a8 t; E$ N$ B; g% P. h" U- ~9 _
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;; give the turtles an initial speed
# b/ r C8 J, U) I3 X0 S ask turtles [ set-car-speed ]4 l' h( d# h& b* C
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reset-ticks
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;; Initialize the global variables to appropriate values
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( Y% M" V: g* D7 W set current-light nobody ;; just for now, since there are no lights yet7 Q& w Q) Z! x8 U! O( k
set phase 0- g( a9 B4 }1 o) v! i/ t, z4 u3 y& T
set num-cars-stopped 0
6 ^( y( U+ c f: @$ y, ^ set grid-x-inc world-width / grid-size-x! E J5 f# N% ^' e( X c/ F) u0 ^
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/ p/ A! n1 @- C3 O7 w
set acceleration 0.099
' E0 A7 l! q6 K4 i2 E/ zend
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$ Q' l+ o$ Y9 L2 U0 E( X;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
* S1 m# |* a. H0 D8 p% i;; and initialize the traffic lights to one setting
+ h- Z4 a& h9 n% ~) X2 }! oto setup-patches
" f& Z% p0 w, I, {7 [6 s ;; initialize the patch-owned variables and color the patches to a base-color& B+ E7 h& F5 a) @5 i
ask patches
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set intersection? false4 J% v x+ E$ R# b3 V
set auto? false
& B, S4 u. ^2 n; d$ j! u set green-light-up? true* Q/ _1 p& K' E& L' t+ i8 n
set my-row -1) l( y# n4 \; P' F7 }6 m
set my-column -11 k2 _7 [. Z, U, |# u, N! s- L
set my-phase -1
' \* C$ \. D/ `, c set pcolor brown + 3" E( l) s: ~& J% W9 ]2 @" L! ^
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0 ~4 l/ H9 n' A" p2 s P5 Y( w* D ;; initialize the global variables that hold patch agentsets
; E( c( X- X: t* H set roads patches with
& \/ o D* c: u [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
3 s7 B0 H0 r* m/ m (floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ E9 E d( S D! u* q: H; U2 M
set intersections roads with
1 f3 _. E0 q! W6 u. u [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and6 t/ D" C; _; ~0 V7 O/ b& I
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]% x1 d7 J Y, c/ l8 i
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ask roads [ set pcolor white ]8 U" t+ }$ T+ R. W
setup-intersections, M) {6 x' \) b9 b
end+ x$ S5 _2 J& F
其中定义道路的句子,如下所示,是什么意思啊?. g0 A B: F9 c3 D: m
set roads patches with0 \2 x0 o9 y' f1 Q, q% Z: E5 z+ I
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or. r9 t, d2 @! }0 T5 _
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
# l5 ?/ _& }& r' e) _! s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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