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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。
4 Y6 o! w. q$ Y A, Cnetlogo自带的social science--traffic grid这一例子当中,
( e6 a' G/ E+ @1 {' Vglobals+ z' F; X1 j( |) e( s0 |$ N+ A
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grid-x-inc ;; the amount of patches in between two roads in the x direction
! Q# I \/ W/ {6 V: | grid-y-inc ;; the amount of patches in between two roads in the y direction
3 r) L/ _% m- k% T% }7 S acceleration ;; the constant that controls how much a car speeds up or slows down by if: n* d# s5 f+ \# t& g- M
;; it is to accelerate or decelerate: U6 {) [7 j. b% l. G# k; l' l
phase ;; keeps track of the phase" W! V/ O, ^5 H+ y* B0 ]
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
% P: V1 u9 L+ N& b- ?, c$ ?. d current-light ;; the currently selected light# E# Q9 s. b/ `+ `
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;; patch agentsets; _6 B* [# ], Y& a/ q
intersections ;; agentset containing the patches that are intersections
. f( Q1 n! [( A& z7 g; { roads ;; agentset containing the patches that are roads! y% z7 Q& |3 R0 M8 U7 {1 z$ q
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! z4 r" P6 m# @0 M: A f) B9 q7 Uturtles-own
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: b$ Y! C: O R3 P6 g+ @ speed ;; the speed of the turtle
5 R. f. ~. V' ^ up-car? ;; true if the turtle moves downwards and false if it moves to the right* q& u; } T& M0 B; Z& w
wait-time ;; the amount of time since the last time a turtle has moved
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& C/ j. J1 w, \; C2 {+ A! Upatches-own
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intersection? ;; true if the patch is at the intersection of two roads
2 u v6 N/ [' W5 S+ G; x1 T/ ^ green-light-up? ;; true if the green light is above the intersection. otherwise, false.+ b7 t7 V( F; g/ L1 G4 h. |3 A
;; false for a non-intersection patches.
4 }9 ]6 G1 Q# A4 u# j! g/ s. d my-row ;; the row of the intersection counting from the upper left corner of the2 G6 U* F3 k/ f6 J
;; world. -1 for non-intersection patches.) o1 m4 W' D. I. L
my-column ;; the column of the intersection counting from the upper left corner of the
. V- [, s' N( {, Z4 W3 I! n ;; world. -1 for non-intersection patches.
, F6 ~/ o* n" F my-phase ;; the phase for the intersection. -1 for non-intersection patches.7 L" _' m: H! Y
auto? ;; whether or not this intersection will switch automatically.6 Y. H, e7 ^( m0 k" t T+ j7 T
;; false for non-intersection patches.
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5 Z8 I8 g( [4 V5 m;;;;;;;;;;;;;;;;;;;;;;
0 `7 ^; Y1 b( k& s- c;; Setup Procedures ;;
4 c* _ }$ U" c! }. e' x;;;;;;;;;;;;;;;;;;;;;;
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* I9 J' a8 `3 e; p$ ]3 F;; Initialize the display by giving the global and patch variables initial values.
( X7 ]6 {, W2 Q! c;; Create num-cars of turtles if there are enough road patches for one turtle to: m/ ~2 F7 v! m, }
;; be created per road patch. Set up the plots.# s3 D# f* e* d# L& I
to setup4 v4 h, ~2 D0 L/ C! }- h# X7 r! o2 l7 U( g
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setup-globals
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" }5 e9 y: l# F* ~% x5 N ;; First we ask the patches to draw themselves and set up a few variables
4 h% M! c& O5 R/ ?9 n8 h( ` setup-patches* P, v Y5 q( w& k2 Y
make-current one-of intersections
( b9 q. _( }( r- A% c6 S label-current
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set-default-shape turtles "car"
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4 \# \2 R y2 R if (num-cars > count roads)* e0 w, K+ h( v/ B* I
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- l/ Q; N+ f ~! a user-message (word "There are too many cars for the amount of "3 a) V& N% D' F$ K
"road. Either increase the amount of roads "
' L# p& P8 W9 W+ G" @' ] "by increasing the GRID-SIZE-X or "
" b6 o% Y b$ Z; k "GRID-SIZE-Y sliders, or decrease the "$ x+ x4 G( R, s# ]& Y, G
"number of cars by lowering the NUMBER slider.\n"
0 ?, n% K4 L) J+ m "The setup has stopped.")* p+ p0 J( K" }
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
8 f" P( }% o7 A( c8 @% C crt num-cars
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setup-cars" z7 W& Q9 W8 e( G! B% X
set-car-color0 B6 E4 u2 _8 q' S2 N6 L3 H- P6 e/ H
record-data
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;; give the turtles an initial speed2 d4 P$ D) P* e0 d5 Q) |
ask turtles [ set-car-speed ]
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/ @1 V* s* X" F" Y* _ reset-ticks
3 @- Z- ^2 ]. U1 nend
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2 U$ R0 e, s m4 B;; Initialize the global variables to appropriate values9 E% o. M" y9 S
to setup-globals
; I: U3 ^( u6 u3 D, @3 W5 m; u set current-light nobody ;; just for now, since there are no lights yet
, x4 m1 N. n/ t L3 y set phase 0
$ b) n% i$ V; g& M* @ set num-cars-stopped 0
) ~, q7 C' k0 U4 }) l! T set grid-x-inc world-width / grid-size-x
" v% z" B5 |# _1 B6 k2 N0 t# O- m 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+ h1 a& u% V7 b% P, S
set acceleration 0.099# K4 M* A5 Z4 z" p
end6 ^$ W7 c5 Y" V4 b) s9 Q
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,% Q: g6 O0 u. H
;; and initialize the traffic lights to one setting
4 `. Z9 z$ R5 A' o' f9 o* tto setup-patches3 l2 q) ?- K- a( X: Y
;; initialize the patch-owned variables and color the patches to a base-color- N$ L. g" E+ i5 @2 F1 t4 S+ V
ask patches3 ]3 D! v% G6 G) ?8 _
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3 } j+ p6 i8 H* f6 `% x& \ set intersection? false: u# [0 W1 R$ j& a" k
set auto? false
. o) ^+ b4 D; t9 D set green-light-up? true
8 P/ _; z3 G! N6 X set my-row -1+ j3 o: N$ _) b3 h' v
set my-column -1 u2 `5 R. V: r8 n) U5 b) h
set my-phase -1
" |1 m8 I8 [: c. o9 E8 s" k set pcolor brown + 32 [4 j! d8 F0 d: o: l- }
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: A* ~) e* z0 R* D7 P' q9 I; z ;; initialize the global variables that hold patch agentsets/ C9 L8 Y6 f J m% ?( Z
set roads patches with
" ^/ l% b9 p9 v1 }+ | [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or9 w- A( @4 s4 X. M4 A- M
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ D# }' Q. ]9 ?
set intersections roads with1 t# a4 D2 D- p9 P7 a0 N& t7 ?
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
0 z3 D1 Q& U/ C; h q' | (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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x# ?: Z/ f% I @; f P, a ask roads [ set pcolor white ]
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其中定义道路的句子,如下所示,是什么意思啊?) m9 \5 z$ X, h1 K5 C1 _" |2 q
set roads patches with# L% v l, J) w
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# l# h3 j$ B* Q/ m C4 z3 @ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
% H, F# \' H. b) @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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