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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。
/ }1 m" d8 w x+ Lnetlogo自带的social science--traffic grid这一例子当中,4 e+ P$ N" F" u3 _* o, \& S6 a
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* f- ?0 H$ T1 z grid-x-inc ;; the amount of patches in between two roads in the x direction# W7 w2 ~# o) c" p# m% l
grid-y-inc ;; the amount of patches in between two roads in the y direction
4 x. O/ x( z0 Y; b acceleration ;; the constant that controls how much a car speeds up or slows down by if
8 Z3 ]. b s! o% ? ;; it is to accelerate or decelerate" z2 M* H) r1 ]' Q4 P8 w1 m
phase ;; keeps track of the phase7 o$ e1 d9 m8 Y0 p$ }# P) }6 t
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
/ ?4 U& O7 F% d; M" _ current-light ;; the currently selected light- J5 d0 u) t# z5 ]: _, C
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;; patch agentsets
8 N7 J D: X7 S5 _ intersections ;; agentset containing the patches that are intersections# T$ r E/ T7 S) O8 c
roads ;; agentset containing the patches that are roads
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. n- w; k% A# ]turtles-own
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$ e. m. F! k2 c. e' I: G9 ~) ~4 T speed ;; the speed of the turtle
0 }$ l! B: A* X) {+ J up-car? ;; true if the turtle moves downwards and false if it moves to the right
5 b7 T1 y9 N# [$ o( i* P3 { wait-time ;; the amount of time since the last time a turtle has moved
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/ [( Y9 G& l/ a: ?( h, j) l/ a8 dpatches-own0 \9 A4 r( G4 R+ @6 y; z# `
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intersection? ;; true if the patch is at the intersection of two roads
1 W" j! ~! _% p3 W' H, B. f green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! T! B* M' o& j7 N. G ;; false for a non-intersection patches.: Y. R' @' Y F0 \: Y
my-row ;; the row of the intersection counting from the upper left corner of the# h. _) M: _) A4 P" N
;; world. -1 for non-intersection patches.
+ e+ j+ p' m7 m2 }. i4 T U: G; p my-column ;; the column of the intersection counting from the upper left corner of the
1 I0 |2 J8 ]# ^- ], c) j ;; world. -1 for non-intersection patches.5 d! e' p% D: S3 K R+ n$ ^* h8 @/ |
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
% K- r+ P0 _4 j/ J9 M/ y# y6 s# | auto? ;; whether or not this intersection will switch automatically.0 F/ \. y/ _6 d# a+ v) z
;; false for non-intersection patches.. [& [5 b( W. [5 g( D
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;;;;;;;;;;;;;;;;;;;;;;
2 Y5 m5 j) N9 k; b6 }# `;; Setup Procedures ;;' G, ?/ @8 d; r/ w$ X9 m- U
;;;;;;;;;;;;;;;;;;;;;;
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( g/ l; j5 [, C# \1 y( K; h1 J: \;; Initialize the display by giving the global and patch variables initial values.+ p& s/ z( z K+ |
;; Create num-cars of turtles if there are enough road patches for one turtle to. J9 k; P0 k9 b; Y7 S
;; be created per road patch. Set up the plots.
6 P' g7 V3 X- Z2 L$ wto setup
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5 t ]9 {: _1 l7 A- b# p( e0 [ setup-globals0 ^' J9 A8 Z% W* x3 Q2 }; F6 k$ M
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;; First we ask the patches to draw themselves and set up a few variables0 H: D9 \* q. F/ g# [, [8 d' I- V H
setup-patches
4 S3 \# _( O4 P! h z6 [, e make-current one-of intersections+ H+ g7 y$ V2 Z" |* p4 T/ S) h
label-current' o6 M y3 ~+ u
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set-default-shape turtles "car"
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" {4 x c/ a" @1 L: F0 ]+ L if (num-cars > count roads)* y3 B" N5 k% t4 |
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2 s/ c+ \& I, r user-message (word "There are too many cars for the amount of "
! u: b. g' Q9 @" n3 p0 \; Y5 u "road. Either increase the amount of roads "
s* z6 }* o$ d$ e) y "by increasing the GRID-SIZE-X or "
/ b' _: O9 O! T) d4 Z* F+ D "GRID-SIZE-Y sliders, or decrease the "
1 v* I _. s7 h# P! i$ j4 m' ?" r- Z "number of cars by lowering the NUMBER slider.\n"" L+ W5 s( Y" F8 Q8 y; V5 I
"The setup has stopped.")# E: g" d; K A: }
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
0 U5 s% N! O, X$ P4 x crt num-cars8 t8 n3 S7 }% g; a9 X
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1 ?5 P0 m, Z; ]3 E1 M# Z4 y8 N$ ] setup-cars
2 s: g5 J' h0 r3 O set-car-color' u' f4 F& v3 p1 g
record-data/ }' D1 ?& l Z0 G5 }
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;; give the turtles an initial speed* {& ]* S- K$ ~% r1 p3 a* Q8 n, @
ask turtles [ set-car-speed ]$ v. E% O$ p: o, z# A8 \( v: F
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reset-ticks
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;; Initialize the global variables to appropriate values
( c7 i( r8 s! C$ }0 v& q: eto setup-globals/ N" n; M! |& \* u+ C) y
set current-light nobody ;; just for now, since there are no lights yet
( G3 Y/ c0 m3 N/ `9 j, v9 ?. k. O set phase 0
: ]1 e; L5 r: K set num-cars-stopped 0" o6 D) S* z& F" t, b# c
set grid-x-inc world-width / grid-size-x
5 Y3 F! i% q9 B) s set grid-y-inc world-height / grid-size-y
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+ b9 K y: _7 f8 J9 m ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary O+ A9 ~; x9 p8 ?5 D; }
set acceleration 0.099
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7 I- j9 a! @4 L;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
! q4 Q& [& O7 L- h7 M4 M3 V; |;; and initialize the traffic lights to one setting; p7 W. e! x9 |% F
to setup-patches
3 W2 i: y x4 |2 `- q9 g; z5 m: {0 { ;; initialize the patch-owned variables and color the patches to a base-color5 d- \2 P6 `& t# A+ @# c" V
ask patches
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6 h. ^7 Q A: q( a1 A% u/ o set intersection? false
G5 U8 k7 i! F8 a7 ^ set auto? false
) ~+ V. k# q2 @6 l" r% A i set green-light-up? true" e I) h' r! t5 P
set my-row -1
, K! b* ~4 E) w+ R3 G4 w7 ]0 ] set my-column -19 \5 i$ u2 W+ I7 n5 G
set my-phase -1% R, D" l, w/ U1 j5 W
set pcolor brown + 3
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# X0 N2 ?* p) e# i6 x6 @9 m ;; initialize the global variables that hold patch agentsets
8 g7 ]7 `- b$ B9 @3 ]. i set roads patches with
( |& z5 H7 c5 F) w( ~2 }" m, j. U [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or+ W4 G6 b; n: J4 T) m5 D0 `7 ^
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 z* Q% F B9 ^: m
set intersections roads with
# C7 M! ]& b$ I4 I# p' d7 u5 f [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and0 o$ C' i% X/ ]2 G: `4 }8 V
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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" D6 l" |$ w( L/ V( z ask roads [ set pcolor white ]
& ~) k+ C$ Y6 l6 M7 t3 o7 W setup-intersections# P% q0 B# |5 D' r/ i: }
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其中定义道路的句子,如下所示,是什么意思啊?/ O' l% ~. j. c1 @
set roads patches with
. ~0 m- k( \' q: k [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" f3 h) D2 N0 g$ \1 K1 w1 V' P (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
- o) w4 v% j/ S; o. V3 `9 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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