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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。. f% N' u; _! O8 V4 I$ c
netlogo自带的social science--traffic grid这一例子当中,8 \# w9 ~2 D. z1 P* H" o
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction+ j& u' A( K/ O$ `7 e3 j5 p% p6 X9 F
grid-y-inc ;; the amount of patches in between two roads in the y direction
1 S: @& F' q% ^ `" R7 j% [ acceleration ;; the constant that controls how much a car speeds up or slows down by if& K; d9 ?" a g; j! [
;; it is to accelerate or decelerate
9 d& L/ Y l% A# h7 M phase ;; keeps track of the phase" J; v5 w0 i. X5 U
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
# }' `' `* x% e* x current-light ;; the currently selected light6 L9 `# O2 N! I( o
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;; patch agentsets
" W. H. E# z% d& q( t; F& c intersections ;; agentset containing the patches that are intersections" \$ ~% W. o5 e" _
roads ;; agentset containing the patches that are roads
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turtles-own. {# ~ z7 q! L! E" t5 I5 u
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speed ;; the speed of the turtle$ c1 J0 c& |8 Y+ l
up-car? ;; true if the turtle moves downwards and false if it moves to the right3 T1 X6 s8 E6 L; o' f
wait-time ;; the amount of time since the last time a turtle has moved
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; r B# ?) p& ?& {& X& Z2 Fpatches-own9 N, W* `7 x$ ]- y
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' [/ q7 _6 m( [# J) s intersection? ;; true if the patch is at the intersection of two roads
6 i q* g( v/ A2 d6 m green-light-up? ;; true if the green light is above the intersection. otherwise, false.5 I l) G6 `8 x/ x- s# e
;; false for a non-intersection patches.0 y7 S b: x! R
my-row ;; the row of the intersection counting from the upper left corner of the
, O& l0 N5 [$ L ;; world. -1 for non-intersection patches.! p$ M. ^; Y* t# v2 Y- i" x
my-column ;; the column of the intersection counting from the upper left corner of the
( _& ~! I: b& H+ x4 y; j ;; world. -1 for non-intersection patches./ K$ a+ f! h2 Z. R. H' m2 I- R
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
& Z. K1 y* f ^# U9 z auto? ;; whether or not this intersection will switch automatically.4 T+ X; R1 F' T% k' F+ F! Z. y
;; false for non-intersection patches.
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; j4 X, G. u8 ?+ i& O0 I: R;;;;;;;;;;;;;;;;;;;;;;* ~$ N1 S% s' F1 s& s9 v
;; Setup Procedures ;;/ J) W, @0 ~8 G, u
;;;;;;;;;;;;;;;;;;;;;;
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8 P! Q( s' n; N5 `;; Initialize the display by giving the global and patch variables initial values.7 j3 F7 a" w* Z0 ?( K/ O
;; Create num-cars of turtles if there are enough road patches for one turtle to" [* R8 h1 X4 o$ Q+ S
;; be created per road patch. Set up the plots.
, i! S; T1 u0 e8 ?to setup
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setup-globals" g3 ?4 t$ ~1 A, [( }& D
1 T) w6 G) b( s ;; First we ask the patches to draw themselves and set up a few variables
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make-current one-of intersections
& j6 h; B& X* A, {' O label-current
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' J* M: J" v! Z {; ^, U4 S set-default-shape turtles "car"! ?$ E3 ^# B2 ]( b- q1 r5 F
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if (num-cars > count roads)- ?% S q3 u. p& Y9 v& S, |
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- a- { K5 X9 p4 j4 D1 ]9 E& U: a j user-message (word "There are too many cars for the amount of "
( p: c' i8 L6 l "road. Either increase the amount of roads "9 w. f+ j2 S5 a3 \
"by increasing the GRID-SIZE-X or "& @( J4 U! h C$ T8 z
"GRID-SIZE-Y sliders, or decrease the "5 j$ y- x% @- a9 }/ z
"number of cars by lowering the NUMBER slider.\n"2 P! u# \ y/ z3 }
"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-color6 E+ R# J9 ^5 T
crt num-cars
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setup-cars" Q$ b* {) q* H% p# S5 {6 }
set-car-color
0 R2 X9 A r( P record-data
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" ~, ]4 J" o# s& r3 ~$ C. @# x; w ;; give the turtles an initial speed
: l4 I, k6 \) T L ask turtles [ set-car-speed ] p+ y* z8 p0 h
) h" T% z6 U. z7 v! P" j4 l3 X: f reset-ticks
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: s$ w" v5 u; h; b4 V;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet. x+ Y- H3 h+ N
set phase 08 O# |& o9 n5 |" _, B/ O
set num-cars-stopped 0
0 G! R8 d- f3 }2 p7 l) ~: S% h2 |* t set grid-x-inc world-width / grid-size-x
: n& f$ S% U2 E1 p set grid-y-inc world-height / grid-size-y
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/ M' g* X8 [3 m9 I- T6 o ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary( ~7 s. U8 T: Q. _6 n! l
set acceleration 0.099% E' }' ]! Z9 y& d
end
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* K) z0 l3 [8 [;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
! ]# h5 B0 _- {, f3 H" p9 U# C;; and initialize the traffic lights to one setting
# J% a& K' N1 ^, h$ x! P# Mto setup-patches
( x2 a1 e% g2 a' w2 T9 R+ y# ?: Z ;; initialize the patch-owned variables and color the patches to a base-color
/ b! V% _& I$ C9 ^; G. F$ s ask patches
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6 g9 N4 k7 B% r5 y set intersection? false6 n+ d/ \9 L0 X7 ~6 Z
set auto? false
$ C9 G. g; {/ f* ?! W set green-light-up? true, y+ p% f7 b% n0 h+ I( K* j8 H3 S
set my-row -11 Z) F; ]+ F% G: q
set my-column -17 k" k0 o; Y8 {2 w
set my-phase -1: ^% n% k# l% m% V) N
set pcolor brown + 31 M* n3 J; U. n; _- p6 u
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;; initialize the global variables that hold patch agentsets, w, D# ^7 U7 o& a. F7 J% z
set roads patches with# o% U d& T3 o2 ?
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' S6 d' A+ u7 R- V
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 R- ]" u, M* N r( S
set intersections roads with
+ [% @: q1 W9 ]6 f7 B, W [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
6 N* ?1 w7 f" q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 W7 r* T% \3 Q
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ask roads [ set pcolor white ]7 [2 g4 g2 d1 l5 Q; b( A& ~; M
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?% r* r) X: @ {8 w. T" a
set roads patches with* ^% M. m' v9 h' Z5 X
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
2 [! E9 }1 C; L* x! d4 d. i (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
5 Q+ {! w# o# Q! w6 [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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