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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。
5 x0 i( N. ?) N6 P5 D2 ^. Qnetlogo自带的social science--traffic grid这一例子当中,
- K: e& @/ X! [globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction3 n$ B9 b; P5 T* P4 G
grid-y-inc ;; the amount of patches in between two roads in the y direction( O2 [1 G! |, {7 b8 h
acceleration ;; the constant that controls how much a car speeds up or slows down by if! H/ E9 N2 H/ p/ M2 @% M' K
;; it is to accelerate or decelerate
: m3 R a) K& G+ K phase ;; keeps track of the phase4 |( v. B7 ]8 G6 S8 a
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure& I% U5 L& e6 R. A, S, A4 y
current-light ;; the currently selected light
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;; patch agentsets
! J, t$ P; w# r+ P. V intersections ;; agentset containing the patches that are intersections
# Q7 E7 ?8 [/ w1 d2 u; _ D roads ;; agentset containing the patches that are roads9 K6 j2 P$ g4 v( c+ F2 t. D( r( [
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& a) ?0 e2 j, z5 Vturtles-own1 Q6 Q- }$ L9 s; I) m* B+ t
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speed ;; the speed of the turtle8 A& I0 d& V- Z- o
up-car? ;; true if the turtle moves downwards and false if it moves to the right( f# x0 P4 N/ X5 l( B! g* a8 {
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own x$ F$ r3 z3 ~" ~: ~4 ^
[
& u( P2 Y; Y. {" Y1 Y. G* W+ { intersection? ;; true if the patch is at the intersection of two roads
! W4 n7 B7 c4 e9 g Y green-light-up? ;; true if the green light is above the intersection. otherwise, false.
+ Z/ v% c0 {& _ ;; false for a non-intersection patches.
9 ^1 S. \5 q5 {* e my-row ;; the row of the intersection counting from the upper left corner of the/ T: J' {) e5 v' @+ N$ ]
;; world. -1 for non-intersection patches.& [% n, k8 P2 w' u4 b1 O
my-column ;; the column of the intersection counting from the upper left corner of the
e6 O+ a( n) `- z% q: k6 d, {5 V ;; world. -1 for non-intersection patches.& K9 O3 F# g! s
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
" x. b0 K/ I1 E. Y+ j ]* J auto? ;; whether or not this intersection will switch automatically.
9 t2 h' [1 U' W1 M0 b+ D( u3 d ;; false for non-intersection patches.
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1 O/ M. J. u4 v( `' _;;;;;;;;;;;;;;;;;;;;;;
) I, i- T. m( b2 u3 k;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.* I/ D( p. I: V; p' P3 \" p& F, o
;; Create num-cars of turtles if there are enough road patches for one turtle to
|! T) E5 T4 |- \3 S, E;; be created per road patch. Set up the plots.3 ]/ K9 c# P! s) H4 M
to setup( V- l+ a! }' _" d, s
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setup-globals+ I8 y$ ~. S! x# V8 X: I& B7 m
. H) U( b* m$ X% q5 z. G0 Q0 O$ H0 Q/ f ;; First we ask the patches to draw themselves and set up a few variables
. P3 O/ c# A# r1 h setup-patches
& g7 ]- v8 ]5 t. P+ f, v make-current one-of intersections8 g9 t( ]8 c- z' f8 w
label-current$ u' e5 T7 q) f% j1 j
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set-default-shape turtles "car"
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if (num-cars > count roads)! @ n# ^7 U q# a: n
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& }" g4 [" d% p0 e user-message (word "There are too many cars for the amount of "
8 V+ m4 M! X N+ G2 B6 R5 r" Z "road. Either increase the amount of roads "
& G; Z0 _* X( l3 C" L; G "by increasing the GRID-SIZE-X or ") B; g; R# I; u( ]& k! L' l# O
"GRID-SIZE-Y sliders, or decrease the "
# e0 L; W. C. B g; C* d* [4 ` "number of cars by lowering the NUMBER slider.\n"
& b) Q' [5 K/ O2 ?' h3 i# n4 E; n, ~7 K "The setup has stopped.")( y R- b, m( \ _9 m) ]
stop/ Z# Y0 l6 e$ z" s9 F% Q: a3 W
]
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color$ S9 B+ }" U# T/ z% A) ~( x
crt num-cars
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setup-cars
. H6 `1 |" x1 X set-car-color
1 V) W e& D7 h* e: N record-data4 ~) f9 M5 I! d# |/ e
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" A; D6 m, K4 |6 \$ {3 { ;; give the turtles an initial speed8 _ `( C2 }7 r( [7 K
ask turtles [ set-car-speed ] l9 g& @6 O5 @2 x
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reset-ticks1 A2 a, c, |) W: |6 m
end, }3 S' s. ?4 t& a
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;; Initialize the global variables to appropriate values7 B6 x: a8 {4 r- A9 l
to setup-globals0 v5 K. L" N$ t
set current-light nobody ;; just for now, since there are no lights yet! l8 y& b/ S/ o# W
set phase 0/ x% C4 X- r/ ~& O! G" W9 y6 x
set num-cars-stopped 0 n a# e9 O* ^
set grid-x-inc world-width / grid-size-x1 d% P, G, ~- `. d8 U8 Q
set grid-y-inc world-height / grid-size-y6 [' T& n% c! w Y- Q! i
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary' b. Z K* q' [) k
set acceleration 0.099
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- V3 ^3 J% E% C" l! a$ _;; Make the patches have appropriate colors, set up the roads and intersections agentsets,; c9 t! { `# A5 U6 U2 I8 E
;; and initialize the traffic lights to one setting& d: w& E6 w; c6 `; X: j
to setup-patches
, t+ [4 q+ G5 E0 J# \9 r ;; initialize the patch-owned variables and color the patches to a base-color9 {$ C- ]' n: g. o) l
ask patches
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set intersection? false# [& z% h4 O4 q8 O( ^5 E$ s
set auto? false/ T) B W5 @+ a) h1 X+ W
set green-light-up? true
7 Q2 F% [, N7 T+ M set my-row -1$ V( T' w0 k) k0 s. ]
set my-column -10 S$ C4 y' @+ b. q! l: A+ O
set my-phase -1) @- p8 t9 Q- u" w/ X
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
" [+ H3 u! B; O* s set roads patches with
: }! W0 W: {' `8 q) B8 v' U [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# ^% u5 g3 H% @ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 }# g. f1 v* z- V/ P0 f) ` set intersections roads with' Z" _# g5 ^; B3 s0 t# F
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
/ x- _! n4 }2 M5 ?; u) i# u) _& o (floor((pycor + max-pycor) mod grid-y-inc) = 0)]( E& e* N4 _' W" y/ ^& S
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ask roads [ set pcolor white ]" o9 T9 v7 d( J' h8 P
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?7 _+ N# d- K. f
set roads patches with
9 Q1 X, @0 e# R) e4 i [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or5 _& P+ ?% a+ y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
" O/ S* b, i5 V8 L( U$ ?% g, 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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