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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。
( {% u6 e0 x! {" d2 Anetlogo自带的social science--traffic grid这一例子当中,
% q, B9 @3 c) b/ E0 Nglobals
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6 S1 n$ v. U2 N! F7 }6 i grid-x-inc ;; the amount of patches in between two roads in the x direction+ X; o" Y3 F& \
grid-y-inc ;; the amount of patches in between two roads in the y direction9 e- B; J+ z$ u; c
acceleration ;; the constant that controls how much a car speeds up or slows down by if
+ {- R) n! t; p2 P. T; [$ ^) N/ k ;; it is to accelerate or decelerate
2 h7 _# r5 j* b phase ;; keeps track of the phase# V! U' d- l- Y' o& p
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
" L! c& u5 J( M i: {* L7 D7 |5 B* ] current-light ;; the currently selected light
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;; patch agentsets
3 ?8 w" j) Q4 e( X7 H2 t# b2 @ _ intersections ;; agentset containing the patches that are intersections8 Y- d/ p# D6 C, G
roads ;; agentset containing the patches that are roads1 N/ Q$ d4 |" T, n
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turtles-own
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j1 s# c/ [" z( s% E% p3 h speed ;; the speed of the turtle8 \/ b! m. Q& m% \; n
up-car? ;; true if the turtle moves downwards and false if it moves to the right
( Y+ ~ B) n3 P3 {- E. t wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads7 ]5 I' y1 k* A
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
, n+ N3 ~7 Y/ s4 k9 ~" m ;; false for a non-intersection patches.
' v% K* j# y! L2 C6 ^9 S/ K my-row ;; the row of the intersection counting from the upper left corner of the
* y: d) ?( l- g9 ^3 r; @5 } ;; world. -1 for non-intersection patches.4 m* f1 w& o" _% t9 K- Q8 ?$ M
my-column ;; the column of the intersection counting from the upper left corner of the9 v) f" }3 H. ?, I
;; world. -1 for non-intersection patches.* n9 K) R1 ~* Q5 ~
my-phase ;; the phase for the intersection. -1 for non-intersection patches.' Y+ B. U* |; _1 S. {$ c ]/ M, t) d
auto? ;; whether or not this intersection will switch automatically.
7 j- O, N0 V [1 b0 Q5 R9 b ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
6 e8 q! o( A; F. u& ]8 P;; Setup Procedures ;;. n+ i5 E! u$ T0 f+ L
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9 g+ c6 o) y3 k. V; p;; Initialize the display by giving the global and patch variables initial values.
: n: V8 U/ M$ x;; Create num-cars of turtles if there are enough road patches for one turtle to
/ L# j$ i7 X8 N, ~" O;; be created per road patch. Set up the plots.
& l6 _4 t+ j$ g \% Qto setup8 Y7 m% M$ E @
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setup-globals
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4 M$ Y, z5 d& `! v( j! @, H ;; First we ask the patches to draw themselves and set up a few variables9 T/ v6 i G6 B! |. Q! C$ j
setup-patches' ?8 j+ K( f/ D$ m$ Y. t, }" q2 ]
make-current one-of intersections
" Y/ ]' T' ?# k3 F. L5 D. @# i label-current
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: |$ m, q) x+ }4 l1 M5 T: M set-default-shape turtles "car"
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% x3 t* C+ ?# X$ s. \5 f if (num-cars > count roads)2 \+ {8 A; W. \" ^: H* h5 M
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user-message (word "There are too many cars for the amount of "
2 Z$ f8 Y% h; o/ A) W$ f& e "road. Either increase the amount of roads "+ Y5 a' {) L4 X/ ]
"by increasing the GRID-SIZE-X or "# H7 k$ i0 u G- ]+ o7 [
"GRID-SIZE-Y sliders, or decrease the "& k+ X, g, Q' g& [. A
"number of cars by lowering the NUMBER slider.\n"
) F3 L" H3 V' G& U# V) K "The setup has stopped.")
0 p, k9 s' Z0 t stop6 {9 X, X7 |" l9 b7 r
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color: J4 R7 g* d$ m) S# D
crt num-cars. ]* i G+ o4 Y0 A5 S! b2 W- T
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. X" P, \! [4 s: E" g setup-cars
0 q4 h8 ~! N* J2 i6 \; s9 x9 w8 x+ A set-car-color3 J/ G# V3 m5 T i0 m
record-data O) w2 t% U" \" d) t+ D+ j' s, y8 K6 N
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0 z' q' r4 |/ `, \( a ;; give the turtles an initial speed0 ?) q7 l$ E: \
ask turtles [ set-car-speed ]
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reset-ticks
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g% k& D/ @, j0 C0 H* k" I;; Initialize the global variables to appropriate values$ d7 [5 {5 y3 }" b/ w4 e
to setup-globals
7 {5 N4 ]4 Z& N' J set current-light nobody ;; just for now, since there are no lights yet
3 ~8 b3 ]' M( w8 H# {& [ set phase 05 d% z1 x; K3 f
set num-cars-stopped 04 V: i O+ ~2 m3 Z v3 u, p
set grid-x-inc world-width / grid-size-x3 N, n9 n! D- p2 n
set grid-y-inc world-height / grid-size-y+ b5 b2 f( c9 m
. Y9 I# h! Y8 u1 |3 u ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
* h5 [1 d$ f2 u5 F3 x0 ^% x: X, I7 t set acceleration 0.0998 U+ ?; W* E- T
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,% \. L5 G. a9 ?1 G
;; and initialize the traffic lights to one setting% a. m" c, A( P) F: g
to setup-patches
2 e5 u9 l# s! V, y' _ ;; initialize the patch-owned variables and color the patches to a base-color
! t& u1 ` b( E" n& M& y' } ask patches
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set intersection? false+ X7 v0 x- J3 |* e4 E
set auto? false: _, D* }7 _3 W7 k
set green-light-up? true+ t* e: i/ {, M
set my-row -1
- W2 M3 P0 A9 M n% o2 d# }' I* K set my-column -1
% i+ Z% i! `6 w set my-phase -1
/ c P% x0 o% A# g$ j3 j set pcolor brown + 3" `/ D. n% k7 A
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3 u2 l8 j+ w& s% f" g+ A ;; initialize the global variables that hold patch agentsets
: r% u1 b" P0 g set roads patches with) Z* O2 m& _% Q' z9 t: K$ K- v
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or, h- y5 D2 g. {
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 `: @* x0 f+ w# N
set intersections roads with
: U. q2 U# z9 a8 m [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and3 @* L4 I2 l) @6 S" l. T+ r" b
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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E- t* e9 `- w ask roads [ set pcolor white ]# Q# M5 P( f6 j/ \5 e, M5 r
setup-intersections
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% R8 Y: k. {( {1 _+ j其中定义道路的句子,如下所示,是什么意思啊?
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/ D# e# R e9 J+ A t5 E [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" Q- m2 y1 q$ v
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: A! w7 j0 A7 u" x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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