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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。2 f) x" Q3 k! D
netlogo自带的social science--traffic grid这一例子当中,) M* \" K( M" D# ]: \) g% k) o" A
globals+ b& e- J! e' f& Q" i9 B0 }+ ^
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x7 y; N) t& a# \ grid-x-inc ;; the amount of patches in between two roads in the x direction
0 ]+ h) j2 j" I' E! T) L6 k c6 ` grid-y-inc ;; the amount of patches in between two roads in the y direction
% m, K: j# S. B. q( i acceleration ;; the constant that controls how much a car speeds up or slows down by if
" M3 S9 k! O" V ? ;; it is to accelerate or decelerate$ W8 E% G1 U# A9 k5 l5 ^% i7 \; n
phase ;; keeps track of the phase
, f; T. X* ?: T num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure0 l' b, Z0 t, ~/ U- T! s) a
current-light ;; the currently selected light
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;; patch agentsets
6 \# O9 x( ^2 R" l intersections ;; agentset containing the patches that are intersections
8 s8 ~+ p+ s1 ^9 i) A% X0 g roads ;; agentset containing the patches that are roads
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' H" X+ z9 z! s( L0 L2 sturtles-own
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speed ;; the speed of the turtle
m$ X$ j! p/ B2 p, C/ E up-car? ;; true if the turtle moves downwards and false if it moves to the right
; K' t8 i I4 i: o( W6 I2 i8 c% V wait-time ;; the amount of time since the last time a turtle has moved+ \0 [. L! j! B M% e
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& P) t; F1 _0 q5 H8 kpatches-own
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5 U ~3 R, E. ], E intersection? ;; true if the patch is at the intersection of two roads7 K' U. x$ E8 A* {% v
green-light-up? ;; true if the green light is above the intersection. otherwise, false.; T+ I3 a* ]) K/ G
;; false for a non-intersection patches.
; Y$ F! W1 Q5 {/ e1 J. l my-row ;; the row of the intersection counting from the upper left corner of the5 x$ u O0 r" @) @( n" X
;; world. -1 for non-intersection patches.
2 X! \# m- ~- D! Q# P r my-column ;; the column of the intersection counting from the upper left corner of the
% g. `6 X$ q- ~# Q+ d9 ^' _ ;; world. -1 for non-intersection patches.; Q0 w/ R6 p+ {
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
3 p( x4 e/ I% S5 B2 g+ x auto? ;; whether or not this intersection will switch automatically.
: m7 v, ^5 Y& @: |8 A ;; false for non-intersection patches.: \* s/ ]; z) E. o8 D/ M2 Y/ y4 |
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; W3 X. y6 ~) N' y9 I+ k* ?! A;;;;;;;;;;;;;;;;;;;;;;
8 _$ ^% p1 T* a7 T;; Setup Procedures ;;
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' C/ n0 J- h& _;; Initialize the display by giving the global and patch variables initial values.8 [ J) Q4 f6 k
;; Create num-cars of turtles if there are enough road patches for one turtle to, h+ J4 e, U6 z2 ^' T
;; be created per road patch. Set up the plots.* c, k: _( u1 s! q* B2 j
to setup" l( i( w3 A' e6 q! w
ca
7 d6 B. o4 F) j- J, U' L setup-globals
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& f3 H/ k- ~$ t' p' f$ P+ t ;; First we ask the patches to draw themselves and set up a few variables- B, O8 j9 q. t3 w K* N
setup-patches
2 U; n4 X& j" R( ^ make-current one-of intersections
5 \2 ]% f; I* x- h+ L- d; R9 S label-current
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; e( B' u. u, t9 O' I# F9 A L set-default-shape turtles "car"/ C9 Z0 d9 Q$ w# L7 ?4 q
7 S' g5 ?6 @0 |+ U! H if (num-cars > count roads)" M, D$ k' [/ U5 d9 ]! J
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user-message (word "There are too many cars for the amount of "
1 b+ ^2 w1 ~) L- ?$ y3 `7 z "road. Either increase the amount of roads " S# S; g* ~5 ^# S/ \* O; ?
"by increasing the GRID-SIZE-X or "1 U$ _2 i8 E+ e% ?2 k: J' R o
"GRID-SIZE-Y sliders, or decrease the "6 X8 z5 p1 _. d
"number of cars by lowering the NUMBER slider.\n"# p* V- |5 o7 |6 K- A* k4 [
"The setup has stopped.")$ g; F- g% G, [/ \/ X
stop O d* d: Z0 {# b
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& [* x/ A2 U7 o4 T0 W ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
5 B l9 d$ s3 \/ j crt num-cars
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setup-cars
( \" K& ?' q7 Q$ I1 G- y9 X set-car-color
+ p# \+ q/ x) P1 [) a+ _2 B1 q record-data
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3 E* ?$ F6 ]2 |5 M$ o) K7 n0 s# m ;; give the turtles an initial speed
, d$ B7 u3 C3 X3 z ask turtles [ set-car-speed ]! q, P; m/ N, v& |% q3 y! N
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reset-ticks1 K( D& l3 i6 f* V- {( ~; D- P
end
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8 ]6 L. ~9 p: K2 q;; Initialize the global variables to appropriate values6 q9 `9 ^0 Q% s2 @6 `
to setup-globals9 _" ^2 |" @2 ?6 ~
set current-light nobody ;; just for now, since there are no lights yet
[0 `/ z" u9 D1 f( E' j+ F+ X0 M set phase 0, J- ~' R0 L7 M
set num-cars-stopped 09 e+ T; C% X# r l( X) `
set grid-x-inc world-width / grid-size-x4 y% Y; p9 s. j; ~+ Z. D
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- z/ r! D% `' X
set acceleration 0.099
& ]; u; t8 m$ w2 mend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
5 ?4 v+ m& @8 L;; and initialize the traffic lights to one setting
+ [8 q' u8 q# J' X: S/ ?9 r7 dto setup-patches
# }1 e- N* I+ B) h9 { ;; initialize the patch-owned variables and color the patches to a base-color, S) w) U7 R& R' U! b
ask patches# x+ f1 {9 F7 K3 l4 r( u2 e
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set intersection? false
! y% R2 c9 O7 b set auto? false
5 z! z. _& j* ` set green-light-up? true3 U$ y5 n) z+ ]: E* c* e; o
set my-row -1" y6 L- a3 z& ]+ N! L) U/ u& _, v' M
set my-column -1) Y. ?4 P6 D6 b( r% \- O
set my-phase -1* Q$ J& t X$ g& U( M; _/ |
set pcolor brown + 31 H' a8 q# f" e( `
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9 j4 q. b( v6 A# _; G- O ;; initialize the global variables that hold patch agentsets% _; {5 x' k- N- |' L* l7 w. f
set roads patches with$ o6 e% Z* u C. n/ t$ y+ V- ]2 P
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or4 c2 X) |$ z: q! E9 Y# w$ i
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 q# ~% m* a D9 J M1 J4 ?( b
set intersections roads with
: h1 J, V% R9 {/ |, ~* H7 S [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and9 C/ R, r2 {+ R5 q' ?& k2 I( A
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]) D1 G# B' o5 z! s* E9 F
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ask roads [ set pcolor white ]; h0 x5 {" V& J& c4 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?
( r8 g& Q, k/ B& s3 [ set roads patches with
8 U: ^( j( F4 c3 G0 D; U: [ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 _6 O, _# G4 W& M (floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ ^& O0 _* ?: ?( n M
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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