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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 C- J2 y# E+ e- {
netlogo自带的social science--traffic grid这一例子当中,
|: M+ \: [- Pglobals
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0 v" l2 I& r0 S$ R! ?& d grid-x-inc ;; the amount of patches in between two roads in the x direction
3 i- Q( g) J# Y, t2 e8 B grid-y-inc ;; the amount of patches in between two roads in the y direction
/ l. g2 ^( r0 p+ ~( |: @ A2 } acceleration ;; the constant that controls how much a car speeds up or slows down by if
9 Q9 ~0 Q7 d) q, M* H3 b0 c2 g+ w9 M ;; it is to accelerate or decelerate
+ |0 ~* y* }6 q2 \ phase ;; keeps track of the phase y! `0 H$ H, c/ \
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure; q7 ^8 h8 ~* a; w
current-light ;; the currently selected light, H* R; f- c' Q: }+ C
% _1 c# x6 ]; ]- G. P& ~ Y% n ;; patch agentsets& f, U4 u3 o3 U! X3 }
intersections ;; agentset containing the patches that are intersections
' l* M& P+ R; _ roads ;; agentset containing the patches that are roads+ o: L' S ~. E4 V3 D0 _( M2 l' C
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* i0 N! b. t1 \ I' tturtles-own0 |9 F# h1 e1 d( V9 M. k
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+ ^$ T) [" E) v% U: } speed ;; the speed of the turtle5 u; O7 o, b/ f. `" u
up-car? ;; true if the turtle moves downwards and false if it moves to the right- ]4 O. O/ v O+ C) q$ @. c
wait-time ;; the amount of time since the last time a turtle has moved
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' Z# c5 t2 v+ b6 D- q" ]patches-own) i7 G+ T" J: n/ A
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intersection? ;; true if the patch is at the intersection of two roads
# t! U% e, e" B! ^8 v& V green-light-up? ;; true if the green light is above the intersection. otherwise, false.
: Y4 U4 N) _0 ?) z# V: h ;; false for a non-intersection patches.8 f; m8 R4 d) E7 ^
my-row ;; the row of the intersection counting from the upper left corner of the- B+ C N4 i4 }" O' @- s4 L
;; world. -1 for non-intersection patches.8 k! M" D1 A8 H% P ]: h$ m
my-column ;; the column of the intersection counting from the upper left corner of the" z5 W5 G, K6 S# F4 n
;; world. -1 for non-intersection patches.! M/ E9 {8 J+ t4 D; U! h5 y" F) l& g, w: U
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
* _- T4 E* c+ L" l- l; @ auto? ;; whether or not this intersection will switch automatically.
$ C- k. l$ _5 b% v& V3 D, }8 M0 \ ;; false for non-intersection patches.
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8 z. T; S! ]) `;;;;;;;;;;;;;;;;;;;;;;3 M ` m6 u {. p' w
;; Setup Procedures ;;
- a+ G7 |9 m" S u;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.* \4 } G# g1 ?7 W* h9 i
;; Create num-cars of turtles if there are enough road patches for one turtle to
! ^1 m, V5 u' D+ } s$ _;; be created per road patch. Set up the plots.
- z0 L+ k" K5 |8 r$ p ito setup- Z" L0 r% b2 M7 ^8 G
ca
$ X- C# f6 ]7 I/ c( r setup-globals
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;; First we ask the patches to draw themselves and set up a few variables4 g3 G/ d+ I5 D; m& Q
setup-patches
) ~& o( c! \# {% s0 t* n make-current one-of intersections
; {8 f) K& C) [& b7 i3 ^ label-current
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4 J& j8 c2 ?; v- i/ @ set-default-shape turtles "car"; q" k$ p7 C2 Y f: L5 O
0 a2 h. p; g! b$ ^0 C, o$ G6 I if (num-cars > count roads)+ p& M7 q4 g! F% A+ F
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user-message (word "There are too many cars for the amount of ", w2 a0 z8 i( ~ B3 c
"road. Either increase the amount of roads ", a3 p) _& J6 a; d* x
"by increasing the GRID-SIZE-X or "2 w7 }4 c* }7 i4 Z( K6 D
"GRID-SIZE-Y sliders, or decrease the "
5 C! w$ J" F. G `1 v9 E. s "number of cars by lowering the NUMBER slider.\n"
7 L+ \* H: o0 i8 _+ `& K/ X "The setup has stopped.")
% ?5 G8 ~, p9 ]5 Q) N stop7 c. r- \7 n! ^# d" p/ c' e e
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
; f6 U5 Y7 m# x, M crt num-cars$ @5 z, M2 E' Z+ d. \: r
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1 ?2 X: I0 z$ K& D) G setup-cars! g, ~. B0 k0 g* U+ V
set-car-color/ T' x/ J& H9 M# P
record-data
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+ J) `4 u" Z3 S ;; give the turtles an initial speed
* c, D# l: ?6 m/ J! z* b+ d ask turtles [ set-car-speed ]1 h) i6 E+ D9 s0 @5 `, f6 @8 F
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reset-ticks
, y9 ^ ?) N" h7 |end# w' i- i7 k( ~! _! D
& r1 Q; R( S9 _) i;; Initialize the global variables to appropriate values4 j2 u% g2 _+ ~" D* ]- J
to setup-globals. L" N) i8 T# ^2 f: K; b
set current-light nobody ;; just for now, since there are no lights yet. ^6 p& S9 Z$ m0 q4 [+ X
set phase 0; s- e, y! x. P8 o7 l
set num-cars-stopped 0
I+ c) f' z) ?* p set grid-x-inc world-width / grid-size-x2 p' C" v6 t A9 ~
set grid-y-inc world-height / grid-size-y( W' I6 W% d( o+ {
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
9 ?! L& _1 t! O& S; h r% ? set acceleration 0.099
2 a& I9 c+ N4 `$ J* t% kend
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9 E' }# W! \5 M( q/ ^# _! c; ]. c;; Make the patches have appropriate colors, set up the roads and intersections agentsets,7 \/ s& \/ a# t- j1 _+ S+ B
;; and initialize the traffic lights to one setting
# ~& _1 Z7 n! H: [$ i9 @2 u9 M q$ Lto setup-patches
$ e( N9 x; w( |% ~6 |0 J ;; initialize the patch-owned variables and color the patches to a base-color
7 P; r( D! \' l" t, {3 [ ask patches# M1 B. r- M+ ~1 ~) |. D% y/ o
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$ Y/ k9 `- K3 Y2 B set intersection? false+ d$ K0 z5 Y7 c( M: h2 \' I
set auto? false- g. b4 O3 ~2 d" t( T- R0 f
set green-light-up? true4 i2 R; b) S9 N' ]3 w) \
set my-row -1
7 L3 ^' E C0 q# { set my-column -1- _9 t+ O4 q6 f, m# u" B
set my-phase -1 f% u, n6 U$ ~
set pcolor brown + 3
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; \( `. L. v( @ c+ ]* i ;; initialize the global variables that hold patch agentsets6 B( s0 M/ R+ q( w0 M
set roads patches with
: N" M+ p9 T% Y6 S [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or* K4 M3 W t- |6 r7 p
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 m+ R) ]9 U7 g! H* q0 L+ ?
set intersections roads with
& ]2 f* F- R% Z [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and% X" b) O. g' W
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]* }0 K0 D# R8 W
setup-intersections: c L$ ^4 o4 e# f3 t3 K
end( N, y9 ]- y J0 S
其中定义道路的句子,如下所示,是什么意思啊?
# r1 a5 R% d2 Q/ w/ B set roads patches with3 ^1 ~5 T& R1 l0 s1 c
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
* G6 {! S4 l6 y8 X0 b0 D7 h (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
" [2 ^& F" h7 c7 G% {3 H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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