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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。- Q8 B/ S z9 f2 q& m
netlogo自带的social science--traffic grid这一例子当中,
j H& x) p- ~( u! B/ o! Iglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction: n" c0 a2 s/ `+ o6 e( m
grid-y-inc ;; the amount of patches in between two roads in the y direction
, y4 E4 ]/ g3 `! L/ R4 C acceleration ;; the constant that controls how much a car speeds up or slows down by if
( L, {( X4 J' p1 X" |) L. `) r' X$ K ;; it is to accelerate or decelerate
3 x/ ~( Q9 @' b* a; h/ F, i phase ;; keeps track of the phase2 t6 H5 f8 G9 M( ?( s) `
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
# Y3 V, [7 x/ e' y+ U5 o current-light ;; the currently selected light9 c, r( p9 a l6 g' m
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;; patch agentsets: g; x: `9 t; Y8 \: \
intersections ;; agentset containing the patches that are intersections
8 E5 }/ Q3 \* `6 U* O6 h roads ;; agentset containing the patches that are roads
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2 E$ u4 n. g2 c7 `' Pturtles-own
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( A& e- H3 C& U; j/ K. h$ J9 O speed ;; the speed of the turtle
6 F& ^, {/ B7 U up-car? ;; true if the turtle moves downwards and false if it moves to the right4 W5 r% h% `6 J7 b( w+ A
wait-time ;; the amount of time since the last time a turtle has moved
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& n* ]3 i. Y& @& Dpatches-own, ^$ w) B, z. f D9 n! N: L5 ?( p
[
5 r' f0 f$ d9 W5 ^ intersection? ;; true if the patch is at the intersection of two roads
: l) f2 w% P. n7 f: q green-light-up? ;; true if the green light is above the intersection. otherwise, false.
9 [; }; K8 C0 P- f1 s ;; false for a non-intersection patches.4 k0 k# l/ n6 I; c
my-row ;; the row of the intersection counting from the upper left corner of the. R; A) M/ W% {
;; world. -1 for non-intersection patches.8 `6 X3 N3 n. T- H$ J( n# O3 G" j
my-column ;; the column of the intersection counting from the upper left corner of the- r I% F+ d0 u
;; world. -1 for non-intersection patches.
5 L( [' q$ ^& n' { my-phase ;; the phase for the intersection. -1 for non-intersection patches.2 @( m5 A. U) o$ |( T7 [4 n7 c
auto? ;; whether or not this intersection will switch automatically./ r2 a4 p( f) [& p1 E9 _3 W
;; false for non-intersection patches.
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: k% j0 M: Y1 s& C' X+ c% J;;;;;;;;;;;;;;;;;;;;;;( w7 b0 x' R% v& r& W* x
;; Setup Procedures ;;9 `* z( B- c+ h& a) ] D/ N
;;;;;;;;;;;;;;;;;;;;;;! Z2 G( x+ r# D2 Y/ W/ F ]
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;; Initialize the display by giving the global and patch variables initial values.
) ^5 z f5 p1 a; M;; Create num-cars of turtles if there are enough road patches for one turtle to3 Z) I/ l( ]$ I6 ?+ r# i' a
;; be created per road patch. Set up the plots.' C9 r2 m* g3 S
to setup
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables+ l+ L3 {- Z! @2 |# M
setup-patches
4 j. R. d8 L& }" v, e2 B make-current one-of intersections
0 @; }2 m& G0 L9 X+ ~ label-current
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set-default-shape turtles "car"+ F) o. x% ?8 L, e
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if (num-cars > count roads)) v$ p, x$ C/ m7 L( `4 K
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user-message (word "There are too many cars for the amount of "
; J+ T9 s% Z) d8 T "road. Either increase the amount of roads "" ^3 j7 Q7 x% o
"by increasing the GRID-SIZE-X or "
0 X! e! R; s. p "GRID-SIZE-Y sliders, or decrease the "
1 J$ ^6 C' |+ [' K% U3 A "number of cars by lowering the NUMBER slider.\n"5 I6 y7 Y) M' E1 o5 a( W2 B
"The setup has stopped.")/ p7 f' q- { O: A1 x6 p' i
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color1 M8 J% P7 ]! Z/ u
crt num-cars
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setup-cars
. f- y, g3 b, b0 \: m set-car-color! ]0 A* `1 t7 X; T4 z( D$ ^9 a
record-data
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1 ]' u, z- b$ {+ X9 n& h* z ;; give the turtles an initial speed/ U; B+ g6 F: T0 t
ask turtles [ set-car-speed ]
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reset-ticks
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;; Initialize the global variables to appropriate values
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4 b" R: A, s3 I set current-light nobody ;; just for now, since there are no lights yet
1 w5 O/ P2 ^* E t' v* F set phase 0
, ~* [* a" E n; v set num-cars-stopped 0
3 b" N6 F9 y k! C set grid-x-inc world-width / grid-size-x
0 [/ Z! n+ w( b% a" t) j9 S 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
" g7 t2 l1 K1 ]! w$ ]# R9 m set acceleration 0.099
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3 p$ V$ E r5 D;; Make the patches have appropriate colors, set up the roads and intersections agentsets,1 d& @" r/ D7 F: l8 @
;; and initialize the traffic lights to one setting# C3 L; J" i! N5 h. }- q
to setup-patches
; c) C4 v- r1 B* O6 X% P1 A% t5 t ;; initialize the patch-owned variables and color the patches to a base-color. b" r R N; m$ P. H2 q7 n4 p" j
ask patches
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4 i& t- \+ p) V5 x1 z& p set intersection? false5 r. a: a3 c6 Q; }* V: |
set auto? false
& w6 t- @3 d3 o: y( @ V2 E7 O set green-light-up? true
4 P3 @% L8 H' `* K set my-row -12 L, V( c4 P* H8 H( Q6 j- c o$ h }
set my-column -1
5 G0 W! u2 b8 f$ ?, U set my-phase -1
7 Z q( C: l w' g( n9 r set pcolor brown + 3+ |% C7 @9 R0 P$ W# s1 o4 x
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;; initialize the global variables that hold patch agentsets
# b! u) H. l0 j$ v& {8 H6 D set roads patches with
6 ?% q: V/ K( R( H [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or8 T9 O- _9 {5 @) g. q! i
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 |. S' t' K/ p8 _0 _
set intersections roads with
' ]4 s! L9 N- }. }2 m [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and W2 V0 A, ^9 v
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]# H& K% a' L4 t5 [
% }' }& M7 h; z# h# c ask roads [ set pcolor white ]8 Y+ I) V) n2 R' o2 U' N ^
setup-intersections
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/ {$ q+ D0 J8 E; B其中定义道路的句子,如下所示,是什么意思啊?
$ Q" f/ ]- s' f set roads patches with
0 H" J. T$ K7 b) I [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
; O2 A, N% r1 Y. v, D (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
+ h7 [- Z+ h r; u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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