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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 m: g0 s+ m8 \3 {" Jnetlogo自带的social science--traffic grid这一例子当中,
+ h3 Q6 b5 b7 j! zglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction( x$ e3 i( m1 M1 s' |
grid-y-inc ;; the amount of patches in between two roads in the y direction9 Z/ G) Q# m7 c) |/ ^5 C
acceleration ;; the constant that controls how much a car speeds up or slows down by if) l% r. C3 D x3 W- }# N' x
;; it is to accelerate or decelerate# c; _4 W- C& {/ J( u0 ~
phase ;; keeps track of the phase1 K: ^& V3 G U! g0 G u
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure+ J* }! U& a1 {0 P0 d
current-light ;; the currently selected light" G9 J& ^- n% N* o2 h
9 s, E- ~2 h d# ~, j8 @ ;; patch agentsets2 w( A$ G& ^( w1 d/ z
intersections ;; agentset containing the patches that are intersections( q7 f0 |1 e S: A' G% b& [) [
roads ;; agentset containing the patches that are roads. X- g$ j3 F/ q
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- A3 f2 i. H5 a. t+ }2 e5 gturtles-own
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$ z, a" M. Y1 w* |* o6 S8 u speed ;; the speed of the turtle
( L7 ?9 o5 u7 E; d5 Y3 t up-car? ;; true if the turtle moves downwards and false if it moves to the right; u7 ^4 C' q2 \/ _7 Q0 k. N
wait-time ;; the amount of time since the last time a turtle has moved0 H5 w! [: b& L: L4 n7 X
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patches-own3 Y" b: Z) W4 I3 R" y' f! {' [
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intersection? ;; true if the patch is at the intersection of two roads
+ L! U, i7 k S green-light-up? ;; true if the green light is above the intersection. otherwise, false.
/ J9 ~8 b) v% o ;; false for a non-intersection patches.& y6 [* s3 d6 }& v
my-row ;; the row of the intersection counting from the upper left corner of the
5 N: l I( T7 K$ j" } ;; world. -1 for non-intersection patches. C. \, V3 a( l9 r) f
my-column ;; the column of the intersection counting from the upper left corner of the
$ C5 k' A1 Q7 k/ x/ ? ;; world. -1 for non-intersection patches.2 u6 I+ D* F& ~/ k5 ?6 A0 }
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
0 @0 @9 q, L$ [8 a* \" W auto? ;; whether or not this intersection will switch automatically.
' U6 J; L/ p8 z7 w+ n$ Q* g ;; false for non-intersection patches.
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3 w+ q+ Y/ \/ @0 o;;;;;;;;;;;;;;;;;;;;;;! L- x1 X( j; q3 s/ w0 S" F4 C
;; Setup Procedures ;;( a7 R0 t/ U! Q
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
3 Z( l3 `/ s- S. f, S;; Create num-cars of turtles if there are enough road patches for one turtle to
1 s; |) R. ?3 C4 G;; be created per road patch. Set up the plots.
4 N2 Q/ M& C5 l0 Z* p% h( H$ pto setup
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;; First we ask the patches to draw themselves and set up a few variables
3 {0 e& y W1 z. ]3 z- K setup-patches1 ]0 p! H9 U# \1 C# R% H. L
make-current one-of intersections" C& ], w2 M3 ?$ W
label-current
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set-default-shape turtles "car"0 \# P& P' N. t' u% t
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if (num-cars > count roads)9 g7 e/ n" Z# V
[
9 l/ |7 [7 }; F" p# r/ A1 p! v b }! L user-message (word "There are too many cars for the amount of "& q$ N6 r) O, x, t1 Z! w: y* v
"road. Either increase the amount of roads "7 Y# k, k* B2 @
"by increasing the GRID-SIZE-X or "
+ L U/ i$ w2 C/ T8 B "GRID-SIZE-Y sliders, or decrease the "
1 i0 o% c* `( @! b2 Y0 Y6 {% V" f1 S) G "number of cars by lowering the NUMBER slider.\n"
* H9 b( N% O0 m/ S' g4 `! R "The setup has stopped.")
6 F0 C$ g7 s( G, S* g stop+ X9 |- L4 K7 Z! }- v+ q3 L9 n
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6 b( L: z+ r) s, \5 Z L0 p* F ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
2 ^* k0 b* O) o' H1 ] crt num-cars& L% A2 e- |5 M+ M
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setup-cars
( o6 c C+ R# \- L. o4 \ set-car-color
( {) k B0 i9 r2 r' c# V record-data
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6 x1 K. X9 u+ s- n2 k ;; give the turtles an initial speed
9 ^5 M9 C% d5 |, d ask turtles [ set-car-speed ]/ u. _, ]* }8 |8 z, J
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reset-ticks3 Q# j) M' d- F8 f8 u0 m
end' p+ o6 X- k. c' n$ g( j0 I
4 f) ~- @4 W! X B5 `;; Initialize the global variables to appropriate values- ?- C5 m Q5 H" S3 C
to setup-globals: C1 ^0 Q# w7 G/ h( J
set current-light nobody ;; just for now, since there are no lights yet) x4 ~: S$ J/ W7 T( X: X
set phase 01 ]7 W1 b: F* m! o( b5 ]& d0 C% v
set num-cars-stopped 0
, ]; l3 T( h! N set grid-x-inc world-width / grid-size-x
! `; J- w5 [- b* |, q) q- @ set grid-y-inc world-height / grid-size-y
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' {* T% r$ G- Q- E: z9 i ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
+ \; L9 h: q! M e& c- N0 a9 [- d set acceleration 0.0991 b' _& q% R( p0 @4 J" u; {
end
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% }/ |$ c N3 j8 N;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
( ]9 ~# G8 [! _2 Q5 C$ u" j;; and initialize the traffic lights to one setting
% h; S' T1 A- jto setup-patches
- b5 x" M r6 |) [4 f% M ;; initialize the patch-owned variables and color the patches to a base-color
% j% P/ D. O- S8 I ask patches' t; L2 o; m8 o$ w
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set intersection? false
, i, z* n, N) |+ p! i& A set auto? false$ ^9 f% f% I4 t: o$ f; T
set green-light-up? true) y2 O: J( K# | Z$ R+ r
set my-row -1
\7 P; @- I& ~% x. _ set my-column -1
- ]% d* S* u* ^2 ^9 M- y: s set my-phase -1
5 y4 W$ f& i" Z4 {& T/ k% m# T set pcolor brown + 31 y9 {5 b$ ?& K( g' s$ u& ?9 x
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% {( `1 Z# h+ v' R7 t9 j ;; initialize the global variables that hold patch agentsets7 P& J4 J0 ~# H, i( l4 ? `3 h
set roads patches with- h- v* p& [9 e
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: V6 S! A3 m, d4 @8 r i( t2 ` (floor((pycor + max-pycor) mod grid-y-inc) = 0)]( J* {% m7 t( O6 X; W' d
set intersections roads with! J1 v! Q4 Z6 C4 _
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
3 e- y8 {* n( O/ i1 g! K8 n- M' j (floor((pycor + max-pycor) mod grid-y-inc) = 0)]: `2 a. F; H( g& h) \6 L5 D+ Z
" w# ~* d! Z) ?7 a' H5 Q$ A ask roads [ set pcolor white ]
& g+ ?* b: K' l( ?" i, c; W setup-intersections
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8 W# l' e0 Y: D. W其中定义道路的句子,如下所示,是什么意思啊?, \; H6 [& W% R$ a
set roads patches with* J A, s# H! s# [, l
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 d, `* x- z2 m9 r6 C# N- Y' G (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; ?# d$ U$ e. F$ ^) ^) Q8 I8 f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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