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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。8 h# u8 q4 h" p9 O3 J3 R
netlogo自带的social science--traffic grid这一例子当中,1 h& c3 ?7 p5 G# G* d
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction e; l Z3 g$ [3 D$ }3 n; W, W t/ O
grid-y-inc ;; the amount of patches in between two roads in the y direction [9 W! X: ]. B+ P/ o
acceleration ;; the constant that controls how much a car speeds up or slows down by if
! E5 [* O2 S9 s1 l; x ;; it is to accelerate or decelerate3 R9 m. [3 L2 A) T& O
phase ;; keeps track of the phase- d9 @ e( \/ @* K. V
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure" E. w- k+ O6 ^/ T8 W
current-light ;; the currently selected light- F& O, V) m$ X6 V
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;; patch agentsets! q& z* ?, p1 v! g, g
intersections ;; agentset containing the patches that are intersections
/ _4 W O7 j+ k3 M) [; ] roads ;; agentset containing the patches that are roads0 Q1 E% }, w4 `1 Q" e: H( U8 C
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: a. A3 |5 B' P& Qturtles-own7 Z) T" ~3 x+ v6 t8 ~0 T. ?8 C
[
" t% q9 K4 n t- q: F speed ;; the speed of the turtle
3 E3 W, z g& m up-car? ;; true if the turtle moves downwards and false if it moves to the right
2 }0 B, j9 p9 ?8 e" E wait-time ;; the amount of time since the last time a turtle has moved
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3 _) V( t: A% A* opatches-own
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intersection? ;; true if the patch is at the intersection of two roads4 T) ^* n$ q% G. K
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
, _) Q8 i$ q- q! T ;; false for a non-intersection patches." z0 A* T7 I O
my-row ;; the row of the intersection counting from the upper left corner of the
/ l" {$ r+ U/ Q# [ ;; world. -1 for non-intersection patches.- `- y5 f0 x" A: G. E5 W
my-column ;; the column of the intersection counting from the upper left corner of the
# Q; [& T# j! W* N, U ;; world. -1 for non-intersection patches.$ Q5 Y5 ]$ @& i) B7 P
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
; F# ^! W: f1 K1 } auto? ;; whether or not this intersection will switch automatically.9 _ l% [0 }6 y" R4 T7 x( c5 ]
;; false for non-intersection patches.
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2 Y& s9 s. ?/ X; w) `& R% Q;;;;;;;;;;;;;;;;;;;;;;3 J" |; i* u+ G+ S/ C1 {3 D5 h
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.3 T7 q# o7 d0 }
;; Create num-cars of turtles if there are enough road patches for one turtle to# m; \% X d# k: u1 l8 O' F
;; be created per road patch. Set up the plots.1 P! ]2 }0 v2 S E1 ^$ L0 H
to setup7 C9 B6 U# e4 E: d7 c+ F
ca
- g D% }4 n4 B% Z setup-globals/ g; H. ]+ E) E0 S+ ]
, K- U( g# d/ p8 \$ Q/ d2 h9 H ;; First we ask the patches to draw themselves and set up a few variables
+ k6 g8 ~! r3 \ setup-patches# C9 b6 m# ^# ^; a7 `. Z8 `! k# o8 m
make-current one-of intersections: L2 h4 G$ z2 X; N/ ~- T
label-current0 o2 \; j d8 m/ [" F' ?
9 N0 A5 Y- v6 h' u set-default-shape turtles "car"
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of ") w/ E# h- b0 k b# }
"road. Either increase the amount of roads "
9 S& R" y1 ~( i% J4 W" m% \ "by increasing the GRID-SIZE-X or "
0 T3 g; G, a6 ? "GRID-SIZE-Y sliders, or decrease the "
% c1 s. F& ~; @+ o& A; ^2 U& }: p0 j "number of cars by lowering the NUMBER slider.\n"
, I. M* @8 T$ ?; P* Z2 A( D) d "The setup has stopped.")
* ~( ?$ ^/ \% M n" \4 M$ g stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color* U+ r4 D' Q8 s _ K' C! E$ h; a! i
crt num-cars
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setup-cars
7 }' G, f+ j" _; n/ y: B# V; H set-car-color7 Q: Q( a; `$ p' Q7 ~
record-data- A7 [! f. p* ]. ^/ T( a t6 N
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$ G4 l7 s7 N" g$ m ;; give the turtles an initial speed
8 O: F$ O3 J c' f8 E$ z7 T ask turtles [ set-car-speed ]
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0 F) y* ]% Q' W, u' ? reset-ticks
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;; Initialize the global variables to appropriate values7 m5 d) m |4 n
to setup-globals
- j3 Q$ q! V7 M! x% S }( ` set current-light nobody ;; just for now, since there are no lights yet/ R6 O8 k2 n1 {. o
set phase 0
0 Y" @& x0 H! Y5 B1 m set num-cars-stopped 0
) ~; z9 ]$ b2 Z: ~& Y* o9 \$ G set grid-x-inc world-width / grid-size-x
: ~" M( A7 m. ~ set grid-y-inc world-height / grid-size-y. H5 i8 r$ o/ t6 T2 J
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
: n& v# f! l- F: z set acceleration 0.099# y) |( M% h+ d
end
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. l, T1 A" I4 `* U- ^) `# a;; Make the patches have appropriate colors, set up the roads and intersections agentsets,, b5 v. ^- |% g: ^4 c9 m
;; and initialize the traffic lights to one setting
8 u1 p s( v, s. _to setup-patches
' L+ r7 } H4 O3 D' m" T# B% c8 q ;; initialize the patch-owned variables and color the patches to a base-color) e* N5 Z3 Z1 }; `$ A
ask patches
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; Q& z( z* {# e! } set intersection? false- L9 L$ y W' Z; H! u
set auto? false
% U5 {- H' E6 }5 b% h% s set green-light-up? true) K! x- Q, A; p# J& A! k1 {
set my-row -1
% ~0 u. q" x* t/ g+ X: M- v" }$ d S set my-column -1
Y/ {5 R4 ~0 a- R set my-phase -1; b+ B; w8 d p+ w7 z/ M- x, `
set pcolor brown + 31 Q( ?) w! {( I _5 r
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! N; ~( _5 h8 T: U. d% {' Y; s ;; initialize the global variables that hold patch agentsets) i/ ]+ d! d9 e N2 X8 A
set roads patches with
' Y( w0 T) C2 A [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 y2 k$ U0 N( x- S( a/ m (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
|. _! g" ~0 I2 f, P! ^ set intersections roads with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 o7 x. O7 [' P b9 H
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ask roads [ set pcolor white ]
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end& l+ s; g7 G. G# T0 I1 D7 U' b
其中定义道路的句子,如下所示,是什么意思啊?2 M& S: b8 x% {% _
set roads patches with+ x$ O7 R1 V( D, z! g; i
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% @) J( X) x i% d( P
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; }+ ]% s& g6 G* _7 C$ ?1 a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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