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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。4 W* \, ^' Q# u, y# {# B
netlogo自带的social science--traffic grid这一例子当中,3 f4 B4 T/ G+ ~: v+ n% B
globals
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/ v9 |! F9 A* e* y3 m# o, B" Q grid-x-inc ;; the amount of patches in between two roads in the x direction% y# W; {. e5 E& M
grid-y-inc ;; the amount of patches in between two roads in the y direction: Q0 X4 Y, P6 o3 x. o5 T7 I
acceleration ;; the constant that controls how much a car speeds up or slows down by if; s1 P1 k B) R1 I0 v3 }; p
;; it is to accelerate or decelerate
. P) B4 `1 q7 L1 a5 a- ^7 X phase ;; keeps track of the phase
9 T% ?4 B8 O% I num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure: g1 p3 k( u* }4 h F& q
current-light ;; the currently selected light* j1 p( Q" k0 Z+ s: ~" ^
8 c) s8 L0 F6 |$ u ;; patch agentsets
- y* Y7 q4 k# f intersections ;; agentset containing the patches that are intersections
$ b5 i1 x! K; R) [. Q roads ;; agentset containing the patches that are roads$ r- f* X- A8 d0 F/ a# C5 q
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1 Y2 E9 ? v( p/ @! iturtles-own# O- J! Q2 E+ H& b" D, b) Y) \
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speed ;; the speed of the turtle& u1 b* y$ O) {& r l$ o9 C9 r
up-car? ;; true if the turtle moves downwards and false if it moves to the right
* V5 V l2 A4 i5 O wait-time ;; the amount of time since the last time a turtle has moved
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. v; s7 D4 s! i o+ zpatches-own/ S' E' F0 N; M0 P7 o+ E
[
3 d7 u0 d5 m5 n& S5 P intersection? ;; true if the patch is at the intersection of two roads
9 ]1 x0 G4 b' @$ c1 c) n green-light-up? ;; true if the green light is above the intersection. otherwise, false.7 h: P: `$ q" X( K. y, t ^
;; false for a non-intersection patches.
! `6 T) U- b* t- c2 D my-row ;; the row of the intersection counting from the upper left corner of the6 l- ]1 }: p2 l7 s! N" c
;; world. -1 for non-intersection patches.! K* p; m( T9 C; U* x9 p
my-column ;; the column of the intersection counting from the upper left corner of the
- q" n5 H6 w4 P. K ;; world. -1 for non-intersection patches.
" s4 ?/ _- O1 b, O: y$ }1 \+ K0 U my-phase ;; the phase for the intersection. -1 for non-intersection patches. X5 ?! B+ [3 j) G0 t4 E
auto? ;; whether or not this intersection will switch automatically., t' g3 T8 e5 I. ^7 w8 l% }
;; false for non-intersection patches.% ~4 D6 b% P2 w0 ]# {* q7 J9 J& q
]
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;;;;;;;;;;;;;;;;;;;;;;; t3 h! ]* n3 `; c- D& v
;; Setup Procedures ;;% {3 d" H4 E( h! C" n
;;;;;;;;;;;;;;;;;;;;;;
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5 ?7 x5 G4 p+ e* O;; Initialize the display by giving the global and patch variables initial values.
( A* l) O2 x2 c;; Create num-cars of turtles if there are enough road patches for one turtle to( o8 ?' U: \2 `6 h: c8 x6 \
;; be created per road patch. Set up the plots.
7 H0 I' o4 ~7 a3 r1 Ito setup! _0 W- y$ [: _& C; ~" d W7 D% X6 }
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setup-globals0 c9 @, e# E* Z
A% a! T4 R8 G& C0 V ;; First we ask the patches to draw themselves and set up a few variables1 [$ g+ O8 U, u, w7 Z8 p( {
setup-patches
, j9 _7 t a5 e( I$ e# p make-current one-of intersections
- ?. @% H9 D% C9 y9 v: P9 \ label-current8 x& `* X" K" b9 E- ~' l# [
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set-default-shape turtles "car"
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: I& J ?+ j+ r if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
9 s9 @/ |" D; \; ~5 T "road. Either increase the amount of roads "; H8 m4 l. ~7 K6 z0 t
"by increasing the GRID-SIZE-X or "9 u0 D, u4 S' s `7 b
"GRID-SIZE-Y sliders, or decrease the "
8 b4 p# m7 i; g0 F- z "number of cars by lowering the NUMBER slider.\n"
) p3 t( P9 o+ F2 c0 b "The setup has stopped."): [# t5 }, K8 ]4 t
stop/ F# ^5 q2 g8 ]9 o) E
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
R4 f; j+ S t crt num-cars
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. g( I& z- V( I- @/ a setup-cars
) u5 T4 b2 X; A0 s) ]% k( V% O6 v set-car-color0 _# o9 k6 p$ y0 [6 _
record-data6 d" b' g6 y! ?( [2 t* J$ a
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' I4 Z, B4 t+ n( C$ I" G& C ;; give the turtles an initial speed7 U, n: P* }' f! b# K0 P6 g* v7 _
ask turtles [ set-car-speed ]
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reset-ticks6 P* {- V0 l$ C2 N0 z: j
end* l9 @+ U$ N0 s) z V" n5 r. Q9 X
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;; Initialize the global variables to appropriate values) k( z: |% J" F; V4 N- n2 U
to setup-globals: W! I7 @ O F) _
set current-light nobody ;; just for now, since there are no lights yet
7 J) \! e( x5 K1 j3 R* N K set phase 0
4 Z- `& R8 R; C0 m# s$ W& K' E set num-cars-stopped 0
1 `2 s! p7 B6 N. W- P1 A set grid-x-inc world-width / grid-size-x
: F* l+ l/ j1 e1 k1 Z 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# R. I5 k1 z3 h P: w& ~
set acceleration 0.099
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6 }0 Q5 Q8 N2 b1 @;; Make the patches have appropriate colors, set up the roads and intersections agentsets,3 j/ \8 P3 i* Y, J5 x% L
;; and initialize the traffic lights to one setting' ^7 K5 c9 J7 g9 F5 K2 _0 A& G# e
to setup-patches
3 w% ]! T! x- m# u8 R ;; initialize the patch-owned variables and color the patches to a base-color
6 ?; a% O# u3 W( ?) V ask patches9 J6 k$ s- ?2 J/ `1 n+ J
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! O5 V o0 z; j, Y Y; Q set intersection? false
+ I/ u5 Y9 u8 T; @0 J& k# o set auto? false
0 y, J5 z/ S- Z6 d set green-light-up? true0 k; K5 ?; _# Z
set my-row -1
; d: ~9 E9 o" g+ b set my-column -1
8 O7 S7 Z( L" Z; A- W set my-phase -16 j/ g& O& z8 x+ A# ]
set pcolor brown + 3+ i$ M( E* L( }9 o: [8 T
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4 S- E: C; ~! Y5 b ;; initialize the global variables that hold patch agentsets7 \: K' J0 j; p5 m0 H
set roads patches with- C% ^. z. j9 b
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
% g8 K8 S1 s2 _4 f (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 ~4 _8 b0 h5 U. r set intersections roads with- Y$ r: J7 _! z$ W- n; N
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and$ }( @3 S+ j$ [. @$ a9 C1 l8 L
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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. A# D' y$ R% [7 [ ask roads [ set pcolor white ]
4 p! D8 v, l$ L+ | 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?
0 Q2 |5 f8 B6 U! H( r set roads patches with; v) s) }- d# e
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
0 h' o! w" W6 g; k (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 O: P2 } G8 T ?, W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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