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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。
( H' P) f' z: d0 Snetlogo自带的social science--traffic grid这一例子当中,
6 U& k. }; n, k: S0 Q! Kglobals) f- G% e2 h) k' [, }3 f9 v
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grid-x-inc ;; the amount of patches in between two roads in the x direction
+ C8 l9 w o- U }' s0 ] grid-y-inc ;; the amount of patches in between two roads in the y direction
7 q- w( C& n6 J9 \* X# u& @ acceleration ;; the constant that controls how much a car speeds up or slows down by if% P2 Q/ ^/ n2 u& k5 [
;; it is to accelerate or decelerate5 Y6 s8 O, W9 r3 W4 A2 ~
phase ;; keeps track of the phase. ^! h5 v% G& O! ^$ o7 E
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
$ @% w% B# l0 _) m current-light ;; the currently selected light, J5 C1 v( [: J* z& R) R& e& j X# w
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;; patch agentsets& w. @$ e7 T8 e
intersections ;; agentset containing the patches that are intersections8 }% q. e1 e/ B! P2 J4 v
roads ;; agentset containing the patches that are roads0 K+ Q/ \; B) x8 w3 d+ x
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turtles-own$ O# v" W, e4 J
[
- O+ s# U6 P: }; u) H# i speed ;; the speed of the turtle
& A# w% W: e) V5 z up-car? ;; true if the turtle moves downwards and false if it moves to the right7 {3 B* Y6 ?$ O1 P: i4 M
wait-time ;; the amount of time since the last time a turtle has moved I/ A o8 p+ G4 ?
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9 d" d. a; v9 c: T- Zpatches-own
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4 d. U2 N; J! M/ o/ t8 J intersection? ;; true if the patch is at the intersection of two roads- Y8 p9 K2 c, c' R, }
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
8 \" ~5 d' c) s$ H ;; false for a non-intersection patches.
5 e7 \$ W9 ?; p2 V2 g; L my-row ;; the row of the intersection counting from the upper left corner of the
" @# n9 i3 M% B( X ;; world. -1 for non-intersection patches.
, ?; A7 |+ z D. r( u( ~ my-column ;; the column of the intersection counting from the upper left corner of the' j" j3 w0 u6 r! H
;; world. -1 for non-intersection patches." v# J5 K, P+ |9 i/ ]( b3 w
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
5 G4 N- M. I" d0 G1 G6 @+ U auto? ;; whether or not this intersection will switch automatically.
7 v% t) I; G! h# i0 |$ ^9 n2 o ;; false for non-intersection patches.: A6 B% V6 F2 g7 S7 S- v
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;;;;;;;;;;;;;;;;;;;;;;
/ F3 v2 Y; z3 b;; Setup Procedures ;;: v. h0 T: d/ |! \% N+ M+ R
;;;;;;;;;;;;;;;;;;;;;;% `4 h9 B6 r) o4 R
8 c3 D- E3 t7 h* A4 c1 ?0 H, C;; Initialize the display by giving the global and patch variables initial values.8 s/ \& f- G1 E
;; Create num-cars of turtles if there are enough road patches for one turtle to
' C5 Q% _5 t1 c6 x/ W5 u;; be created per road patch. Set up the plots.7 x, d8 ?/ |, \4 X6 ]1 J* `
to setup
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setup-globals( ]% ~, w8 x; j6 x+ w: G
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;; First we ask the patches to draw themselves and set up a few variables; _. F- i! o; P9 y* Q6 y
setup-patches
& t( e% A- K `( E- f1 l$ S make-current one-of intersections* G7 N9 {4 q) R( I! F
label-current
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$ @( W1 l4 |6 a4 n% m set-default-shape turtles "car") G; E+ E4 ?2 q6 y7 P) c
: g K0 Q' I1 w: ~/ [ if (num-cars > count roads)# f+ [$ w& Z& I; Q7 f) h
[
4 h2 _9 N4 d! ]+ V% p user-message (word "There are too many cars for the amount of "$ w) O; r7 P W5 C" p$ V
"road. Either increase the amount of roads "
/ r3 [' Z' Q0 q1 K "by increasing the GRID-SIZE-X or ": Z1 r! e( F- ^
"GRID-SIZE-Y sliders, or decrease the "' w2 x1 I k( c* L6 m
"number of cars by lowering the NUMBER slider.\n"! d7 O& ^6 D- \0 L2 {
"The setup has stopped.")
+ K3 o! A1 k* G, ~, A+ p stop- l5 [" V2 J& z" i
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
2 |/ K! l% o4 R/ A9 Q- I) q crt num-cars0 w( {' m6 G0 q8 a
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setup-cars3 @! M f, Z, a. G. z! ]) @/ z
set-car-color
0 _! X F- b) X record-data
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& D" [, E# f3 n* P ;; give the turtles an initial speed
9 V. J" e' b( c. P" B* Y ask turtles [ set-car-speed ]
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1 _' `9 s' f9 E3 _5 P/ P reset-ticks# S5 T( b$ u( @8 c; N, L; F
end; H" x. x- [4 n! a! ] H
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;; Initialize the global variables to appropriate values
; q3 b/ Q0 G5 E; Eto setup-globals
+ R. n2 M: U) B+ b) d1 M set current-light nobody ;; just for now, since there are no lights yet
% F; T5 i9 }# S) p8 g0 { set phase 0
/ s) y8 o: u0 t, x1 ^/ d6 w( T0 p set num-cars-stopped 0; L) d) r8 e% H3 q& H2 [- s9 \
set grid-x-inc world-width / grid-size-x6 i2 M5 I# R1 Q5 A
set grid-y-inc world-height / grid-size-y
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4 @ P/ u) w( J# }, G ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary: J C% N' O/ n4 ^- t# S% `2 V
set acceleration 0.099+ T/ |; c1 g6 b8 i+ @
end
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2 d. o( |) `. K, p+ G;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
- @% w0 i& M# s3 p6 G* k7 w6 U;; and initialize the traffic lights to one setting3 r& g2 K# r: [5 d, `
to setup-patches$ a* i) A: h5 Q; ~) [/ H
;; initialize the patch-owned variables and color the patches to a base-color
* Z: X) t% n! b) E% g" B9 }2 M. L ask patches
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set intersection? false$ t5 |7 f. r# a$ o
set auto? false* ]0 I4 m a2 O$ g, Z
set green-light-up? true/ y2 G2 w4 f+ L' T7 g
set my-row -1
) q- B1 b- a$ R L set my-column -1
2 b9 H; z& }# N( g6 J' y set my-phase -1
* O% y" L9 B3 F$ B7 _1 T set pcolor brown + 3
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% @) w2 ?- Y( P( h3 W ;; initialize the global variables that hold patch agentsets
' G0 j) O# D/ v* \& m4 ^" ? set roads patches with
$ L* b( O" C; L" Q: K [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or( `! @6 ~2 {9 z0 k2 e8 ?8 \
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ a6 `3 S; P: c7 F% ?& G
set intersections roads with, [1 C& g8 H) f! N
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and/ f- e X6 t7 Z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 r2 Y, i4 X& @5 I3 u! M
$ a% j, w/ E8 a/ a' b' u p ask roads [ set pcolor white ]
4 \1 A4 z9 ]! {2 @$ @4 y# M 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?# _/ R- ]: }1 f0 o# H* W
set roads patches with3 e6 K: p0 U5 F& F4 F. ?
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or, Y U) x5 P' Y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ @) z g4 ?* U7 @/ Y- i
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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