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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。' B- g2 U. N. _+ d: B$ H' K9 f
netlogo自带的social science--traffic grid这一例子当中,
3 K# I4 r r) Hglobals
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! r: b* ]% ~4 R8 k6 d grid-x-inc ;; the amount of patches in between two roads in the x direction
& K6 l. ^2 g* H5 z+ G, {" b4 \. h" Q grid-y-inc ;; the amount of patches in between two roads in the y direction
9 M4 I" @* |# l% O( I% i8 v6 U acceleration ;; the constant that controls how much a car speeds up or slows down by if& D4 [3 i6 {4 x
;; it is to accelerate or decelerate
0 l5 m8 ]% h: O w phase ;; keeps track of the phase
2 a, V6 K9 @. M num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure2 g" l ?# B! i% }
current-light ;; the currently selected light
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5 {* `, U. P1 X* H4 U6 e4 k ;; patch agentsets( _8 N: g0 I6 j9 V. z' F: ]. a
intersections ;; agentset containing the patches that are intersections
+ t8 C3 Y/ Y( A4 r roads ;; agentset containing the patches that are roads
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, z' ~; B- t7 ]turtles-own
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- l6 X; N( ^. J3 N. _4 E) G speed ;; the speed of the turtle
$ a0 f+ Z( ]0 i6 ~) S up-car? ;; true if the turtle moves downwards and false if it moves to the right8 h: g: O' ^9 t
wait-time ;; the amount of time since the last time a turtle has moved/ o; t& @8 s Q, X% f
]& b# W% W0 ~7 }+ b
$ m, ?: t% o- Z8 Z, l, b/ k5 Dpatches-own- E* i6 o5 U8 F
[
# X2 y: C3 @& M5 r intersection? ;; true if the patch is at the intersection of two roads
* H- Y: u G5 o8 @6 p green-light-up? ;; true if the green light is above the intersection. otherwise, false.( G$ b- l: Z+ d1 Q7 t
;; false for a non-intersection patches.
7 v# W. u r. \& t7 B4 b my-row ;; the row of the intersection counting from the upper left corner of the
) i" w; D! r5 A9 h, \! ~ ;; world. -1 for non-intersection patches.
) {/ H. k0 a) u my-column ;; the column of the intersection counting from the upper left corner of the/ L$ q0 O" [2 R4 K. Y( \9 i- ]* u8 a& l
;; world. -1 for non-intersection patches.
$ c* A2 u* l) M5 j! t- z my-phase ;; the phase for the intersection. -1 for non-intersection patches.
* Z3 W$ y) g& ^' u+ N auto? ;; whether or not this intersection will switch automatically.
' p& \4 t0 r% W Y ;; false for non-intersection patches.5 _. p) W8 P. X, m
]
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;;;;;;;;;;;;;;;;;;;;;;
7 M+ v3 q" C1 u" Z+ v5 h;; Setup Procedures ;;
5 [0 } @, u7 o6 b) H7 R9 V;;;;;;;;;;;;;;;;;;;;;;1 i) q/ k+ h. b/ `4 U" h
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;; Initialize the display by giving the global and patch variables initial values.
. @/ a. J$ j9 b( n* @;; Create num-cars of turtles if there are enough road patches for one turtle to
( D4 F$ \8 }/ K. K' J: n;; be created per road patch. Set up the plots.
2 s" G3 T' M. }- \to setup
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4 n5 C+ j" g9 K$ k$ E setup-globals& \1 J$ ^! P% u& p8 o7 {
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;; First we ask the patches to draw themselves and set up a few variables. k" d( p2 ^. c9 K( H
setup-patches
' D3 y; l5 h+ e0 Q( s; |3 U make-current one-of intersections
0 I" J: C" L3 l: G, n label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)6 P7 `; L/ B; S
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user-message (word "There are too many cars for the amount of "
2 A! [% U( \% G6 y+ j8 {- M "road. Either increase the amount of roads "
5 P# m& e! Z& ]! @ "by increasing the GRID-SIZE-X or "7 Z6 M( o9 \' \7 O- o
"GRID-SIZE-Y sliders, or decrease the "$ K" v0 o' X. }
"number of cars by lowering the NUMBER slider.\n"
% W4 ^& V, |9 D/ R) c4 w "The setup has stopped.")1 J! g& \7 `, d5 j. W* [
stop! o1 j2 @- { m, M* _6 U1 I
]
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6 f6 K! ~) `, _/ L! h ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
# ]- ^4 n- d. ?* m crt num-cars( _7 b: n' g4 {
[
3 E, H0 D6 b) I setup-cars$ s, N/ F9 M9 B# }: Z0 Q
set-car-color
- K( b4 X, Q: h record-data
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;; give the turtles an initial speed
1 ]% j, ?0 {' j5 U( c3 V ask turtles [ set-car-speed ]
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reset-ticks2 h9 G# t& B; P" Z5 |( j3 g% }) x
end
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( t- u: a' O: V, S2 U+ h$ [- ~0 S;; Initialize the global variables to appropriate values, \4 x+ o* A" Q8 b. Q6 \
to setup-globals
0 i1 w$ ~5 W3 r set current-light nobody ;; just for now, since there are no lights yet
! c9 S3 y( `, G7 B6 r set phase 03 ^! S" N A3 W8 j, L) G1 ]
set num-cars-stopped 0
! I5 ^+ l1 c/ c# f+ x6 p' @ set grid-x-inc world-width / grid-size-x0 z9 X$ b- X" m
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
+ j' ^9 `, x- y }" f+ P0 ] set acceleration 0.099
& M: P( E0 I9 D, B0 g6 C) Cend7 {& i7 h: B% m C; C3 f2 s
, B0 M; e$ @8 H. q" g: l;; Make the patches have appropriate colors, set up the roads and intersections agentsets,9 B! u B, F3 G3 X. A# b: h
;; and initialize the traffic lights to one setting
- H0 y! i, {, f5 i/ Vto setup-patches1 [1 b$ s2 x$ W ~7 B
;; initialize the patch-owned variables and color the patches to a base-color) z4 d$ I) l8 e+ N7 @% f
ask patches
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: p9 ^ P9 I, S. m( i set intersection? false5 M, W# X3 P: J
set auto? false
" g# c- p' Y, Y set green-light-up? true. @3 D; O/ x: H1 ?/ C, a( v
set my-row -1
" D8 F b1 @2 x- j set my-column -1
8 c7 O7 D$ n% Y E4 o set my-phase -1
6 H) D& G* C1 O0 s set pcolor brown + 3
8 V2 @# F4 Y" I7 c0 p: B5 h ]
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3 V. _! O S- k3 p+ B9 _# G ;; initialize the global variables that hold patch agentsets7 q& `1 F. A/ A# H: g3 |2 f8 o
set roads patches with. w# v8 ?1 q6 m# t4 g
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or5 @* ]3 W6 M& e+ F: c
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 h( w' G( e5 C+ x: R set intersections roads with
+ C- d. F$ D! g+ U4 T [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and) l# z0 Y J4 T& d
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
{/ p' D) w: v! b: |+ k setup-intersections
9 a0 l" o) p' X1 S" ]8 \, \5 |end
# P1 p8 ~( O* T, J" s8 ?其中定义道路的句子,如下所示,是什么意思啊?
: K# A. \& |4 |! C% v9 a set roads patches with8 u0 K# N, U2 y7 ^
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or/ S0 | z9 S! u2 e5 h- i
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ G% S" X& `5 K8 q! |' Q3 }
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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