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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。: b5 ?# A$ u4 c+ B9 l! X2 }
netlogo自带的social science--traffic grid这一例子当中,
( {/ G. X }4 Oglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction! @ V) j5 A4 `% y
grid-y-inc ;; the amount of patches in between two roads in the y direction
4 a& W$ {7 k+ R/ s, O acceleration ;; the constant that controls how much a car speeds up or slows down by if
( E& l% L% T9 h- M6 U$ | ;; it is to accelerate or decelerate. q4 q# u! L N% h! y p1 y/ c
phase ;; keeps track of the phase& D4 l( U, R( q" I I* r- X% A
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure' c1 ?- U. [/ F) t* p
current-light ;; the currently selected light0 p8 q/ e# j7 k9 q& g0 o
; o) M2 i4 n" L* x* M( i+ ^7 ] ;; patch agentsets. \8 v6 m8 A. q; ]1 n' i
intersections ;; agentset containing the patches that are intersections
. B- h' ~5 t" Q' g& L( a8 A roads ;; agentset containing the patches that are roads3 B6 ]$ m; ?4 _9 _
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turtles-own
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. w( a2 v8 g( _, Q( V4 A! |: r% X speed ;; the speed of the turtle
& P* |, Y' s. D up-car? ;; true if the turtle moves downwards and false if it moves to the right# j* |# `' Y& b# w6 d8 k+ G
wait-time ;; the amount of time since the last time a turtle has moved
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2 n/ j6 h( `2 [patches-own8 {6 o' g* n3 q4 @' q0 J2 z5 `" O
[
& X/ b2 F& V; Y+ c intersection? ;; true if the patch is at the intersection of two roads/ `2 J/ A/ p/ {
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
$ z" f8 p* G: E1 S' w f ;; false for a non-intersection patches.
8 i, _9 p- c( B% T) { my-row ;; the row of the intersection counting from the upper left corner of the
m. y8 H3 t6 {, q. F. P7 o ;; world. -1 for non-intersection patches.- c8 a) C8 L7 }. v
my-column ;; the column of the intersection counting from the upper left corner of the0 o: H, L3 x9 _& H% \- J* B6 W
;; world. -1 for non-intersection patches.
/ F5 y( I6 R- @. s* y my-phase ;; the phase for the intersection. -1 for non-intersection patches.
8 U# a* [4 w8 P) E auto? ;; whether or not this intersection will switch automatically.
2 h$ S; Y6 u% e$ ?6 ^ ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;* ~. i! x/ l" t2 q
;; Setup Procedures ;;
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( u8 R0 ?, ~. K1 W; ^! J( _;; Initialize the display by giving the global and patch variables initial values.
# c. X; ?# S' L! ~4 A+ Y7 v;; Create num-cars of turtles if there are enough road patches for one turtle to0 @9 f" p( o% @# {1 H
;; be created per road patch. Set up the plots.
* @ P. J; P# r$ n. mto setup
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setup-globals" Z* D2 g5 [ i/ I
S4 T' l8 A, }7 ~# x ;; First we ask the patches to draw themselves and set up a few variables
1 m# Z, n1 u( j9 Q5 ]) ?/ a setup-patches
7 W! D9 U3 [" [: G! u4 Z make-current one-of intersections
1 R& ^0 m0 X8 G3 Y# j label-current
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$ @* B4 l4 @4 \' `: [" p; S set-default-shape turtles "car"* q, `9 D' d- A8 ^( n
' N7 l5 ~( w, q7 g if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of ", A, t/ v; P- ~1 r7 @) ?
"road. Either increase the amount of roads "
+ o; y" C. Z' o. n6 p "by increasing the GRID-SIZE-X or "4 i7 Y# {$ ?7 } {. o( d7 {
"GRID-SIZE-Y sliders, or decrease the "7 ?* r L* {( a# L8 ~; Q/ ~
"number of cars by lowering the NUMBER slider.\n"
# u2 s+ G3 c% _+ K2 [( d, @ "The setup has stopped.")
2 T, O7 N& P4 f6 a2 T2 H: @9 ]% h stop
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' {$ O0 z2 ^. b' ?7 }2 z ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
2 F* s/ M. T% | crt num-cars
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9 `7 ]7 F4 g& v setup-cars9 ]6 _8 ?- a, p$ ?: f
set-car-color
- X6 k% e( Y7 \- T6 x1 X record-data3 l+ U8 w- U8 o/ @6 C% D4 D2 S
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" F/ S$ d" O7 n8 H, W! i I3 R ;; give the turtles an initial speed
" H6 Z8 N, J# N, m4 d) | ask turtles [ set-car-speed ]
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reset-ticks
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- e! Q' v- y4 h4 R2 |) \: ];; Initialize the global variables to appropriate values
" V" g# s; @5 i# q' Q5 h0 e: ]3 Pto setup-globals5 E$ B9 T: @/ F; x$ t
set current-light nobody ;; just for now, since there are no lights yet
. b: H8 S J: E0 G9 L+ H8 p& P$ L set phase 01 M9 m. Z) Q' R
set num-cars-stopped 0
0 x! m0 s2 l+ a: p set grid-x-inc world-width / grid-size-x
/ B# O6 _% W/ c( M( j set grid-y-inc world-height / grid-size-y3 m; \8 d( r: }7 d
7 m$ G* F9 `7 E4 H7 q) {1 w: X ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
) T) N8 u; V# E& b set acceleration 0.099
* ?% r2 G; Z: ]8 u- tend
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9 v8 C$ R: }# j" B' r;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
& T8 Z+ c. |$ E* Y( X;; and initialize the traffic lights to one setting
. O! I! v1 e+ @' d% Mto setup-patches5 q* m: o* G2 F
;; initialize the patch-owned variables and color the patches to a base-color. \0 T. f& N) z* [
ask patches
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) I0 |8 J2 Y+ J( t3 g set intersection? false
0 i' Z5 ?% E' m set auto? false: V$ f) S9 Z! D! D7 l
set green-light-up? true5 g' T, J. a) E
set my-row -1% v- f/ C9 |. C; R8 T6 Y; N/ l( o
set my-column -10 F; M) }7 e$ e& g; ~3 a6 \& u4 A
set my-phase -14 H1 x& B; v6 E: _6 e6 Z2 a* ?* @
set pcolor brown + 34 F* z' Y8 E$ S* T+ R
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4 n6 }9 |" p7 r5 Y- ?, Y3 \ B ;; initialize the global variables that hold patch agentsets
4 S: N2 b# J" N2 }1 F1 ?( s set roads patches with! F, u7 X, s1 R
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or; w9 w0 Z# u$ C
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ m1 n5 C% D6 V! i2 ^3 H
set intersections roads with5 K4 u2 E6 O( \
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and D; O& q( ?/ Q4 F
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]. b$ Z) x3 A9 t! u6 z3 ~
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ask roads [ set pcolor white ]
' g4 ^& {, x) e% ] setup-intersections
7 x3 S9 j9 l; I3 ^8 zend
. Z. n# Z4 K* h: i# |1 l& i; R其中定义道路的句子,如下所示,是什么意思啊?
( ]) }2 e$ X' w+ k* o set roads patches with W; i: O s# T: Y, D# F# H
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or3 v' z3 Y3 t2 D$ h
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 q' u4 L8 ~; M5 Y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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