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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。
- t5 `" H" P$ Z. d0 b# H' enetlogo自带的social science--traffic grid这一例子当中,1 z* {: y" q9 q
globals" B# u( m- d5 B5 m$ D
[
( h! U0 |5 y/ W1 h9 C5 T% o3 ~ grid-x-inc ;; the amount of patches in between two roads in the x direction# |0 V" Q" J0 R0 x3 u
grid-y-inc ;; the amount of patches in between two roads in the y direction
9 n4 K9 E' z* j ]& f! Z8 M x6 [ acceleration ;; the constant that controls how much a car speeds up or slows down by if
. K. ^, S" ]" ?. [3 w ;; it is to accelerate or decelerate7 ]. t9 t0 o, L+ P: L
phase ;; keeps track of the phase
: }: f/ m8 B# p% h+ [" y( `. i( | num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
) D+ ]) k+ M; ^3 |) W/ P current-light ;; the currently selected light
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/ Q4 }5 [1 g8 x' p9 m% n2 E ;; patch agentsets- S5 S k0 m. F) `) d) p
intersections ;; agentset containing the patches that are intersections: I+ a# t: f. j; r
roads ;; agentset containing the patches that are roads$ E3 [; X& w' x0 o Y
]
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! _' w8 o9 |! l1 Zturtles-own
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speed ;; the speed of the turtle
0 X! J) u8 T& ^9 F up-car? ;; true if the turtle moves downwards and false if it moves to the right) X$ H, E9 C$ G- C# Q
wait-time ;; the amount of time since the last time a turtle has moved5 H* @, V0 I! s6 ?& R
]
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patches-own+ J* ?9 u9 b1 |9 x
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intersection? ;; true if the patch is at the intersection of two roads- y- S H* X4 t5 X* g
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
0 j8 z9 b: W) t7 e2 ~+ L. l! ^& E ;; false for a non-intersection patches.
( l: M( h6 \( z" W1 N my-row ;; the row of the intersection counting from the upper left corner of the
/ _/ i- D- @$ |# | ;; world. -1 for non-intersection patches.
J N0 O$ Y$ E( w my-column ;; the column of the intersection counting from the upper left corner of the
b6 b& I' \. g3 J2 E/ l1 p ;; world. -1 for non-intersection patches.7 R' k5 v$ d/ T' L( h' o
my-phase ;; the phase for the intersection. -1 for non-intersection patches.& }% Q8 I: _+ l6 A P9 o. C
auto? ;; whether or not this intersection will switch automatically.
% n0 ^% v$ h. s ;; false for non-intersection patches.
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& I+ ~# B% f1 X9 M' N;;;;;;;;;;;;;;;;;;;;;;' n4 h: y- Z) x( h- e& F
;; Setup Procedures ;;( T0 Y1 N2 G4 T; M
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
+ G: ~ {1 w$ G( W;; Create num-cars of turtles if there are enough road patches for one turtle to
8 B3 [" U. N; ]8 S) t/ [;; be created per road patch. Set up the plots.
( _1 w" k( Z6 F; P0 s/ o% sto setup$ U' X' c7 j8 `& c
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setup-globals1 A N2 P# }* i$ x
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;; First we ask the patches to draw themselves and set up a few variables( q7 l/ [% f4 ]! d' u
setup-patches
; ?: j9 w; N ]: f make-current one-of intersections! x) b3 F. w- ^* N) R# L1 z" J6 _! _
label-current; U; X' v- p0 _# E* y
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set-default-shape turtles "car"
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if (num-cars > count roads)/ _0 g* O! o; K+ `
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user-message (word "There are too many cars for the amount of "- N% Q) {3 d' V' @9 U
"road. Either increase the amount of roads "1 ~: x2 g! Q9 P' b+ P
"by increasing the GRID-SIZE-X or "$ i3 D0 r8 j O0 x6 I7 S
"GRID-SIZE-Y sliders, or decrease the "/ N0 Y- S1 Z/ U ^& u' T. X
"number of cars by lowering the NUMBER slider.\n"
3 N3 S: y! h" m "The setup has stopped."); ^* P0 P+ Z8 r# w
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
& w/ p' C3 p" d9 I. J- g% R crt num-cars
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2 @$ a( ?: q. k. U7 L: ^* z( Q* y setup-cars3 m. W1 j+ q. Z. C; |8 ]
set-car-color! @) r4 r( X' B' P$ G
record-data0 {2 W$ g5 `& b/ D
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;; give the turtles an initial speed
5 d6 x! Z6 w0 k- C, F6 U ask turtles [ set-car-speed ]
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reset-ticks& | t* y7 a8 K @% n+ }
end
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;; Initialize the global variables to appropriate values/ ~5 V7 {; s" e% J* w
to setup-globals9 F" s& p4 N( G2 u' z
set current-light nobody ;; just for now, since there are no lights yet9 `4 M5 @6 S) w
set phase 0. `0 N, {( X* d$ @9 V1 U3 c
set num-cars-stopped 0% [9 V! @* Z6 U" Z! ^
set grid-x-inc world-width / grid-size-x. E- Z; ?# v& w5 ]5 D. m/ B2 [
set grid-y-inc world-height / grid-size-y3 C6 R- d) f$ g% F1 V! e" V
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
) o6 @# |5 S" d2 A% W set acceleration 0.0999 Y) U: e4 H- S9 D: {$ F' ^* d# p
end
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; O" ~6 o. `% k7 {% a3 [;; Make the patches have appropriate colors, set up the roads and intersections agentsets,( t4 X4 O2 d+ S7 g! _; c: A
;; and initialize the traffic lights to one setting0 r1 u* b7 b. P; o9 T
to setup-patches
! ^- x6 I- o2 x; M ;; initialize the patch-owned variables and color the patches to a base-color' t5 V. f9 @- e% n8 Y) I2 C5 A& V
ask patches5 ?* L: O7 a1 V) n& a
[
$ [0 R; ?& {1 S3 F6 k8 ?2 Q set intersection? false
" K2 m4 @) q' G3 t4 X/ X: r set auto? false
# x5 q. m( G: g+ @* h set green-light-up? true8 X9 v* h1 {) G" _1 k6 {6 _8 F8 \
set my-row -1+ w% k* L5 C ]$ r+ W6 w1 {
set my-column -1; `2 g5 z( a( W- @$ W: d
set my-phase -13 l( T$ I0 Z! V0 T$ [, c
set pcolor brown + 3" P4 n# I$ j3 F8 ^- F& G0 S
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6 c! m; V/ r) Q8 B- H+ V, E7 o3 h. G ;; initialize the global variables that hold patch agentsets3 w4 b8 \4 C9 X6 i6 ?1 c; e
set roads patches with
* h: P5 n( m1 `. f; z. h [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: F7 G+ s# }" c: f% M- I8 j (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
- \$ w# p4 t( Q1 e8 |" B9 @' t. H# b1 r3 P set intersections roads with
, ^; Z) X7 D' D% i [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and5 y7 i6 G7 F9 Q- s, F% c- U7 c0 l
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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5 q: P. n3 `, |" C8 h ask roads [ set pcolor white ]- D* M+ W: c8 C* B
setup-intersections8 V# J# [8 V9 I" s* W( K
end
* d, y Z+ u H. c其中定义道路的句子,如下所示,是什么意思啊?
6 W, S& ~2 i1 w0 o set roads patches with2 ^5 A* S+ M: w. K& L) a: a- L
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
2 D; R9 L# X+ e+ J! P (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
! j, \! G( y- z8 n7 t/ {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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