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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。% D! i9 `6 N8 Q: p
netlogo自带的social science--traffic grid这一例子当中,
7 d5 n4 o$ |0 Eglobals
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9 x1 d5 Q# t0 O. H. q grid-x-inc ;; the amount of patches in between two roads in the x direction6 D. c* P% X1 h/ Z+ ~: F
grid-y-inc ;; the amount of patches in between two roads in the y direction
d0 ^! E6 t- E7 t% K acceleration ;; the constant that controls how much a car speeds up or slows down by if
- F; v0 ` N4 P' G% ]( E ;; it is to accelerate or decelerate: A, N0 |$ j& m3 S
phase ;; keeps track of the phase
+ e2 L: h6 N7 @) _ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
- f# q$ P% X, w& k' c current-light ;; the currently selected light' Z, b/ b" v4 _( j; V8 ?
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;; patch agentsets: I S- g9 p2 w# _, l) k$ I
intersections ;; agentset containing the patches that are intersections
; d' _" H+ y: n5 x+ K roads ;; agentset containing the patches that are roads
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7 z9 T. E- M# Bturtles-own4 z6 l. f- n7 \$ d
[
& E l, i3 k5 o! j' x speed ;; the speed of the turtle
: \& y. i3 |+ W up-car? ;; true if the turtle moves downwards and false if it moves to the right6 n9 b3 I& p% X1 D4 l
wait-time ;; the amount of time since the last time a turtle has moved3 r1 m; K9 U0 j' C) z4 F
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
4 D- v% b3 ]; K green-light-up? ;; true if the green light is above the intersection. otherwise, false.
$ g1 b8 e3 _& h" O& @# Y ;; false for a non-intersection patches.
! o* i* e- q5 y, ~: H my-row ;; the row of the intersection counting from the upper left corner of the
2 m' g- V5 V, t. B" ?% E ;; world. -1 for non-intersection patches.
6 f Z- v U# B' s4 } my-column ;; the column of the intersection counting from the upper left corner of the
( T& e$ z( j( b* J* S$ X5 K: X" {5 e ;; world. -1 for non-intersection patches.
1 G5 m* o/ Q1 Y& _ my-phase ;; the phase for the intersection. -1 for non-intersection patches./ ]3 A9 c! w6 |
auto? ;; whether or not this intersection will switch automatically.5 ^% F' j8 O2 z. L4 G" b4 d; x
;; false for non-intersection patches.
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5 Z' i5 i2 U. l;;;;;;;;;;;;;;;;;;;;;;' A, q2 W! p# r; a- |2 Q
;; Setup Procedures ;;9 [ n( e" Y6 V) r4 e' m
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;; Initialize the display by giving the global and patch variables initial values.7 V* ^ c5 v2 {4 d( e6 }& t, u
;; Create num-cars of turtles if there are enough road patches for one turtle to, m; {1 h9 l& W4 K
;; be created per road patch. Set up the plots.! Y. K7 K( s+ j6 F s
to setup, Q( i& C# d" f' Y1 t
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setup-globals
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3 B8 o/ P8 ]* y; Y) | ;; First we ask the patches to draw themselves and set up a few variables
5 `- m8 u" |9 F G setup-patches0 W; l; f* |( V5 w) c
make-current one-of intersections; X: i4 c" G6 y5 W5 b4 ?
label-current
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7 @. _: c* @" U# Q- Z set-default-shape turtles "car"6 ~$ N: P* j- D
6 M) B* e. S K. g; ~: c, V7 {5 O if (num-cars > count roads)% Y0 N6 `5 b! R% X8 R3 f+ k
[
$ O! t) m- r- Q: U user-message (word "There are too many cars for the amount of " J- I+ K& Z% q- t) |
"road. Either increase the amount of roads "5 v. A1 G* v: O8 d8 C& g5 R& \7 d) r4 e
"by increasing the GRID-SIZE-X or "
) y- J _# T4 c& W "GRID-SIZE-Y sliders, or decrease the "
G% X G) |0 ?8 e "number of cars by lowering the NUMBER slider.\n"
1 o7 u' Q: J5 T V6 }# M "The setup has stopped.")
4 |2 q2 _! g/ q4 h& \ stop
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+ D6 q j- t0 T8 O! Y4 @" S4 \ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color3 F: S4 t; E7 V0 i
crt num-cars
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' N2 L4 M1 _: Q9 L6 O setup-cars
. w1 o2 U. H( j* ]0 e0 ?: K set-car-color; v3 c' I7 ]5 \ p; ~
record-data
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# P9 _& W# b4 h# }- c$ R$ l v ;; give the turtles an initial speed
4 l- c& u* c2 E6 Q% p" _ ask turtles [ set-car-speed ]
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reset-ticks. \& W/ L" G: r, H5 e8 c
end# K: `* a H( p- y2 n* o
. F4 t" S( }! A" b3 P& O3 ]9 R;; Initialize the global variables to appropriate values+ z% V( ^! p" a. S
to setup-globals
, S. S" m) p( l# P0 s3 q) w1 X set current-light nobody ;; just for now, since there are no lights yet* h( m3 j& E- o! m! b0 |9 C; `4 Q
set phase 0
& F, I) D( h& A0 p" D set num-cars-stopped 0. w% ~: g; v M% ]+ O
set grid-x-inc world-width / grid-size-x
6 i2 Z& o( o, X) J 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& z/ k' y( S. H) n
set acceleration 0.099
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6 Q9 B' m+ a7 L$ x;; Make the patches have appropriate colors, set up the roads and intersections agentsets,, s3 A' |- a/ _: U y% Y
;; and initialize the traffic lights to one setting
! b. _# [1 t. q9 Nto setup-patches Y+ }( N$ J1 T) M
;; initialize the patch-owned variables and color the patches to a base-color
) U- e3 e2 A. E/ q/ ^ ask patches* F0 h* S- H6 T; N/ b% J6 L* W& p
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set intersection? false1 L& U6 ~$ _: g- j3 `; O1 z g
set auto? false/ e0 E6 N t( s) f9 G6 n
set green-light-up? true
' ^9 w2 f% r- s; i5 \ set my-row -16 d, o; r$ p3 H! c4 E# y3 }
set my-column -1
. O3 C7 D: c7 t/ |6 t set my-phase -1
+ [% z& A) q; ^" e+ T set pcolor brown + 33 [8 s# u3 {6 t/ F' {8 U. [; W
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;; initialize the global variables that hold patch agentsets
) L$ z% `$ p/ r+ \8 w set roads patches with* j/ R- R2 ]: u& x
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
* X. S! O( z1 D: n9 u# l( a& D (floor((pycor + max-pycor) mod grid-y-inc) = 0)]% _3 `9 W$ g' Q
set intersections roads with5 V: v3 y f S" L, b6 S
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
0 Y. H6 E- l5 E3 H (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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1 v# x/ V- h \6 ]" S! u# J2 A% m* J ask roads [ set pcolor white ]& x1 x6 n. o7 [% o- g' {4 n; ^1 K
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?
9 L1 N q0 G1 n& _ | set roads patches with
+ U. G$ p$ r% o6 P# Q& P' `2 K [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: k$ E% P7 C- D. ^2 ? (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) H; Z& h, n) i, z% [: t% z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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