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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, A5 @: T, B: i$ n
netlogo自带的social science--traffic grid这一例子当中,5 b( b9 t+ s8 N! m% G. |
globals, d! p8 P% K5 d h: w' R) W
[
2 g4 F, Q: g4 m/ H! K grid-x-inc ;; the amount of patches in between two roads in the x direction
* o2 j9 Q/ k1 R1 C grid-y-inc ;; the amount of patches in between two roads in the y direction; z/ d+ h7 b' q+ _0 y& e
acceleration ;; the constant that controls how much a car speeds up or slows down by if% A" v3 O* E- S4 x: z, w" c/ O
;; it is to accelerate or decelerate/ F: y5 P# m% Q$ p6 b: N$ W
phase ;; keeps track of the phase" H( g4 l+ v6 l6 z3 H+ K y/ m: b
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
+ {; p) e4 W* v7 L/ z7 w% P2 R0 a current-light ;; the currently selected light
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! `( c; l0 {) n% h) l ;; patch agentsets9 ~: y/ m& ~5 m p
intersections ;; agentset containing the patches that are intersections8 T4 I% _6 l# e6 x
roads ;; agentset containing the patches that are roads4 ?; @; e' J3 ] |6 Q) b) S
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9 U0 ~: ^5 S; [8 D% Y7 }& C; S) zturtles-own9 r U/ z8 Z" q. Y% Z t+ e( n
[
% C( u. C3 n' J speed ;; the speed of the turtle
4 Y; I$ D1 `2 J' N& @ up-car? ;; true if the turtle moves downwards and false if it moves to the right: B! D7 c" ?8 o8 p0 w
wait-time ;; the amount of time since the last time a turtle has moved! d2 M- k! ]9 n" z8 U2 k
]
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; g$ `9 s& h5 P( ?# D9 h* npatches-own
. ?0 K0 B+ j# E/ R[- _2 \; P2 T ]. `: q. v
intersection? ;; true if the patch is at the intersection of two roads' D% ^ z$ B0 U2 X+ G. m1 {
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
J. p: ^( O- b c$ p6 Z7 ?# F ;; false for a non-intersection patches.& p& `/ l4 d. c
my-row ;; the row of the intersection counting from the upper left corner of the
7 o$ e, z% j# Y Y. C9 v4 n ;; world. -1 for non-intersection patches. J% l5 }" L% J$ V) K: Q5 r+ g s
my-column ;; the column of the intersection counting from the upper left corner of the
9 X& E) w* P" y, z( l' d3 @ u1 z+ t6 c ;; world. -1 for non-intersection patches.6 _6 {6 W5 X q. F Q
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
3 s) m* w; |0 E0 X$ e+ \: U. V: U5 s auto? ;; whether or not this intersection will switch automatically.
- Z# g, C0 P& o# W" t. B ;; false for non-intersection patches.
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4 {& a9 ], l7 p* S) ^" V+ x
0 Y. u- y) S; s7 b& x4 V;;;;;;;;;;;;;;;;;;;;;;: I' M! s5 M. U8 r; I6 l
;; Setup Procedures ;;
4 S$ E" W1 ^/ h. F5 D. v: X0 o;;;;;;;;;;;;;;;;;;;;;;
8 e( U7 o- D6 s9 B" D. S/ ^; H A6 U
;; Initialize the display by giving the global and patch variables initial values.6 [7 W" E) x% u8 u& \* L# x3 H
;; Create num-cars of turtles if there are enough road patches for one turtle to+ P7 Y. W1 ?# R/ V; G, p+ r) n
;; be created per road patch. Set up the plots.$ [- w1 j6 z$ c8 h; C" ~) V# y; z
to setup
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setup-globals, R( y1 f" e S( S# y
) L! Y+ k7 u9 D9 h9 w# o/ y ;; First we ask the patches to draw themselves and set up a few variables( `; ~9 u( Z$ W5 J- j% A3 V. a
setup-patches% h$ L" W. S* Q2 v% Z# i
make-current one-of intersections9 c) ]% P4 u) |% o, R( \( x
label-current
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# I3 _% }" Y% b; Z/ n: g set-default-shape turtles "car"( u# `: F- `. P6 P. v: t( O
C4 \; n' n4 E% @! q/ H
if (num-cars > count roads)
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0 [8 _. r& ^! k7 l7 _ user-message (word "There are too many cars for the amount of "
; q* u1 C0 F5 e1 T3 T; m "road. Either increase the amount of roads "/ O& e4 ~6 d4 b! @& x4 z) [) s
"by increasing the GRID-SIZE-X or "
- F. _! `0 x3 F" x "GRID-SIZE-Y sliders, or decrease the "
5 k/ l* ^$ e! N5 f7 y "number of cars by lowering the NUMBER slider.\n"# _6 O* @- [) S
"The setup has stopped."); v- l, t) ]3 b% I
stop8 p2 q" V( ^& T7 [ o
]
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+ R: |4 | R) s# C9 _ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
# F5 ?0 F9 O. ]9 M crt num-cars0 n% O: Q) y. s& h5 c W, Y2 [
[7 S7 z7 _' c$ e; ]% A
setup-cars3 T1 L3 D7 u& o2 i" C, d) ^
set-car-color% t, n8 l) ]7 V6 ]7 A$ O
record-data' C ]: M" |. f8 Y( J
]" y2 l# ~4 H2 _2 M% s: K
* t r; @/ w1 P4 g ;; give the turtles an initial speed6 p p3 R! s/ @/ H+ v$ x) u
ask turtles [ set-car-speed ]' A3 z c" O# z
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reset-ticks) w# Q; T8 U. n& [6 S
end0 N4 M7 l( x3 j9 V! G \, \6 J
) }/ O8 ^4 W. Z& G s7 G% s6 {;; Initialize the global variables to appropriate values
% u6 E$ ]! e2 k" B- a: v) n$ Hto setup-globals
& m2 I5 D' h4 ?( @ set current-light nobody ;; just for now, since there are no lights yet. a9 A& W2 B( T1 p, `% y" v. L4 R" j
set phase 0. m7 ^# f9 H/ [+ o1 D
set num-cars-stopped 09 Y- m% \$ Y+ f- r' M' [9 s2 h% y% F
set grid-x-inc world-width / grid-size-x
+ s; V7 h# ~9 M set grid-y-inc world-height / grid-size-y
0 a9 ^# Z' j. A# S/ K0 i0 X. a7 R$ m, {5 n5 V
;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
9 s/ b- |$ X; l, P8 M0 U set acceleration 0.099
/ z( R; h. e; {- R$ D4 wend% c; p% j. s8 H) @* q1 `' T# R# C
. v X0 z! O7 g- ~% }- S/ X7 e;; Make the patches have appropriate colors, set up the roads and intersections agentsets,9 {. p6 g, r- Z: M
;; and initialize the traffic lights to one setting
( C; y# L& t6 ^" R7 Q4 l# o& zto setup-patches
/ w/ `6 k: z- ^* s. `4 {8 s ;; initialize the patch-owned variables and color the patches to a base-color
F# B, H- P8 T G ask patches
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6 a% [3 i% e7 T set intersection? false
7 t& L# _' T& p$ x) a( w5 m set auto? false
1 x1 d! v! E+ ^# }& d set green-light-up? true& J. `& k" e/ o' p* ]
set my-row -1
+ r) ^% J* h+ o: j. ~5 i# V set my-column -1, W7 B1 Q! T. T7 _, J+ k
set my-phase -1
3 _/ h2 c6 w3 j8 u& Z5 f+ [! R set pcolor brown + 3
+ P, t s) j8 K9 C5 J/ W1 r ]
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;; initialize the global variables that hold patch agentsets: a [% X+ `: k
set roads patches with
, C7 @0 n" j4 v! ]4 r [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or W7 ^) F1 t( x2 o+ R$ r( q, [1 F
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) R7 u0 V4 L/ v1 u set intersections roads with
! @7 u7 ?7 H, {# ` [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and% Y$ r# ^$ d# c: Y+ q2 I% ~# P ~% J
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 f, d; ^$ K6 r% [% Y6 D
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ask roads [ set pcolor white ]7 b5 X. F3 [: c, B* h3 y
setup-intersections' K5 E1 _; n0 R( @
end' n6 S e% t/ S
其中定义道路的句子,如下所示,是什么意思啊?3 k0 J" U3 b s( J3 E# ]- i
set roads patches with2 M% A7 H) a8 C: j$ V# g
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: T' }4 Q6 F2 j! A0 D& ~ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]) _8 O- }6 [1 G6 x
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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