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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。
& {* m! U1 s; [8 R" e" d. jnetlogo自带的social science--traffic grid这一例子当中,
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7 \+ D% |/ m4 x8 X grid-x-inc ;; the amount of patches in between two roads in the x direction7 E0 P1 A- O% S% r8 U
grid-y-inc ;; the amount of patches in between two roads in the y direction
; x0 M, D0 S# W: ? b8 K1 q8 h: c acceleration ;; the constant that controls how much a car speeds up or slows down by if
1 c; _# f" |. \# g ;; it is to accelerate or decelerate
+ i# h3 E! }. ?1 D: C2 v& x, V phase ;; keeps track of the phase
$ z1 y E. h# Z8 v num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
; I# ^* o6 D! X5 ~ current-light ;; the currently selected light3 D$ t+ w4 w/ [: M4 W. ]: f: b
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;; patch agentsets, ]- O8 Q$ v. n% z' f# D
intersections ;; agentset containing the patches that are intersections0 X p) N; ? \- Y& u5 O
roads ;; agentset containing the patches that are roads
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3 t9 U5 w5 F# P6 Yturtles-own. c7 F) _0 a/ ~
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speed ;; the speed of the turtle+ D/ p* J0 S1 S9 q8 d- d
up-car? ;; true if the turtle moves downwards and false if it moves to the right: {0 p) f1 Y- c3 P2 N
wait-time ;; the amount of time since the last time a turtle has moved" z; y4 S d3 W8 N
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patches-own& U6 Z4 I$ t% i3 ?) C
[
- S3 Q4 }! R5 O" m intersection? ;; true if the patch is at the intersection of two roads
; C5 m: O3 J4 \( G+ X green-light-up? ;; true if the green light is above the intersection. otherwise, false.( e& { v9 b. ^, ^
;; false for a non-intersection patches. Z4 s; M5 Q; v+ Y3 U' Q
my-row ;; the row of the intersection counting from the upper left corner of the- j7 q+ ` A( ~6 S1 M2 M% `
;; world. -1 for non-intersection patches.% A1 [6 z6 F+ h- O
my-column ;; the column of the intersection counting from the upper left corner of the
5 \: T6 {4 s: u0 S9 C, ^( c( h8 W ;; world. -1 for non-intersection patches.# A, t+ q$ _1 @0 v$ L9 x
my-phase ;; the phase for the intersection. -1 for non-intersection patches.5 X% r6 z" H* A+ R ?6 k& [4 L
auto? ;; whether or not this intersection will switch automatically.
- P. C' o& a- ?' e; Y% W ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;5 W/ u$ x5 ?) R- k3 u
;; Setup Procedures ;;
6 x+ v( h: x. G% I. g;;;;;;;;;;;;;;;;;;;;;;/ V, | T _1 t" C* q
6 C% _& D6 S# v# ~. g6 S;; Initialize the display by giving the global and patch variables initial values.
* q a( z. v0 e! O# {3 Y+ y7 n;; Create num-cars of turtles if there are enough road patches for one turtle to
, k! P2 N5 h( m* l" A, F& T;; be created per road patch. Set up the plots.3 O! `$ M3 h" |9 f- t
to setup
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setup-globals
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9 L. e; \$ a- B0 Y ;; First we ask the patches to draw themselves and set up a few variables
1 I$ v1 d' X& r4 o setup-patches% {" O& x; S( B3 c* a) e( G$ p0 d4 M1 S
make-current one-of intersections) I: h$ m @+ G* D
label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
" k+ H) L( `& ?9 A h1 N$ o "road. Either increase the amount of roads "
6 p' { B5 I9 |8 c6 T O# z "by increasing the GRID-SIZE-X or "- r* N2 V3 b N! z, c) y
"GRID-SIZE-Y sliders, or decrease the "
& ]; {1 u# C j8 @% @. q& p "number of cars by lowering the NUMBER slider.\n"* a- k: m7 O2 e+ M0 `' T3 z7 f0 ^
"The setup has stopped.")
& x ]1 O& _. e/ N! m4 I8 K stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
; [6 `) S% ]8 B7 m crt num-cars
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/ W, E5 y0 [; ~; A* c setup-cars2 k7 O" m" e# P* i2 Q% r
set-car-color% Y% N1 H, R c
record-data3 c: \: \0 {" X0 j! Y
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;; give the turtles an initial speed; m$ c4 M6 P5 O6 T" h
ask turtles [ set-car-speed ]/ U+ d( H/ P" V6 d( o1 U
% n, e+ ^* c; P* A! A3 Y3 ^, I1 z reset-ticks/ i" d" Q7 D- _! U3 i+ E
end
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5 \! ~& x6 w, O;; Initialize the global variables to appropriate values+ E8 g+ L% Q. |" O. j% C
to setup-globals# ~+ }) N2 h' h8 }
set current-light nobody ;; just for now, since there are no lights yet3 [ ?4 [/ _* Y8 b! H
set phase 08 ? [# j& c8 v$ u# U; `! o& r
set num-cars-stopped 0
* N% U' f- o& C9 }1 L set grid-x-inc world-width / grid-size-x) D! h2 E* \6 Y7 S% Y8 J
set grid-y-inc world-height / grid-size-y) G( M" r/ q. I$ Z& B+ f8 ]% _% _
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary% n4 ?$ H8 O9 d7 i/ O# U
set acceleration 0.099/ F* M+ _6 N' J% h9 a/ n
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,* b" u1 L0 u9 O( t7 S
;; and initialize the traffic lights to one setting
* n9 v$ [6 l) U! [. D+ Eto setup-patches
# ^( {4 ~) D/ r3 [, _; o ;; initialize the patch-owned variables and color the patches to a base-color
' f: A. B5 `" O, c ask patches
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# Z3 _: s" r* o+ S& A* n set intersection? false% l. V- w2 F" a1 ^- y8 e% c
set auto? false
% x& P8 w6 N3 E& t: p6 S0 q set green-light-up? true8 v0 V) ?, V2 T
set my-row -1: ~8 O5 N2 B! r k
set my-column -1
5 t8 _ s6 v) I3 z. R4 {# e# N set my-phase -1
! v! o/ s e, F" W2 |2 _ set pcolor brown + 3/ v" d# t9 d% P
]
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2 m, t6 t! L# Q& u/ r% ~( ? ;; initialize the global variables that hold patch agentsets F, [% `* ]* j
set roads patches with
' P" `4 ~$ C0 G* H( h [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
4 @7 B- Z5 o9 p( o (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
4 [7 N, l( ] A7 z4 O set intersections roads with
7 G; W8 c5 A+ V2 N c [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
( t( O3 t+ k f3 O" ^4 F/ [# s (floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 Y/ q; d8 T# U& c& |4 p5 w& t. J
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ask roads [ set pcolor white ]8 K- c7 v6 ^0 X( @' P" A
setup-intersections& |3 k. M/ j5 U. Q, F1 K
end! i( J- @. d6 |8 M3 t
其中定义道路的句子,如下所示,是什么意思啊?& G$ `6 G% g0 [/ t, o, M6 H
set roads patches with
4 v% E6 E- [" M, [8 g [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or# a6 N7 t5 b. o# m
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* u$ i8 i! x4 x9 P) ~" C1 e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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