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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。
2 l) v" B% E- S& h1 W wnetlogo自带的social science--traffic grid这一例子当中,
$ C& s+ S" h; T" q" Y0 x1 ~globals2 E {* Z, V# M2 q* v7 O8 Z- L
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grid-x-inc ;; the amount of patches in between two roads in the x direction4 k7 s$ j) w0 q) F
grid-y-inc ;; the amount of patches in between two roads in the y direction
- b; Q$ U! z& F) c& M" |# G acceleration ;; the constant that controls how much a car speeds up or slows down by if0 B8 c; A8 U$ U5 V/ N4 d# V( ~
;; it is to accelerate or decelerate% k, N% ?6 s; `8 i" {# n+ x
phase ;; keeps track of the phase
; d/ a. l3 _3 i% H num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure |7 T1 [9 g! p- z! l8 x% p' t% C
current-light ;; the currently selected light
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;; patch agentsets5 i9 S# w2 P% l2 }4 R
intersections ;; agentset containing the patches that are intersections4 Z) l: K2 H8 S; P
roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle
# t5 E w" j+ h6 o% `4 A# a up-car? ;; true if the turtle moves downwards and false if it moves to the right+ x( }$ ?6 X8 g
wait-time ;; the amount of time since the last time a turtle has moved4 N1 W4 p6 m* o* M( m3 K
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads& e1 O. p) M7 f' s
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! n5 w: }3 Q1 w) R/ C: f ;; false for a non-intersection patches.1 d) ^0 Y% ?+ L' `3 n6 t% \
my-row ;; the row of the intersection counting from the upper left corner of the2 x. @3 n: h: O' t& e
;; world. -1 for non-intersection patches.
8 J2 k9 o+ B6 e; Y( B$ h+ |& Q) w my-column ;; the column of the intersection counting from the upper left corner of the$ X( N1 B0 R$ l
;; world. -1 for non-intersection patches.! u4 b6 `" d* Y3 h$ S- r2 F9 {
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
! [* w$ G- Y& {+ ]( L auto? ;; whether or not this intersection will switch automatically.5 f+ v& D- W4 i/ r( r7 y
;; false for non-intersection patches." y; n% p O# h- x$ O
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% v% f2 Z6 m+ L5 d1 g;;;;;;;;;;;;;;;;;;;;;;
4 p0 C( w9 G: R7 `8 Y;; Setup Procedures ;;( ~8 O; U. N8 N' s% S& D+ [! A. _
;;;;;;;;;;;;;;;;;;;;;;0 L8 @: N8 ~; V) E2 R+ y; l, ? u
' k+ g5 h5 v# ~. I;; Initialize the display by giving the global and patch variables initial values.% Q/ h5 G# _4 j6 p# ?8 ?
;; Create num-cars of turtles if there are enough road patches for one turtle to
6 j* i: S8 e( i: R2 ^' n' Y0 k( s. [;; be created per road patch. Set up the plots.
: k' b7 F$ m1 r0 D; h$ Lto setup( B h3 X' i" C/ `
ca
9 y2 C" B7 X3 S [' _ setup-globals2 q) |+ c W0 y5 T( d* d
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;; First we ask the patches to draw themselves and set up a few variables& C6 i$ T8 t+ H& z
setup-patches
0 J/ V8 A( l9 H2 @7 l% G6 ` make-current one-of intersections" b M Z7 J5 O; S |
label-current
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set-default-shape turtles "car"' t- G6 ^/ F8 K% ^) y5 g
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if (num-cars > count roads)# N4 j. I+ d& { k1 c' f% P
[
8 y j' D- w0 H) L6 M, | user-message (word "There are too many cars for the amount of "
1 }1 G0 {" ~9 ~. [9 B/ b G$ V "road. Either increase the amount of roads " v; q. E) R# l# C) c: n7 j
"by increasing the GRID-SIZE-X or "
4 i8 ?! I* }. Q& _ J0 M7 P "GRID-SIZE-Y sliders, or decrease the "' ?5 @0 Q' d& s
"number of cars by lowering the NUMBER slider.\n"
o' Z. f! k* G" J- o+ X% O# h# a; s. } "The setup has stopped.")
: K) q; J3 E: v$ C# u) z stop
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& ]1 |( {6 ?) g' H& N/ v ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
1 s) W2 n" R& S ]$ Y crt num-cars
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1 ^3 R7 O0 V# T0 \( @' m setup-cars8 B% a: A/ X/ T5 Q
set-car-color8 |9 h0 V# E; u! o; X
record-data
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;; give the turtles an initial speed% _8 A1 a$ e8 O( X) Z4 U; ]
ask turtles [ set-car-speed ]0 m& ~7 N6 s: A- q) L
1 h0 D: p% t3 f reset-ticks
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;; Initialize the global variables to appropriate values
4 b( _& ~8 b+ ?7 C P! R0 e% ^to setup-globals: S1 y; E# e+ j0 r4 p
set current-light nobody ;; just for now, since there are no lights yet$ p5 E: u7 F" C0 t, s1 |$ S
set phase 0. J4 O' \, e. M; `
set num-cars-stopped 0/ ~% n5 A' A" O* `' ]2 _ K6 b7 ~
set grid-x-inc world-width / grid-size-x
5 t+ S% o% }9 Z+ R/ o9 R( ^; o set grid-y-inc world-height / grid-size-y
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L2 z- r- z) n# t& P ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
$ p) B1 ?; k/ v+ J' D' Y set acceleration 0.099
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: w4 a9 O4 A9 G0 J) ]* [( Z;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
. w0 c7 a$ w" d;; and initialize the traffic lights to one setting
" u, c5 s, I$ {9 Pto setup-patches0 P0 p6 x/ t, H$ T8 [
;; initialize the patch-owned variables and color the patches to a base-color
" [1 K$ I; K- W: x ask patches: ?, N: N. G1 B1 L
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% y8 W Y8 i& N& w, I set intersection? false
: `4 ^6 q* P4 [) d& T set auto? false
" z" M9 E. Y( y7 c( s set green-light-up? true
% {3 `7 h- C* B j0 H set my-row -1
* L" ~7 K5 |6 p; S8 ~# T: E set my-column -1
/ b0 a- Z2 i% j9 Y- o. L set my-phase -11 i4 y* p) y6 I5 M8 E
set pcolor brown + 3
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: i# ~% v$ p9 h7 R% y ;; initialize the global variables that hold patch agentsets, i0 \8 `% c. ^4 _% N
set roads patches with
0 b: w! E0 ` l [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or b9 s B! |* {1 n; K: R2 n# u; u
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ t- X% R3 O0 e
set intersections roads with) u& {) J1 N4 ]7 i$ i% y
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
& t+ l% G1 D; U; }" A (floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 e% ^" r2 }3 u. E& X
1 v/ R1 [; d8 t9 K8 N ask roads [ set pcolor white ]# \3 [, H4 A5 k' h
setup-intersections( f6 [1 ~" c$ \6 E' F
end
4 X) Z9 o' b( \+ t5 U* M: @9 t其中定义道路的句子,如下所示,是什么意思啊?- i' d3 K/ Q% U
set roads patches with
" o+ A4 ~+ J* O) X [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
* Q3 B+ Q6 b3 J3 c (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 ^( F+ L. G, g9 e- C B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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