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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。( j& O D; Q8 o% n( Q0 \
netlogo自带的social science--traffic grid这一例子当中,
# e/ Z" Q$ ^0 W$ c, dglobals
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' Y' K0 ^7 s- @6 R/ c grid-x-inc ;; the amount of patches in between two roads in the x direction4 ~5 G$ B1 r: W
grid-y-inc ;; the amount of patches in between two roads in the y direction
- |; P/ H! {& y9 i% X- \. R acceleration ;; the constant that controls how much a car speeds up or slows down by if) Q3 D# H/ Q6 ]1 T3 }
;; it is to accelerate or decelerate
: a0 X. [! _( _2 R phase ;; keeps track of the phase! s: D0 g$ ~* m9 e I' M
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
]+ q( g, V( C( |* a0 o current-light ;; the currently selected light. M$ o- \' X, F! T' D1 K* n/ X, {) I
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;; patch agentsets6 r! s- ~" X& e2 ]3 q4 B
intersections ;; agentset containing the patches that are intersections
3 r& J; l0 V5 Z) I roads ;; agentset containing the patches that are roads2 e$ F) q: F' n: C; P
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turtles-own
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& u+ e9 e3 Q! e9 T z1 G- Y- Q speed ;; the speed of the turtle
; l; d( c) d$ Z a5 ?; Y up-car? ;; true if the turtle moves downwards and false if it moves to the right
0 a( T: G& Q$ O3 v wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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7 [; t& u c' u7 R3 o1 o1 L2 x; S( X intersection? ;; true if the patch is at the intersection of two roads
3 T4 q% W$ P( c& v# p; T6 a green-light-up? ;; true if the green light is above the intersection. otherwise, false.
" D* r7 p5 E( J, D# } ;; false for a non-intersection patches.7 p$ \0 e/ D$ Q Q6 b+ l7 L7 [
my-row ;; the row of the intersection counting from the upper left corner of the
4 H. v( [+ b: b5 `& k ;; world. -1 for non-intersection patches.
- n& V9 j% b7 H0 v! r my-column ;; the column of the intersection counting from the upper left corner of the( h9 k" r" j: Z, A
;; world. -1 for non-intersection patches.7 F# t- Q0 b( T8 f0 R1 W6 r
my-phase ;; the phase for the intersection. -1 for non-intersection patches. p# v# a6 L/ T" g( {$ m+ h
auto? ;; whether or not this intersection will switch automatically.# l1 i4 h* K0 g* D
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;& u6 N8 G9 g. ?. o, W
;; Setup Procedures ;;
; S6 C \+ T9 o0 c- N( V;;;;;;;;;;;;;;;;;;;;;;4 [6 f2 Z# Q- i
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;; Initialize the display by giving the global and patch variables initial values.
# N' \5 c( |* d& h;; Create num-cars of turtles if there are enough road patches for one turtle to
5 C) w1 M0 S* \. w7 };; be created per road patch. Set up the plots.
/ u N, ~. H/ E% ^" Fto setup
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setup-globals6 p" M& p" C- O7 \
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;; First we ask the patches to draw themselves and set up a few variables7 N( |/ C/ E0 k1 t; i/ w. M9 {
setup-patches
7 I1 ]* L* }3 L' k- c* P# `+ o make-current one-of intersections
' b+ V6 N2 N" g label-current
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set-default-shape turtles "car"" v7 @5 [- S7 j( A( `# R7 ]) T
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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 "
& i! [4 _% r0 ^! F W8 \ "road. Either increase the amount of roads ": I# ^9 z' U9 v% B: u3 V ?
"by increasing the GRID-SIZE-X or "& h9 k1 t% Z1 ? n* Y% i
"GRID-SIZE-Y sliders, or decrease the "! V& @1 N9 I0 |7 z8 P. F7 Y1 G
"number of cars by lowering the NUMBER slider.\n"
# b& T [6 F. @2 ^, r "The setup has stopped.")& a8 g6 f& h6 D2 {7 o) s8 A
stop
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0 `" y s) H& V& m, g7 C ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
1 N0 \) l# w" L" q( ]% y' ] crt num-cars1 ]3 O! K/ l' z' h& m; T1 _ O; k
[
- v' r; P, `7 o' q! f setup-cars
s X: |, }: K set-car-color Z+ }. r6 ?) t4 D# s9 @3 m b
record-data; S/ R5 g# y p% @# T3 ]- y7 d2 _' b
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" o) `2 ]8 ` v9 p' V# B2 g/ t( i! u ;; give the turtles an initial speed8 x' j$ W; i4 Y% F K$ Q/ V
ask turtles [ set-car-speed ]
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reset-ticks$ ^; O, j% @/ _; H. {
end' e% M4 L5 K6 h( D8 i) J
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;; Initialize the global variables to appropriate values
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) F5 B- |3 n& Y+ _ set current-light nobody ;; just for now, since there are no lights yet# `- Q( g- ~: b
set phase 0- F! K V; E( `+ j+ j- O2 q
set num-cars-stopped 0. N6 W4 m) V1 I
set grid-x-inc world-width / grid-size-x
- c% Z: T3 `; D* s$ q5 a- J set grid-y-inc world-height / grid-size-y
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- n, D0 K' u4 V \ ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
( f m9 ?6 x ~$ K+ }6 m7 R set acceleration 0.099/ i& C' \" Z$ ? a' S
end+ q f5 {/ d! `$ k* K( R2 W
% S6 e: ~ ^4 c: `2 B;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
5 h. O) e) I+ ~) p' P" @ {, Q+ U;; and initialize the traffic lights to one setting0 U& E; b5 D$ b% K# H$ V3 q5 T
to setup-patches/ ^; J' j3 y$ x% L1 @) ^8 p$ L
;; initialize the patch-owned variables and color the patches to a base-color1 D: u: ?- z; u
ask patches
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2 s. f9 J% O R" z! {2 X. {, o/ R set intersection? false
( j7 S3 f7 c/ m4 i6 D0 |- x. t( [ set auto? false" ^, f# \5 ~+ ]7 S9 S. \
set green-light-up? true7 R3 s# C$ a; }9 W( y$ v/ f0 i
set my-row -1
- P$ h: g0 K+ L* u& A3 p set my-column -1
/ v$ X& e) U* `: `$ ?( g! t set my-phase -1+ ]% y* ^; L" x! A0 I$ M
set pcolor brown + 39 r2 n- n# r5 y! Q9 k" f W- n, m
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( }4 v" p8 A5 w5 v* T$ ~8 ] ;; initialize the global variables that hold patch agentsets( ~! ~6 w8 b f& B' |
set roads patches with; l5 T( n8 }& b9 v& Y. I4 X; [9 G) k
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or+ L# l2 F, {: T- v$ s
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]) {$ z: s v, r% f
set intersections roads with
0 S6 V+ @) _* ?$ [+ w, P [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and8 L$ a, }8 T# @+ ?* n$ m% @
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]2 s; h) a) d, J. z
setup-intersections
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& h4 Z- N! R# }4 j% a' i& R8 d其中定义道路的句子,如下所示,是什么意思啊?( p/ y# S, H1 z! f
set roads patches with
5 T9 y- m6 V# Z9 O0 f4 U% q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' D" ]1 F5 Z* C: W. h (floor((pycor + max-pycor) mod grid-y-inc) = 0)]% e. ?$ e0 m! X. e r
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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