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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 @, I. ~" Y7 c6 }7 @8 y
netlogo自带的social science--traffic grid这一例子当中,
& B; b0 m! ]& Q% T2 T: {, C' q0 M0 wglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction% G. z0 D* d, q1 D
grid-y-inc ;; the amount of patches in between two roads in the y direction. f) _% H) S- G% u4 B3 k
acceleration ;; the constant that controls how much a car speeds up or slows down by if
* r) I. R0 o& x# F- A% c' m2 R ;; it is to accelerate or decelerate
* s$ x4 y* s; x7 Z6 f7 O% g, b phase ;; keeps track of the phase
- d1 i0 i; S2 j+ O$ C num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
6 y. }0 s2 ?0 L3 o current-light ;; the currently selected light
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& a' R2 x1 ^8 w' o7 Z; P6 v ;; patch agentsets/ ]+ e$ t$ k" L
intersections ;; agentset containing the patches that are intersections
, v# x- `7 @& U" z/ a roads ;; agentset containing the patches that are roads2 N* @' r3 e& c, B
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* S% X: Y6 X2 G* F; g$ _turtles-own3 {# f5 Y c; T# ~" h F' ^7 E: W9 U
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. Q) D# C' b& ? speed ;; the speed of the turtle1 }! z$ N4 k( i8 ]( R1 \* J
up-car? ;; true if the turtle moves downwards and false if it moves to the right
" [' s0 r$ b4 g0 l9 p( d. E& W wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
% j! j6 W; `' y8 P* X green-light-up? ;; true if the green light is above the intersection. otherwise, false.; e/ Y/ c! y5 X
;; false for a non-intersection patches.
8 s8 W+ X- n* @/ e my-row ;; the row of the intersection counting from the upper left corner of the/ C+ K9 R, X; v* E: r/ M8 ~- x
;; world. -1 for non-intersection patches.
0 ~8 Y0 ]3 Z4 q+ @* d% q) ?! y my-column ;; the column of the intersection counting from the upper left corner of the
' Q$ f1 e9 M6 p ;; world. -1 for non-intersection patches.
% C) ^0 ^3 J( C: ~' H my-phase ;; the phase for the intersection. -1 for non-intersection patches.: C( H* U# {; O" |
auto? ;; whether or not this intersection will switch automatically.
) u# U3 f) |8 @/ X7 A. |' H ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;, \- u* P$ g5 O; j9 r& t' u# ?- ?
;; Setup Procedures ;;
* k6 W* c7 b4 w9 c/ n# S, U6 b+ a" y;;;;;;;;;;;;;;;;;;;;;;' A; T# Y9 S$ [5 o# O! j
* x( r# w7 m& ~( \;; Initialize the display by giving the global and patch variables initial values.
+ v" T2 y8 x( a, @, l S;; Create num-cars of turtles if there are enough road patches for one turtle to5 g0 c, O, r1 Y) ?4 R! X9 |
;; be created per road patch. Set up the plots.( d. m0 V' P/ \5 E( t
to setup7 H1 R. A. a3 w' r# ]
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setup-globals
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, ^' f' u# S! }0 f: f# q& _( x$ { ;; First we ask the patches to draw themselves and set up a few variables
N( T8 W( y% b setup-patches6 T4 U( e8 C; L- ~' K
make-current one-of intersections6 _1 p! d& ~- B' P
label-current( U( x7 w3 `" U
- \' S0 A8 y% [6 X) V. Y1 q- B+ Y set-default-shape turtles "car"- z! G0 O- ?( x: a0 Z; ~
3 l' r }# N5 ? K7 L/ h' C+ d- e# ^( V2 w2 v if (num-cars > count roads)
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5 m4 b9 `- s, t& j5 K user-message (word "There are too many cars for the amount of "9 s6 [$ r3 {$ T3 P, z: P
"road. Either increase the amount of roads "% A, d; M5 H) ^$ m6 j7 x. B1 a1 U
"by increasing the GRID-SIZE-X or "
+ e/ W! Q9 @8 x/ h "GRID-SIZE-Y sliders, or decrease the ": l! G X" B X" _, k- c. G
"number of cars by lowering the NUMBER slider.\n"' T2 I0 u, n% z1 M) O
"The setup has stopped.")$ g7 d1 i/ p1 S+ D& m
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color" @" |. t" H) Z y7 ~
crt num-cars h' a0 x, |- l m7 x, k' P! W
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+ j2 O5 L/ F# x- J8 w7 m% u5 K setup-cars
2 i C% z# V' | set-car-color
2 h4 H1 S# O) m' M5 a# y I record-data
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' k" p& d1 A6 `$ E+ z' N4 C7 k9 _ ;; give the turtles an initial speed# B1 u3 S( k7 Q% r' Q
ask turtles [ set-car-speed ]" g0 |5 w0 ?, X' T) G9 M
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reset-ticks* E& D2 J- M: v. {
end
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6 a6 m8 [, y! `+ [" g9 F% A;; Initialize the global variables to appropriate values
, E1 B: E g: _+ }to setup-globals
* [; p5 l5 X) O. n; z1 Z N set current-light nobody ;; just for now, since there are no lights yet6 u$ a- D* h! `; Z1 t9 y; U
set phase 0! J0 C5 R4 i! Y2 T( n5 O
set num-cars-stopped 0
. F7 N% |/ f9 I# ?" J2 o4 H set grid-x-inc world-width / grid-size-x
9 Z5 h$ G! G2 B" H: p0 w, k set grid-y-inc world-height / grid-size-y& f9 ?- D- W/ u" i
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
( Z3 \/ l0 W0 }& ^ K- L set acceleration 0.099
- [. K8 e" b' J g1 [end
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6 t& Z9 w7 z1 u \( E( A3 G2 D;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
+ Z1 Y$ Y' d/ V- p! A) [4 ?;; and initialize the traffic lights to one setting: U% s1 y- O( w6 M3 S
to setup-patches
4 f" x/ J r P2 V, ?9 H ;; initialize the patch-owned variables and color the patches to a base-color* g5 J, [ K! x& |( @ E2 }; D( k
ask patches
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set intersection? false
* ]+ D+ Z# {+ Z) ~- F- c set auto? false4 Z8 @7 ^7 g- m; x3 J
set green-light-up? true$ @# O) w0 F( |# k) j
set my-row -1
. U) V" M/ I% y% h set my-column -14 G" A1 \" b4 V; i1 t6 N
set my-phase -1
6 m9 k% Y# G# v! m; D set pcolor brown + 3! L$ t8 }8 S9 x V5 M
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;; initialize the global variables that hold patch agentsets, m% Q( Y [9 I+ w6 ~$ ]
set roads patches with
9 Z. |- @4 `3 O/ {# o3 A: ? [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
3 r4 _( g; z2 b- U8 ` (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 h/ H1 d$ y7 e set intersections roads with# X/ _3 }; b. ~
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
6 Y( w8 |; i% _$ ?2 }) j" C1 R! ? (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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$ I; Z- i# p6 ]) B ask roads [ set pcolor white ]
4 L) p& _9 m8 P3 o- W. L5 N2 j3 w 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?$ ~3 G( I- T+ o% x2 P4 P5 E7 z5 M6 `
set roads patches with
' ~7 P7 e: X3 A [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
- X5 S0 x2 s0 D (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
! e) j- J2 j; G9 m# o0 L- d- V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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