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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。% Y( b. h, O. s7 ]
netlogo自带的social science--traffic grid这一例子当中,; Z/ l2 `; f# L9 H2 G
globals5 t: w9 n) J' c( v" I
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grid-x-inc ;; the amount of patches in between two roads in the x direction
% [4 t- N# `! |6 G* c0 V grid-y-inc ;; the amount of patches in between two roads in the y direction
. Y" X8 k6 u" T/ ^' D acceleration ;; the constant that controls how much a car speeds up or slows down by if
2 ]5 x% _; e* r7 f+ n ;; it is to accelerate or decelerate3 F" o, G4 O& _7 B7 a
phase ;; keeps track of the phase0 _4 Z4 ^: x6 M9 C; o
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
" h" o9 R( \5 ] current-light ;; the currently selected light2 E* V/ Z7 |2 f' t* y8 u
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;; patch agentsets8 W$ O: _1 V7 m! ~
intersections ;; agentset containing the patches that are intersections* x; g7 A( c+ g) z! s
roads ;; agentset containing the patches that are roads# R, G' H# Q* a
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turtles-own" h, M2 J7 C* b3 x. J! d3 H
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speed ;; the speed of the turtle6 T: [: j% s9 w- s& l
up-car? ;; true if the turtle moves downwards and false if it moves to the right- H* o1 g# _' ~; o! }
wait-time ;; the amount of time since the last time a turtle has moved
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# [' i9 T6 @: ]% u* N4 _0 hpatches-own
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intersection? ;; true if the patch is at the intersection of two roads* \& t1 ?. g$ U2 ]6 z" j
green-light-up? ;; true if the green light is above the intersection. otherwise, false.$ E" t# F& d, O* m
;; false for a non-intersection patches.
/ z4 a# k) M: r3 y4 B" S9 X \1 r my-row ;; the row of the intersection counting from the upper left corner of the
0 i1 d% f5 m8 n% Y1 V- B/ Q6 n ;; world. -1 for non-intersection patches.
+ O; E+ m% Y1 u% y ]/ ~3 C% A4 k my-column ;; the column of the intersection counting from the upper left corner of the3 D: w0 m5 Q. A# j s4 t2 L
;; world. -1 for non-intersection patches.
8 d; H* [# |, e6 Z% j5 R \ my-phase ;; the phase for the intersection. -1 for non-intersection patches.2 M( d$ z) {& x
auto? ;; whether or not this intersection will switch automatically.5 T i: C$ E6 C' J) C
;; false for non-intersection patches.
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% o; |2 z/ u y; b* O;;;;;;;;;;;;;;;;;;;;;;- ?7 S& \# E) B# ~
;; Setup Procedures ;;
2 ^5 S( h3 t" e2 {) _% `' I;;;;;;;;;;;;;;;;;;;;;;. }3 U5 {. T' u8 M
7 c0 U0 Z9 c4 R" S, @+ D;; Initialize the display by giving the global and patch variables initial values.
5 [( q5 ]1 b, r3 h" p;; Create num-cars of turtles if there are enough road patches for one turtle to( _' V; j p5 G2 v& _
;; be created per road patch. Set up the plots.+ P0 s7 v' `8 E
to setup
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1 L8 N" W+ Y9 {# n; p setup-globals5 Y2 ~; }; A5 e2 D
+ K- K8 J) @) q& k5 b% X. I ;; First we ask the patches to draw themselves and set up a few variables
1 A! [- P# Y- n" t3 [ Z setup-patches0 S) I4 _- ?% A6 H8 j
make-current one-of intersections
4 @ J/ f+ F6 \$ z: a1 N5 ^ label-current
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1 `6 a2 u* W; s0 X; P* x set-default-shape turtles "car"
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! C5 p/ R4 B6 k, I6 k6 t if (num-cars > count roads)( U7 H' t! L; w6 _7 A4 n4 P9 e
[
: `: `( Y. {" N) F m user-message (word "There are too many cars for the amount of "
9 @7 N0 C L. E# [& | "road. Either increase the amount of roads ": ~1 {, H) a" A4 H) V/ k6 O$ L
"by increasing the GRID-SIZE-X or "+ Y/ L* V9 M. C5 X
"GRID-SIZE-Y sliders, or decrease the "
7 e4 l) ^2 L: n" j7 J "number of cars by lowering the NUMBER slider.\n"' j! R: b3 I; ^* r
"The setup has stopped.")
$ _9 Z3 `7 o6 a9 m$ \ o& u9 S) g; d stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
3 d2 c: N9 l' a' e; ~1 h crt num-cars
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setup-cars" M$ B* ~! u$ b9 C$ C
set-car-color
9 A9 G8 ^9 k; p# h2 Y. M record-data2 T/ E3 T- a& l& }% W4 X
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' ^; j9 T/ Q" C2 P3 _ ;; give the turtles an initial speed
6 m, ~ W9 p% Y6 G0 l ask turtles [ set-car-speed ]
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1 V: D; L0 A; L reset-ticks5 V. u- @% u R
end) P8 r |) a7 h3 V+ D. ~
3 B( U* t3 g4 `' }0 P) U8 W;; Initialize the global variables to appropriate values9 C0 Q7 B1 G. O* h W2 {
to setup-globals& U, ?8 x5 A- I
set current-light nobody ;; just for now, since there are no lights yet
! b C: t5 o8 k8 ` set phase 0
- Y% t7 C2 b4 F+ J set num-cars-stopped 0
0 ^( ~( D6 E" S& Y" O' b& g* H set grid-x-inc world-width / grid-size-x
# [" ?* e5 o" ? set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
. X1 F. c5 A$ a, o) C# p set acceleration 0.099
: K% q, c% ~5 L `% i' gend
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: {: \0 e2 }) T5 b. ?" m' j) ~;; Make the patches have appropriate colors, set up the roads and intersections agentsets,, |7 _1 B$ J# F$ @
;; and initialize the traffic lights to one setting* x' f) Y# F( H5 n( i
to setup-patches1 N2 F! @' n8 u/ z+ r
;; initialize the patch-owned variables and color the patches to a base-color
) k5 L$ H& d' ` w" u ask patches
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2 t4 A1 p$ V' J7 |( x; r set intersection? false
& a! X# W) n$ z, s4 k3 d set auto? false
# V0 m% ^( o; e! F, c0 q0 R5 { set green-light-up? true; J H8 f! O8 h4 v
set my-row -15 N5 q* u! q9 Y" w) Q# b, E
set my-column -1
, ~1 D6 L5 O5 V5 `, R) ?1 H set my-phase -1$ P0 C- D" P& S; T
set pcolor brown + 3/ M1 K8 l' B8 h8 j. }8 J8 w7 ^
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;; initialize the global variables that hold patch agentsets
2 g* I& H2 o& \ set roads patches with2 A* X% D9 }( a7 G; T8 r. d: {
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
+ Z$ g, u8 G3 w( H; h (floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ q: B# {) w$ C
set intersections roads with4 b6 C- \8 T+ U7 i
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
4 W% B8 @# V( w0 n4 S (floor((pycor + max-pycor) mod grid-y-inc) = 0)]; _" d: j! b; ]# @9 m
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ask roads [ set pcolor white ]
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其中定义道路的句子,如下所示,是什么意思啊?0 T( `" [* T( m) ]" ]$ z! c! E
set roads patches with. @1 M% ~0 O8 Z' X* K
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or! K/ B5 s+ u, M( }
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 h% w7 Z8 i- m0 T+ ^7 _, @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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