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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。
7 p" J L. F! ?' i0 ]6 {" K4 q2 Fnetlogo自带的social science--traffic grid这一例子当中,
7 B# t: o) d) o& C& ?6 ~globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
# c0 ]4 }) v( W0 K- M9 O grid-y-inc ;; the amount of patches in between two roads in the y direction
( v2 L0 [7 O7 N( h+ m) l4 B6 x acceleration ;; the constant that controls how much a car speeds up or slows down by if
' ~+ V( |0 F9 B. ]8 d n, L6 f ;; it is to accelerate or decelerate4 y. A9 [; e! X; [9 T
phase ;; keeps track of the phase& o5 h0 C4 U9 M: M" }( X$ d5 H4 }
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure( S6 p6 \4 d0 H7 z! g8 U
current-light ;; the currently selected light( k* h, c: A3 m% |. Q. v" ~1 O
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;; patch agentsets
" @! k* r( K5 V0 h# a8 r' i intersections ;; agentset containing the patches that are intersections" i% v! p4 U0 k, u& R9 A+ j
roads ;; agentset containing the patches that are roads& J/ o5 a8 h. o0 _
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0 a1 K' K3 g0 B* @; d6 G' Wturtles-own
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speed ;; the speed of the turtle' G) J7 y6 e% }$ F
up-car? ;; true if the turtle moves downwards and false if it moves to the right
! n( `8 y' z" Y wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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% K. ~" j& E: k8 z& v8 [ intersection? ;; true if the patch is at the intersection of two roads% m2 |1 h5 M3 S" I/ q- p, G
green-light-up? ;; true if the green light is above the intersection. otherwise, false.& B8 I5 L9 J! h9 u
;; false for a non-intersection patches.- T6 `# v! c1 B0 o6 f4 N! ^
my-row ;; the row of the intersection counting from the upper left corner of the. s* |3 q$ R9 M7 `
;; world. -1 for non-intersection patches.! `) k, F, n7 x5 M$ g- B4 B- i
my-column ;; the column of the intersection counting from the upper left corner of the
# L2 [- e- H3 Y, T C ;; world. -1 for non-intersection patches.$ t; O3 d! Q+ }0 P, Z0 D$ `
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
7 I+ y [' C5 {! u3 N) d" c auto? ;; whether or not this intersection will switch automatically.
/ w% V8 K# e$ f ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;6 N, i$ j( @9 f/ |
;; Setup Procedures ;;$ r3 J- i' \" t
;;;;;;;;;;;;;;;;;;;;;;
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2 a" l* A# q! y# I" r;; Initialize the display by giving the global and patch variables initial values.
3 G5 x Q: J* X q0 L* L- [;; Create num-cars of turtles if there are enough road patches for one turtle to1 N% u9 u) p5 d3 G; X/ ^
;; be created per road patch. Set up the plots.
' o& E5 Y* r9 d5 i+ Vto setup
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setup-globals
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4 e6 C5 t! |4 J9 Z) I! ? ;; First we ask the patches to draw themselves and set up a few variables
" D9 g2 u& L7 R) h, ?* u setup-patches% O$ H1 p' U! t/ s
make-current one-of intersections" u* {8 x- t1 S8 u
label-current
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set-default-shape turtles "car". O8 v9 }* \$ ^7 ]1 U
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if (num-cars > count roads), y5 Y, `% B6 q9 ^: k2 `
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) g0 }! A0 [3 a user-message (word "There are too many cars for the amount of ") F* n; g9 a$ y: L3 K! D
"road. Either increase the amount of roads "8 R, h. @. _' t- ~8 J) |
"by increasing the GRID-SIZE-X or "
% L) Q9 N) q* ]3 Q9 e$ a1 V "GRID-SIZE-Y sliders, or decrease the ", M6 C/ ?5 G" [
"number of cars by lowering the NUMBER slider.\n"
+ i* S, M. Z; X* F4 n- D! ^: C "The setup has stopped.")
. S! I( V, N$ U stop
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1 I0 }1 ^" [% V4 e9 o- M ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color) a. W& @4 Y# K/ K+ p
crt num-cars' A# W; I; k( K% G
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setup-cars. R7 l* K) \* Q+ S) d# W: M
set-car-color
- y1 N G. k9 D7 Z( j* N5 K& s record-data
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;; give the turtles an initial speed! T. f. K+ {8 q! R
ask turtles [ set-car-speed ]
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reset-ticks3 G! D# p1 } l0 G2 m* _0 |
end3 j ]+ T* z g* v1 Z( s5 ]5 T% Q
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;; Initialize the global variables to appropriate values
/ a4 X) f* t/ r5 c9 Vto setup-globals
, W" v; I8 ?8 P; ?9 x0 } f set current-light nobody ;; just for now, since there are no lights yet
' I% n3 R* u, p6 R3 q. X4 x set phase 0
9 X. `' X( b" E1 B8 s; Y8 z2 I8 P set num-cars-stopped 0; ^9 f, I/ [3 @+ \2 N* V3 \! f1 Q
set grid-x-inc world-width / grid-size-x
& i) G2 T9 B' }# ]7 Q) ^ set grid-y-inc world-height / grid-size-y( }1 E5 B4 i* c5 M, H: L
2 Q0 Q% K. Q& S$ I ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary6 G0 j, `% Q4 R! N- @
set acceleration 0.099 L( T3 |7 h, P9 q9 d, b
end, Z n0 t: l3 O# F) L, h5 a! N
; g* z) {# W9 N g;; Make the patches have appropriate colors, set up the roads and intersections agentsets,8 |! j. R k% X4 n) Y$ ?, @/ m$ v
;; and initialize the traffic lights to one setting
; W5 M3 e7 Z0 l4 Y9 Nto setup-patches6 {+ _- \2 ^/ [9 n
;; initialize the patch-owned variables and color the patches to a base-color
5 i$ ^ G R4 a* A ask patches% a$ n4 C s8 j
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M# \2 q* {! K( W- c$ x# V set intersection? false
% r0 h8 f# K0 h4 `$ u! H! ^ set auto? false+ P) q0 C d" c. k- {& O
set green-light-up? true3 V! P' E( b- `
set my-row -14 z5 H. L/ i% Y8 p. v9 e
set my-column -1) [# w) K$ N4 }* T. }/ ?7 D
set my-phase -1- {! u- W1 m' d. t9 e
set pcolor brown + 3
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& G4 { H; z- s4 x' E4 L% t% S ;; initialize the global variables that hold patch agentsets
! E. s( U2 I6 u5 Z/ O# b: O$ Z set roads patches with
; F" i0 p& j) ]# V6 J; k: T1 O: K [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 I+ E% k3 H6 d$ u u) e! K! } (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. A8 e6 D: O/ _1 g/ W3 p e set intersections roads with7 k4 ]( F4 q& V8 o- `6 U- M4 ~
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and3 B! o2 G, U- [
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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: l5 f' U- }2 ~; j* Z ask roads [ set pcolor white ]
$ ] D* @: d- w5 N- }; h setup-intersections( a1 x7 N; Q' Q, ?' K9 \ |
end
! J4 h5 r. E+ j: A7 A- v其中定义道路的句子,如下所示,是什么意思啊?) Z6 ]7 ?& H6 X
set roads patches with
( y5 f" n7 ~% @2 l+ f, ^: J |# h+ ~ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% b3 i: c0 N7 u! U' o& i
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
" y- \7 o1 h' }! ^/ 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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