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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 N3 H) o9 }2 r m# H% d1 gnetlogo自带的social science--traffic grid这一例子当中,
% `9 }3 K( O. `$ G4 Qglobals
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2 @* X' B4 B5 m: R4 y- W9 ` grid-x-inc ;; the amount of patches in between two roads in the x direction
8 }0 i: ]0 \2 C: m, y- ` grid-y-inc ;; the amount of patches in between two roads in the y direction% g; ]% R3 _5 K6 f) L
acceleration ;; the constant that controls how much a car speeds up or slows down by if
/ E! r# z: r7 `$ J! }+ _ ;; it is to accelerate or decelerate- Y4 @: a$ C, q; h9 W9 G; I
phase ;; keeps track of the phase% C! g$ h# P+ k+ x2 ]* C+ X G
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure B/ j9 V2 _9 z* @
current-light ;; the currently selected light
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5 q9 F& t9 g1 ~, l ;; patch agentsets
' @, O9 h0 O: R2 M2 A9 e: m# R; a intersections ;; agentset containing the patches that are intersections/ v) p+ n8 n3 g3 Q# @ v l" P5 Y; O
roads ;; agentset containing the patches that are roads$ Q0 s, S& n. t; B
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turtles-own
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speed ;; the speed of the turtle
$ O$ K. k" O7 R4 g, [1 j! P9 A1 D( M up-car? ;; true if the turtle moves downwards and false if it moves to the right
/ n, P0 D$ v5 R wait-time ;; the amount of time since the last time a turtle has moved# i2 j/ _( U# P Z( @
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
# ^7 k& E# f, r& f* j+ G4 V/ i green-light-up? ;; true if the green light is above the intersection. otherwise, false.! Z, W% p4 n, S$ g/ q% p* R2 j
;; false for a non-intersection patches.
+ k& C# V$ i8 X: V my-row ;; the row of the intersection counting from the upper left corner of the+ |$ `5 v+ T7 g- s9 z
;; world. -1 for non-intersection patches.
1 @9 h2 H9 w( Z4 g my-column ;; the column of the intersection counting from the upper left corner of the3 {) F# s+ s* b3 `
;; world. -1 for non-intersection patches.
5 D. s9 n$ v* Z) ] my-phase ;; the phase for the intersection. -1 for non-intersection patches.
% _% K& b# g% [. y auto? ;; whether or not this intersection will switch automatically.
* ~2 Y' I0 k6 G3 N ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;" Y+ S& f- v m1 M w/ O
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
+ x& C% P/ H- F1 g;; Create num-cars of turtles if there are enough road patches for one turtle to! d- z2 h+ H( O3 J3 j5 @
;; be created per road patch. Set up the plots.
! B: |) f" ^2 h- P" [to setup
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8 q/ v) D2 [+ v0 U# g9 S1 E" R setup-globals0 E: J" J- Z& N! H
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;; First we ask the patches to draw themselves and set up a few variables+ |# v. l& L, {, K
setup-patches t7 u( V/ w% \- E& r) Q
make-current one-of intersections. J3 w2 r! D. Y
label-current
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! V4 C' t5 R( v& t |+ }& x set-default-shape turtles "car"
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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 "8 o. _* H% a, l6 e
"road. Either increase the amount of roads "
) v" L; p. t9 m! ~5 S) ]* g' t "by increasing the GRID-SIZE-X or "
: t2 l( z, D# Q6 ^/ X! n+ D "GRID-SIZE-Y sliders, or decrease the "
: g( q" w* I) [ N "number of cars by lowering the NUMBER slider.\n"+ w% E7 o+ t; X8 B0 i/ D9 x S, W
"The setup has stopped.")/ h/ K2 N& Z% V! R% _* x( m4 b6 ^
stop# q: V1 E" H7 c4 R
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' E0 B0 S! I( x @: W/ ?2 I* E4 d ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
- L$ ^. O1 V4 _. W& q2 M crt num-cars% f( u+ F* q9 I0 m$ [% D
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0 X7 p, m/ d, v1 i7 J% K2 @ setup-cars
$ e! K+ g3 D. v set-car-color
: F) x7 U( R" Q0 ]+ Q: R record-data
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! Z/ X4 M6 w$ j: ^2 G9 F1 I( ^ ;; give the turtles an initial speed
+ e# O. q) w) C7 R ask turtles [ set-car-speed ]! I5 Y% l- W6 H7 \- o" l- f7 H7 Q
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reset-ticks
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+ v1 V3 `2 ] i% @+ S;; Initialize the global variables to appropriate values5 S, i' y* G% ^6 ?1 L
to setup-globals
1 T/ a# i9 Y3 P8 e set current-light nobody ;; just for now, since there are no lights yet
4 v* b3 k1 ?+ b/ Q, @- ?% M0 l `! s p1 p set phase 0/ b9 r8 c$ ^: d+ _
set num-cars-stopped 01 a: r1 _% B5 h2 R' j V$ f! w
set grid-x-inc world-width / grid-size-x1 |) o3 G. O6 U. x x, 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
4 f. H, J1 U( k2 D' T set acceleration 0.099( V% l" n) L' V% X
end
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$ g/ O# \ I" l6 z;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
; U9 G1 u2 A0 A5 x5 ]8 d; i- I;; and initialize the traffic lights to one setting
8 Y) |+ ^. u0 Q0 t( zto setup-patches( B5 [, x1 N, t: O! ?: `
;; initialize the patch-owned variables and color the patches to a base-color
' n" A( ]3 W& y/ V ask patches- X7 \/ j6 R9 |- S6 c; |
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+ J/ X4 u( `" h" r$ E3 F set intersection? false: p% e [5 c. s
set auto? false; ^3 D a9 Z; H4 G- p0 S
set green-light-up? true
+ n! D7 ]2 Q* J+ y" l set my-row -15 C$ T( ^5 H& H& y% \
set my-column -1
3 d* x( I0 V: \! G8 u' s5 Z$ |( i set my-phase -19 R+ ~* g* C1 e5 f
set pcolor brown + 34 h/ U. P6 y+ v9 _- H% B
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7 y7 J3 v& u8 T; I' n ;; initialize the global variables that hold patch agentsets5 Q1 A1 `) `& h' C, g
set roads patches with
3 Q5 d$ B4 }; d1 u |" W [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or( N5 V# x4 ^+ s j8 c: w* V7 X
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]. s; [4 V7 k( K v$ I
set intersections roads with
1 I! T& G. `. C$ c [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
# V6 g/ n. P/ G' L" `. W5 u E (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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9 j; {5 H) M$ Z+ {2 u% G) r, m ask roads [ set pcolor white ]
2 v' q' N& F! f1 u setup-intersections" N9 ]9 T) N9 G- O5 h
end( e+ T- c$ p2 T3 Q
其中定义道路的句子,如下所示,是什么意思啊?
" \8 I. ~* m4 T- e& N/ M1 E set roads patches with3 l) g6 @& k1 w* Y' Y9 p1 \5 G/ M
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or5 M9 g) N7 } ]
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
# ~0 {. `% P7 l& a7 i. A4 o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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