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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。% z$ K* u1 a9 t+ G+ a E( ?
netlogo自带的social science--traffic grid这一例子当中,
- S. h$ n; c( x+ yglobals+ L! ?1 Z% F+ c% u
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3 B7 Q0 b4 ]0 s grid-x-inc ;; the amount of patches in between two roads in the x direction6 Q& U+ u4 i( x: `
grid-y-inc ;; the amount of patches in between two roads in the y direction3 f4 T; F# D$ f b! H; u
acceleration ;; the constant that controls how much a car speeds up or slows down by if
0 X5 l; s3 ` B4 J7 I" C ;; it is to accelerate or decelerate
' Q" f; W a5 Y phase ;; keeps track of the phase
. q1 s O5 ?# _, ]$ A num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure0 I- T& Z0 W- G2 }0 e( d
current-light ;; the currently selected light
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9 G. a% l" M( i6 {+ U1 g# Q; F7 z) B ;; patch agentsets
; z- W, f8 C4 w' M6 w: n6 X( N intersections ;; agentset containing the patches that are intersections9 y9 Y! ]$ A0 E/ O& k% L) {1 ^: B
roads ;; agentset containing the patches that are roads
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. H6 v% H% F: n8 ?. oturtles-own
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2 m+ s, d( J. {! g speed ;; the speed of the turtle
( r# J, z* a& b2 I* b: x, ^ up-car? ;; true if the turtle moves downwards and false if it moves to the right8 N7 H0 ~8 p, n" X
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own% |6 X; t7 r% b# O) l
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1 R! ^- g2 j1 _+ N% Y intersection? ;; true if the patch is at the intersection of two roads
8 Q4 [: [$ m1 Q) E# H5 p, p% Z green-light-up? ;; true if the green light is above the intersection. otherwise, false.
2 k) W, D) T5 |1 Y5 q4 \ I; f ;; false for a non-intersection patches.
- E; b7 |: W9 x my-row ;; the row of the intersection counting from the upper left corner of the1 j7 U+ V8 k- ~& \# H; f" j! q
;; world. -1 for non-intersection patches. |6 I% y' ]7 u( Y$ ?5 O
my-column ;; the column of the intersection counting from the upper left corner of the
) F% k* x* e+ k6 Y; ~" E% `5 E ;; world. -1 for non-intersection patches.
% G7 U2 o) A3 ?7 | my-phase ;; the phase for the intersection. -1 for non-intersection patches.$ g4 `' `$ K! M6 y
auto? ;; whether or not this intersection will switch automatically.
( z5 u8 P5 J5 i ;; false for non-intersection patches.9 R @ j& u6 t9 d! }
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;;;;;;;;;;;;;;;;;;;;;;) T: `9 E! k1 w. m
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.1 G2 Y4 v! a/ _# y
;; Create num-cars of turtles if there are enough road patches for one turtle to
0 ]- E$ N$ A& C, G5 H" N& i) _" A8 ^;; be created per road patch. Set up the plots.0 o* P6 H1 t2 ^
to setup: s# C& o7 g5 R6 Q) \
ca
' V4 _6 R% q' y setup-globals9 D$ T) u# z, S
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;; First we ask the patches to draw themselves and set up a few variables
3 ~5 ]2 G0 c5 q; z. D setup-patches! `! D, ~( K6 M0 m
make-current one-of intersections
1 z0 E5 a" X. H: f+ @ label-current7 \3 `8 I. L" H" n3 r8 i. ]" l5 F
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set-default-shape turtles "car"! H6 S) `1 c4 p/ \ W
# j$ H: w, F* X9 M$ W if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "7 t; Y7 i% ?+ K$ v$ q6 d& ]
"road. Either increase the amount of roads "
0 H, m) a R7 z! ^3 \) @8 V) E "by increasing the GRID-SIZE-X or "' [5 w$ M+ R: T$ q
"GRID-SIZE-Y sliders, or decrease the "$ }' b9 p* e# m
"number of cars by lowering the NUMBER slider.\n"
0 J& B4 Y( {4 f# J" T "The setup has stopped.")
& R- Z& X6 Q7 y& z" } stop# G: n; l( ]! K& u! M: v! P, K4 ~
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color* V5 I% u$ {0 W+ L3 G/ K
crt num-cars
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setup-cars( R2 a+ Q1 Q3 @1 a. d0 H; [
set-car-color# Y: T7 J( d* S+ G2 p" ]
record-data
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$ W0 Z6 o& T& T, n8 } ;; give the turtles an initial speed7 M7 C9 E! H/ p/ k8 d" A9 U
ask turtles [ set-car-speed ]
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reset-ticks
% B# ]# N7 }3 X: Send
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;; Initialize the global variables to appropriate values
9 `+ L' n& u4 n0 ~to setup-globals
; h% j1 \6 D1 @( a# w* n set current-light nobody ;; just for now, since there are no lights yet& Y% s( |% Z W1 e
set phase 0
! W5 a, b1 a7 Z9 o* x- Y" k- L set num-cars-stopped 0
0 b1 s" K' G6 y set grid-x-inc world-width / grid-size-x v4 @) ~* w3 m3 _; U, [7 V
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
2 N: t S( t( r0 P- N/ R set acceleration 0.099! R9 P( L' S7 W( i6 P" D4 l$ T
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,+ R1 ~* L3 u( X& i
;; and initialize the traffic lights to one setting j f% E1 U$ `8 x2 O! t5 T$ K9 t
to setup-patches
; h1 P: ~- @! O [% A4 ^ ;; initialize the patch-owned variables and color the patches to a base-color, y+ X; ^- V& \) p/ v
ask patches& w! h$ E- u0 w8 F8 ?9 O3 z$ C' r
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) n. U& K2 y- @! n' ` set intersection? false/ Q# i5 _. f1 s r6 ?' m2 q
set auto? false
6 v* E E+ F' P W6 m) A( R set green-light-up? true
' F7 u# p+ W. j$ p! X5 [ N- L set my-row -1$ p6 g4 h+ _& L& c6 m ?9 F B5 Q" ~
set my-column -1+ K- d+ [5 @' @
set my-phase -1& N+ f. x" ~ k* L. n
set pcolor brown + 3
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2 h( ]! s( { D* Z; e ;; initialize the global variables that hold patch agentsets# q1 H5 ~+ k. A1 m0 l5 g+ |
set roads patches with
7 q3 W: e4 t: m6 q0 h. x' I D [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or( J, D% F) F! z/ F
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
! c; Y: Y# M# _ set intersections roads with
) v0 `. I! o& L; ~+ P [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and3 S8 H9 A& F, z/ U
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]- W6 Y4 n2 K+ S7 }0 \( @
5 Y6 j) ]* h( Y$ V" v ask roads [ set pcolor white ]) R' M# L1 F5 r) h2 B
setup-intersections
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3 F [. }3 H; R0 s6 y其中定义道路的句子,如下所示,是什么意思啊?
; C/ S" O2 c: e/ p4 v5 H set roads patches with1 j" R g0 |* h( ]& g$ P6 z, z6 m _) d
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or: P3 W' s- \) t) K
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
5 d% j) _! e7 @/ U+ m- ?3 g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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