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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。5 [: c o8 j) j9 g
netlogo自带的social science--traffic grid这一例子当中,
. ~- t* D' h" B2 a- C, ~. ~9 hglobals1 l7 X: y* I" [8 ~* |' h/ V
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grid-x-inc ;; the amount of patches in between two roads in the x direction6 F; E" V F& G N
grid-y-inc ;; the amount of patches in between two roads in the y direction
, Q' m, t2 P- c2 J! X acceleration ;; the constant that controls how much a car speeds up or slows down by if
% E! ~$ F1 E3 ?8 z. U$ k ;; it is to accelerate or decelerate- q' m3 p) k% x a9 ~/ a4 Q9 c
phase ;; keeps track of the phase
1 L# Q0 k( j5 n: k6 g num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure! t/ p7 ]) D( C+ a
current-light ;; the currently selected light
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" s9 k5 Y8 ^6 | C ;; patch agentsets6 n+ R9 Q: `& r8 Q
intersections ;; agentset containing the patches that are intersections
- F0 {2 T9 R. I; x: m4 T roads ;; agentset containing the patches that are roads F# X- f8 O( a5 T2 q+ x h
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9 e9 E+ p8 u7 pturtles-own7 |9 H0 Z T, N' @$ T1 N
[
, g; E5 A' _2 i) r S& [ speed ;; the speed of the turtle; \& s5 P5 Y* Z+ \* _
up-car? ;; true if the turtle moves downwards and false if it moves to the right9 y/ f3 h- F5 U
wait-time ;; the amount of time since the last time a turtle has moved
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! n* u5 |4 E6 A, Z8 Z* p! vpatches-own
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intersection? ;; true if the patch is at the intersection of two roads. L1 r7 E/ f: s7 M4 ^
green-light-up? ;; true if the green light is above the intersection. otherwise, false.7 _) k% I; b1 X
;; false for a non-intersection patches.
' X1 C) }8 b: L ` my-row ;; the row of the intersection counting from the upper left corner of the
' q) X, L. F( j+ ~, o ;; world. -1 for non-intersection patches.
8 w! G5 a8 N3 b' f6 G my-column ;; the column of the intersection counting from the upper left corner of the
0 |7 A! q# V* j+ h( Y' B ;; world. -1 for non-intersection patches.
' G% _ e9 `: d( j+ u+ S my-phase ;; the phase for the intersection. -1 for non-intersection patches.. B0 M* A2 S$ Q* W% [9 T
auto? ;; whether or not this intersection will switch automatically.9 T+ T! [' {" _' O
;; false for non-intersection patches.
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5 z* ^7 s2 A0 ] h; V( G* Z. P;;;;;;;;;;;;;;;;;;;;;;1 ]- Y3 ]3 ^ u$ h
;; Setup Procedures ;;
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! h& z8 ]3 y3 p;; Initialize the display by giving the global and patch variables initial values.
' ?4 \* p0 y, n( m5 ~/ B K Z+ y;; Create num-cars of turtles if there are enough road patches for one turtle to" y6 g) z' u6 T
;; be created per road patch. Set up the plots.& a. M( ^- S! Z8 M
to setup6 i) P5 u- z. y3 e5 J% z4 H' s% ?
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setup-globals; M. u _& p v2 Z, Z
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;; First we ask the patches to draw themselves and set up a few variables6 i* |3 T2 A! Q
setup-patches) d7 |) j$ H1 L6 b. P/ ~9 q5 H
make-current one-of intersections. R7 x. C. F1 G1 P( x: E: l* Z* o
label-current2 s2 c8 A, H' P) E% G5 `( t
- Z( X% G+ w$ i k @& B8 ? set-default-shape turtles "car"
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/ ^! L4 q; l6 ]. o. l( J* t if (num-cars > count roads)2 ^( ~4 N5 G' ]& f. y5 M4 M
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user-message (word "There are too many cars for the amount of "
; X) w2 G2 G' U "road. Either increase the amount of roads "
4 y. G" Q4 |4 g5 @/ ? "by increasing the GRID-SIZE-X or "
# f# ^1 L; o6 L- a6 {- { "GRID-SIZE-Y sliders, or decrease the "
- D8 p, I, h3 f: f "number of cars by lowering the NUMBER slider.\n"
# k8 P7 q) }* l7 G "The setup has stopped.")6 [* s' P4 f. X% }; }4 k/ ~
stop
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6 ]) P9 r( D- r5 K( y! p, w3 Y ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color' U$ @6 Y' a; C4 T( d6 H
crt num-cars
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setup-cars, Q# r+ Y2 o* v( A7 C: t
set-car-color
( j9 F' [5 @5 ^ record-data- h$ Q% A4 F2 a& m" ~
]
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$ A! Z# P) u8 i5 a: c( N ;; give the turtles an initial speed
R+ I# t: s) z" y' @- T ask turtles [ set-car-speed ]
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; s! E" ^* { G, ~ reset-ticks
( z2 f3 I2 M7 iend
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;; Initialize the global variables to appropriate values, c4 v B$ k* F, }% w
to setup-globals
) E; g8 {% x% B* t5 h set current-light nobody ;; just for now, since there are no lights yet
! Z5 ?9 h. T5 ]& X) E set phase 0
3 L8 _+ Y$ n% z2 L set num-cars-stopped 0 }& Y& ]* u7 x9 m
set grid-x-inc world-width / grid-size-x
; a; H! Y: M" G( O9 ?! a set grid-y-inc world-height / grid-size-y& f% r9 F3 Z1 }6 Q
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
7 R, g( u/ o) X$ L. I% Y. k set acceleration 0.099+ b& K; q: B7 R0 |. d# s1 ]
end# d9 X- E/ P+ @9 X# n. p
+ s* N& M6 ~& c, d6 ?6 W) u;; Make the patches have appropriate colors, set up the roads and intersections agentsets,9 u" o0 D+ t9 J* L% w5 k9 r
;; and initialize the traffic lights to one setting {6 o5 J. w* P7 Z. i( B0 N
to setup-patches3 e, [% _ H! x/ F* F( @
;; initialize the patch-owned variables and color the patches to a base-color% i# d0 `" b$ h) o: W; N4 [
ask patches$ N) b9 U( B5 D% ?- I
[
; X5 t9 E; o3 ]0 Q set intersection? false
4 X2 `5 V) t) b2 K3 z; a5 D set auto? false4 G9 Y. Y$ W h; h* ?5 G
set green-light-up? true {9 O1 y9 I) X/ _
set my-row -1
$ Z( Y6 x* G* n7 |: m set my-column -10 ]! z5 | O( r ~! f8 Y
set my-phase -1
9 u6 I5 d6 P8 U( E; I2 w9 q/ I' ~ set pcolor brown + 39 x+ q1 z- j9 z& p3 ]
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;; initialize the global variables that hold patch agentsets
U- b, J6 U& I, w set roads patches with3 b+ L8 r8 H5 [# ]6 t
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: m2 d3 Q2 D( ]% f2 m% _+ F; A* v (floor((pycor + max-pycor) mod grid-y-inc) = 0)]: I2 \1 q* H3 f7 v
set intersections roads with* E. l& \: K8 Y8 G, i1 j( i" D
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and* h1 G9 v/ y( v5 i; U1 X
(floor((pycor + max-pycor) mod grid-y-inc) = 0)], ?5 `0 M5 T6 [2 N1 Z, Z5 @( H& n0 r
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ask roads [ set pcolor white ]
5 F4 \$ U4 H0 `. r2 Z* C' g; N/ m 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?
7 D& @# c* l U+ m4 ]& f set roads patches with
" N+ x1 i+ `% l. M. k W. n9 u- _ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# k' q% M' `) O (floor((pycor + max-pycor) mod grid-y-inc) = 0)]( Y+ h5 _1 }8 e& `6 s) d; _
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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