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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。
( u) T) E" x3 C7 P( Unetlogo自带的social science--traffic grid这一例子当中,
& g2 w! c- W% N1 C% {globals9 C. D4 [9 p" X9 t. `
[
, n4 S3 q9 I* ~6 ~* h grid-x-inc ;; the amount of patches in between two roads in the x direction4 P2 u. o% A5 A+ Y
grid-y-inc ;; the amount of patches in between two roads in the y direction0 N& y6 F: H2 p3 o/ {$ o, d3 y h2 Q3 M
acceleration ;; the constant that controls how much a car speeds up or slows down by if
0 x7 `; E0 n7 f ;; it is to accelerate or decelerate4 |1 n7 X+ a! [+ Q2 o
phase ;; keeps track of the phase
( G+ s3 V$ ?1 {+ [: Z) P4 X num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure9 x. j a4 C+ }; J e
current-light ;; the currently selected light; I1 l: Y! x2 g% |& Y z
[+ J( `8 N+ y ;; patch agentsets
# _4 f5 f: j8 [# I- b intersections ;; agentset containing the patches that are intersections
/ ~6 x! P) A7 H6 d roads ;; agentset containing the patches that are roads% M" p6 I" G$ @" N
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turtles-own
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speed ;; the speed of the turtle
7 t( ~, B1 E( e1 E4 W; [( d% j up-car? ;; true if the turtle moves downwards and false if it moves to the right
6 m0 h- ]6 I' S% y* ]! X w( V wait-time ;; the amount of time since the last time a turtle has moved
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& Z# u6 e. Q' O: h5 ]patches-own- K, l! R7 v; b% v7 }, u
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) `% ^- r: A* J4 u9 U intersection? ;; true if the patch is at the intersection of two roads
+ o2 V& r1 U' E2 g' h% x green-light-up? ;; true if the green light is above the intersection. otherwise, false.
* V0 W6 e) H: r n ;; false for a non-intersection patches.
( F* M1 R: g, B n7 W' G my-row ;; the row of the intersection counting from the upper left corner of the6 b% a* r5 Q7 G2 U
;; world. -1 for non-intersection patches.
, n( x- I) Y; l, Z! ^ my-column ;; the column of the intersection counting from the upper left corner of the- b' e& C' E1 N- r* c, g$ U. X7 m
;; world. -1 for non-intersection patches.0 m" y3 ?$ L7 a) i S6 ^9 U
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
5 }9 | U/ n) ^. z) a$ F$ d N3 k auto? ;; whether or not this intersection will switch automatically.. P' N1 q v* D! c
;; false for non-intersection patches.
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9 n, l) x/ j0 | p/ o;;;;;;;;;;;;;;;;;;;;;;% m% K2 s3 x( a5 ?! p& g
;; Setup Procedures ;;3 p/ H& g& @/ l
;;;;;;;;;;;;;;;;;;;;;;
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5 T, v) a# a; B' ^2 |9 y0 D;; Initialize the display by giving the global and patch variables initial values.! s. Z& C" v* r' X( L# l6 G
;; Create num-cars of turtles if there are enough road patches for one turtle to4 m. p, e" I3 x) n5 q3 r& u
;; be created per road patch. Set up the plots.
9 g( T. K' k }2 Mto setup1 u- G1 Y& y& R; f& {, y) }$ z# R7 M
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setup-globals
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0 |; e) A, a3 r& W3 d# I ;; First we ask the patches to draw themselves and set up a few variables& q8 P, }0 m% W" s8 T. v
setup-patches
" s" L- x& b/ [1 `' I- F make-current one-of intersections
( D% N% l" J: m4 b label-current
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' ^& s3 E: n: o! G" o set-default-shape turtles "car"" j3 c o+ e C$ w
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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 "& T+ F2 w6 W7 u$ C) M4 `
"road. Either increase the amount of roads "
8 x$ V/ r7 t3 J, x% d "by increasing the GRID-SIZE-X or "% [9 A9 d9 | J4 z( t% J, c% s; t
"GRID-SIZE-Y sliders, or decrease the "
* B. @: e. L4 Q# ^% } "number of cars by lowering the NUMBER slider.\n"
: v% f0 V. K0 q: [6 I, C "The setup has stopped.")) R$ y! @4 ~4 R% M% w: x& p \
stop$ t8 X7 c. [1 U6 o" n4 I, V$ |# g
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
% Z% j1 Y, i! |4 l) H& s' R4 o! V& X$ @ crt num-cars
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setup-cars$ h0 c7 h' X/ b% c
set-car-color
2 x6 Y( X7 n4 R& k record-data
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;; give the turtles an initial speed
( _) w' C0 R$ s' J6 P5 j ask turtles [ set-car-speed ]$ N) z& f1 y8 p1 a4 l8 M" `
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reset-ticks7 t$ O5 k# \$ q9 W& E8 ]
end
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, ~$ K: V# p: t# I+ V" R;; Initialize the global variables to appropriate values! t8 w* Q9 ?* `" ^
to setup-globals
2 b. M2 u. k% [0 c* s1 B8 A set current-light nobody ;; just for now, since there are no lights yet4 y) X: Z$ h# _$ @6 Z- a1 B# E1 H
set phase 0
: N) ]9 C2 J2 n) Q" i1 `6 ^4 v set num-cars-stopped 0
T5 Z( k R+ Y. `+ J set grid-x-inc world-width / grid-size-x
! B; ]8 f& X: e; ] set grid-y-inc world-height / grid-size-y: }0 N& s5 W, |; f8 N% E
% D, j( c: q' c; P% E) l* Q ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
3 U# }8 e5 B) ]) a. C set acceleration 0.0991 z5 t7 }9 O v' E y: o" y
end
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& N# _1 _1 h; H0 Y;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
4 l# R: q" [! X) V. i3 |& D;; and initialize the traffic lights to one setting- G! D, \& w E& S
to setup-patches# S, R5 o. r: T( J! C/ m$ b& y
;; initialize the patch-owned variables and color the patches to a base-color: {7 W; q; \0 i, l4 C. [- J. l
ask patches
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) H; c$ H$ E" d) \" T% Y set intersection? false
: v; a. I: z# V set auto? false+ q" a- C/ t1 \* U9 D
set green-light-up? true3 g1 H) `$ m! M( n
set my-row -1* S, l' J. E& @1 R" L
set my-column -1% s8 P( f0 s3 L9 _5 L* @' g
set my-phase -1
& d3 F- P' Q Z( x' p$ F% g7 A4 J set pcolor brown + 3
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* J$ y7 c+ O+ t1 F ;; initialize the global variables that hold patch agentsets- D0 [% |8 `& G+ [" u, i3 l9 Y7 [
set roads patches with
# \; R c* N4 X" G, r' | [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or4 y0 Z+ L' z8 M) }/ w1 K9 ]) D
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 r' h# H/ y6 F7 }, ^6 I. L3 Q
set intersections roads with
2 A7 y' u# \, X% m$ j1 I' o! k [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and- C4 X0 g1 q W9 Y& c g
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 M F2 i0 n4 a1 i2 T; e, Y
$ ]6 T& l5 I# o& I; q# s/ _- \% K ask roads [ set pcolor white ]
% V) T3 n8 }' P2 ?, } 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?$ T. H" ~* q/ Y; T9 ^0 j c
set roads patches with# n# V# N4 E9 \4 I
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" C+ z V0 b" m9 b
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 b$ l( x/ Y7 t* O+ z5 `
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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