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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 W& W, t1 Q; u& P" y5 l
netlogo自带的social science--traffic grid这一例子当中,. n% |4 K6 e! g# J
globals6 n/ n2 o# K2 T8 i" [
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grid-x-inc ;; the amount of patches in between two roads in the x direction: D. P5 x. {3 j, @6 Y; Q
grid-y-inc ;; the amount of patches in between two roads in the y direction
0 E9 b! k) S# Z+ `' x acceleration ;; the constant that controls how much a car speeds up or slows down by if
" ~: V& m) T5 X0 l. F! `4 t ;; it is to accelerate or decelerate" F" ]- v6 R9 p, O7 d3 h
phase ;; keeps track of the phase; c D8 H, k- r" Y& a% O
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
- A" ]" w8 J3 K W& T& { current-light ;; the currently selected light; `; i/ S& w! J7 `
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;; patch agentsets3 Y( P! e: ?# G5 C* c9 V7 R
intersections ;; agentset containing the patches that are intersections
8 D% T. U) B0 @1 h roads ;; agentset containing the patches that are roads: M4 ~0 D9 D1 Z* H1 [6 V
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turtles-own( {( W9 H; A; x g
[
/ L% N3 r2 p8 i ` speed ;; the speed of the turtle/ I( q1 z$ j6 m: y7 V8 K
up-car? ;; true if the turtle moves downwards and false if it moves to the right
, s. b; e) `2 L9 y$ W) P4 b) d' f wait-time ;; the amount of time since the last time a turtle has moved
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) V$ m- Z$ k) _, U8 j) Upatches-own
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& x: S! R) e; \1 R" a) J) H/ ^, b intersection? ;; true if the patch is at the intersection of two roads
, j; ]# m: F' y# x1 z green-light-up? ;; true if the green light is above the intersection. otherwise, false.
, s' @7 n5 j$ X4 S, b! l ;; false for a non-intersection patches.
1 j7 k4 b y% D4 ]5 m2 E. z$ Q) [9 e7 T my-row ;; the row of the intersection counting from the upper left corner of the* a; `% ~2 G2 k
;; world. -1 for non-intersection patches.
7 z, o$ S- z4 H3 q3 C: A my-column ;; the column of the intersection counting from the upper left corner of the/ P3 O5 ~ q; l" W
;; world. -1 for non-intersection patches.% D9 N4 H4 f# ]7 {# Y5 h: r5 f
my-phase ;; the phase for the intersection. -1 for non-intersection patches., ?' N6 L( D) {+ l/ j
auto? ;; whether or not this intersection will switch automatically.& T. X" w* |# E9 ?: f* ^; b& F7 g
;; false for non-intersection patches.
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/ Q/ \, s, Y L9 ?;;;;;;;;;;;;;;;;;;;;;;: r& x7 _- B# i+ Y$ u: u8 x6 i
;; Setup Procedures ;;
9 S# }/ j& W- L+ [;;;;;;;;;;;;;;;;;;;;;;8 A" W) H* l1 v; Y! v' ^, l. R
, Q; I W/ D5 V, X: {$ N o;; Initialize the display by giving the global and patch variables initial values.
# h7 P8 g& u. T# X;; Create num-cars of turtles if there are enough road patches for one turtle to
1 z0 s4 D* w! n# d! t, L( b F5 p8 M; ];; be created per road patch. Set up the plots.
$ k( S- | u: I$ S# i2 D9 eto setup9 V, {% G' C: @. E% w' }% I
ca
8 ~- F \ Q4 }" R" Q setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
1 \ Y2 m4 Z' Z) n& r4 m7 G6 f9 p setup-patches
$ B, V' w2 E. ] make-current one-of intersections
' c0 A- O& |/ f5 I, H; v label-current( t- Q5 t3 V" P2 o5 Q' ]$ }
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set-default-shape turtles "car"
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# Y, x! C* [# T7 \$ a$ x2 t3 |. L if (num-cars > count roads)2 i& `7 C( v% W; r) k2 b5 e
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user-message (word "There are too many cars for the amount of "# Q U! ]8 ^6 w6 o& s
"road. Either increase the amount of roads "
2 b' v, J6 o0 e, ~+ a; ? "by increasing the GRID-SIZE-X or "
" ^$ d# x ] |- } "GRID-SIZE-Y sliders, or decrease the "
8 K- A) o/ ^/ [ "number of cars by lowering the NUMBER slider.\n"$ p" o' d) T1 ?" f! b/ z }
"The setup has stopped.")
) L1 a; q9 i0 i* V' Z8 J stop2 l/ m: ^/ H' A5 x& J7 t
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color5 ], t' y4 w) ?* m. g
crt num-cars
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setup-cars
8 \# m) M' l9 D; ] set-car-color
+ g% s E* t' J" P record-data2 M" R" _: t% ]4 Z' Z
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3 R" X; w, Y! a0 `" ?! b! c ;; give the turtles an initial speed
2 Z) a" }, I3 d# E$ X ask turtles [ set-car-speed ]* Z6 Z. m, Y# Q5 l
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reset-ticks
" o x6 |. B( A9 b Oend
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;; Initialize the global variables to appropriate values
" D1 g; w+ H9 s$ U# p, n3 vto setup-globals
4 o6 T* P' Q2 g1 i3 z set current-light nobody ;; just for now, since there are no lights yet* E; u1 t( Y2 c( n
set phase 0" Z' H0 N/ T/ R: k2 o- \
set num-cars-stopped 0% s. p) i8 f; x0 C
set grid-x-inc world-width / grid-size-x
8 T" L: y2 c( I$ x& @ set grid-y-inc world-height / grid-size-y
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- C# Z$ I1 B, c- F, u' @; O0 f ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary& ?1 d- }' |: K) T( W9 I4 W4 y0 V
set acceleration 0.099# g5 h. Z3 p0 e6 X/ J
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,7 d/ y; k2 A" D
;; and initialize the traffic lights to one setting
, S4 E2 |2 C7 F( k5 Lto setup-patches- W+ i8 P$ k2 q c0 [& G( x
;; initialize the patch-owned variables and color the patches to a base-color2 M/ y+ }) O$ D9 ]% b A$ p
ask patches
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" v) \! P; N6 `7 f$ j, y" a set intersection? false& d6 U- [3 k# j. v( d4 u, B7 E9 y
set auto? false
3 H7 Q# F# x) l5 B set green-light-up? true
. S7 T4 d, g$ w) S A set my-row -1
" i4 W; _+ b* w) |/ {7 r& l: W set my-column -1
( Q6 L8 H% t! [7 C set my-phase -1( C e9 H& Z0 I( x% M
set pcolor brown + 3/ e. c7 @( O' x: C5 |
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6 p# c- p( ]. t ;; initialize the global variables that hold patch agentsets
& |8 d8 j- b* m( G9 {$ n; K, j, G( e5 C set roads patches with$ ]: h, O1 z+ d' Y" e( b8 O
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' f2 f& H9 g' e (floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 l& ^% `, C0 Z9 X
set intersections roads with i' m+ j& j! p& l) \
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
& U9 y1 V5 B8 i% F! u( r/ w1 U (floor((pycor + max-pycor) mod grid-y-inc) = 0)]( g! H' H9 f% R1 C- a7 @# O: x* x
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ask roads [ set pcolor white ]
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0 I$ N$ ^( M& T7 i7 f$ m. _' A; Uend
! C+ f5 [* I1 U) O }$ G其中定义道路的句子,如下所示,是什么意思啊?/ Z9 w' p+ S m
set roads patches with7 K! r% U; M# ~3 d; |- ~& ?
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% G1 `9 [# a! j% k9 t; E
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]& \) l; m1 G4 G" P" R# Z
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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