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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。' i+ k' k/ i$ ]$ Y8 `
netlogo自带的social science--traffic grid这一例子当中,
% ^, E6 y, w& M. ~globals9 n _) k- M* X9 ]+ O
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grid-x-inc ;; the amount of patches in between two roads in the x direction0 M6 C0 D# J; z: b. r$ A1 X
grid-y-inc ;; the amount of patches in between two roads in the y direction
; C6 Z" m) P8 d+ q5 ^% T) V acceleration ;; the constant that controls how much a car speeds up or slows down by if$ ~* X$ N; B% b" O2 @( T4 T
;; it is to accelerate or decelerate* h0 K1 K, n' u2 l4 ^" O
phase ;; keeps track of the phase
9 x7 a8 o! l3 g/ t num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure# c4 B6 k- H. ]4 m+ e7 v# V
current-light ;; the currently selected light0 ~5 I7 y$ E% u3 |" R2 D' a: n- a
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;; patch agentsets7 e6 f. K6 O0 r' G- I* `
intersections ;; agentset containing the patches that are intersections8 @$ j0 X0 k3 Q% \4 C8 C. w7 y
roads ;; agentset containing the patches that are roads+ g" @4 x1 {0 e% |1 g( j
]
( ~% @# L# o: L, y$ _1 |! h; w' H/ {$ y1 S" y4 g) G/ x3 r0 ]
turtles-own9 t P! q+ a( m% L) U. P* W7 {3 Q
[
" k% j& d8 Y% @# Y. U$ @( U speed ;; the speed of the turtle
/ i( L( _8 s8 A- x2 v up-car? ;; true if the turtle moves downwards and false if it moves to the right
+ T, |6 D8 F4 Y# D |8 F8 d: v wait-time ;; the amount of time since the last time a turtle has moved
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patches-own+ O \+ J: q8 V( \4 u8 o
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intersection? ;; true if the patch is at the intersection of two roads' k' v" p/ b2 b% T
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
9 O* I6 `0 Z" D' J6 [' Q5 b8 G ;; false for a non-intersection patches.
* h, q# G& z" B$ g9 s! }% S0 c- T& J' Q my-row ;; the row of the intersection counting from the upper left corner of the9 ^( K$ S2 Q6 x7 \ A* T
;; world. -1 for non-intersection patches.
$ X9 q' K ?$ l+ i+ I n; k; {9 \ my-column ;; the column of the intersection counting from the upper left corner of the
^7 C! y. s A( r8 J ;; world. -1 for non-intersection patches.
+ I5 X( @: {5 }" v, s my-phase ;; the phase for the intersection. -1 for non-intersection patches.
( C$ W4 i+ L* L/ z5 y; D- D3 r auto? ;; whether or not this intersection will switch automatically.
6 F6 `5 D; |! {' l0 D ;; false for non-intersection patches.& a S8 c) M) A1 W
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0 Y8 ~! q1 R- N3 b+ y) Z;;;;;;;;;;;;;;;;;;;;;;6 W, R( {- `, Q- l8 V
;; Setup Procedures ;;
3 _8 ~. W. ~! M4 |;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.* h) |' k" w8 I2 Y9 I: K
;; Create num-cars of turtles if there are enough road patches for one turtle to
% B7 d# [ Z9 B' Z. ?;; be created per road patch. Set up the plots.
/ @" G) W5 q( n2 f) u9 v0 nto setup
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setup-globals3 F4 p9 ` R5 V8 t. w4 d
+ a$ O! S) C1 w+ X4 n ;; First we ask the patches to draw themselves and set up a few variables
5 @0 C. m) A6 v/ d# c \% T7 i, R setup-patches& G( N4 ~* ^/ c" D
make-current one-of intersections% T6 d; l* t1 U8 j. E
label-current
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set-default-shape turtles "car") ]7 i4 s5 H4 w/ \ S1 @: b
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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 "* @+ d& F3 ]. j1 B8 y0 m
"road. Either increase the amount of roads "0 q7 p8 q+ ?6 A3 d
"by increasing the GRID-SIZE-X or ": l& _8 _ s8 h2 N
"GRID-SIZE-Y sliders, or decrease the "3 z( D; a3 ^$ |2 T" e2 v
"number of cars by lowering the NUMBER slider.\n"
( K$ E/ n2 e/ a# A$ g) z4 n8 C "The setup has stopped.")
! d0 l1 U3 I$ @7 ` stop
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2 R( H6 q0 f; V ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
+ a/ b' G+ P) l! Q: e) \ crt num-cars' C, C# j+ m, s
[
4 p+ j! u8 X) o# o8 u& \ setup-cars
, ?+ V2 n3 u/ x8 J+ W) T set-car-color+ K0 K; [3 K, P* B* F
record-data, Y V$ m$ P" V! ?# ~8 g+ |
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;; give the turtles an initial speed& Y7 Q& Q4 l1 r5 M- m* L
ask turtles [ set-car-speed ]
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reset-ticks( R" O: C* }- I& D) }0 d7 V5 ~/ S4 ~
end! G1 T& h8 U3 b4 w X% X3 X
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;; Initialize the global variables to appropriate values
. @4 A7 a4 L$ p1 e8 \to setup-globals
X n2 `8 e4 o# ^) `4 m3 R set current-light nobody ;; just for now, since there are no lights yet
% A; V% Y6 F( s' K& a set phase 07 t0 K7 d1 L/ ~
set num-cars-stopped 0
% N: x/ j, y; x. M+ t( z2 Z set grid-x-inc world-width / grid-size-x/ [0 S h1 ?* \
set grid-y-inc world-height / grid-size-y. \2 [: o4 P% N& V& [
, z: v1 D0 T- B6 B ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary0 D. n/ N! K% V% u
set acceleration 0.099
) p' O: f% P. A8 U, t: \( Cend. J# `8 z6 |7 k, Y8 F
5 Q8 A$ @6 A; Z2 {- K, X;; Make the patches have appropriate colors, set up the roads and intersections agentsets,1 }# d' F3 k8 M/ A8 i& B# O
;; and initialize the traffic lights to one setting
* d& P9 F7 p* \ i- p' U4 Z/ L1 e" nto setup-patches( o8 Y, q4 Q6 E
;; initialize the patch-owned variables and color the patches to a base-color
; ^+ s& y! e: s" g! L7 Z3 { ask patches
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set intersection? false
/ h, g6 t9 |; s q B4 C set auto? false- z: f* t: ~$ D% h
set green-light-up? true
i& k: Y- Y9 j: e% H set my-row -1
/ w3 C+ }* p$ a set my-column -1
" z4 V& K- S! H- @' E set my-phase -1
( s6 B) k; m6 k1 e1 r7 J set pcolor brown + 3
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$ }7 C" r0 A# H3 O( u% r/ D. c ;; initialize the global variables that hold patch agentsets9 s6 h @' j1 K; R6 w, {7 q% j
set roads patches with
3 H5 `# S Q$ q# M9 s+ I [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
. J* S" [6 X. c7 c5 A' O (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 F/ m$ d; V. \8 B set intersections roads with; ^; ?0 X: x( G* J7 G
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and& X, _2 ~1 f. t% S
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
3 M$ W+ t: g! F' w setup-intersections0 c3 G- P7 P y# ]8 J5 |5 {% B
end
3 ^7 P, j1 J5 A9 P( Q其中定义道路的句子,如下所示,是什么意思啊?
7 {) e) T1 x' o; P, s set roads patches with/ J0 n, g7 P$ e. X
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! \# s# `! M8 Y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 c2 x1 m* Z1 X/ u3 E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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