|
|
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。1 D6 h; [/ y/ V! D0 _$ i
netlogo自带的social science--traffic grid这一例子当中,2 l& y& \' m+ a; k* l. \ u) y; g& x
globals
) y: N3 \5 K9 N6 {[
: a6 H/ v1 u& W1 s grid-x-inc ;; the amount of patches in between two roads in the x direction
0 n4 k& P0 I% B2 H: [8 Z" {2 `6 [" Z2 n grid-y-inc ;; the amount of patches in between two roads in the y direction
( m/ ~2 ^8 }& \ acceleration ;; the constant that controls how much a car speeds up or slows down by if. k; _' H2 Q- c1 ], L$ v& E/ R' H
;; it is to accelerate or decelerate! Z3 S6 d- W, Z2 q! \
phase ;; keeps track of the phase& I; s/ T# K/ c% a; z% a% P, h9 P
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
/ ?+ ]4 q0 t1 O. U/ G4 a current-light ;; the currently selected light& A' H4 n* `' e g0 E! E0 W
! |2 S5 e: p- r0 K6 r* o& D# o5 S- n
;; patch agentsets
5 m, m- v& [ e8 L' s intersections ;; agentset containing the patches that are intersections) C s& a% S# u5 O7 V' s
roads ;; agentset containing the patches that are roads% F( [( g7 ?, A5 ?) \; Y$ e
]
" B( H s8 P4 U( m# {7 Q: V7 d7 u1 R, H4 n8 _: d. E; C
turtles-own
' h# u- D' r/ t9 |7 x9 |[7 T7 h2 r, T% j2 h6 b& p
speed ;; the speed of the turtle
, o2 T. j: |8 s. f up-car? ;; true if the turtle moves downwards and false if it moves to the right$ G0 O8 {8 c' G n/ m# t8 ^
wait-time ;; the amount of time since the last time a turtle has moved
9 g3 x# \- {# j- b% n]
% c. L( h; l C8 [ B
- h' x3 g1 } \0 V/ V% U6 I+ Upatches-own0 Z6 B( B" E' @; k) V6 P5 E
[9 |) Q Z! H1 a; N
intersection? ;; true if the patch is at the intersection of two roads
6 s) { p2 [& W4 T9 ~& `4 r+ e& B& S green-light-up? ;; true if the green light is above the intersection. otherwise, false.
6 j1 S. j$ u1 t& R( T7 f( Y6 H ;; false for a non-intersection patches.
% X" @( \8 U. H$ E) P my-row ;; the row of the intersection counting from the upper left corner of the' U K$ E3 }* ~; w
;; world. -1 for non-intersection patches.
1 O9 ~3 `( T4 E my-column ;; the column of the intersection counting from the upper left corner of the+ v* d3 B. {2 J! H( R: c1 o4 S
;; world. -1 for non-intersection patches.
$ u7 F1 M' s" I. c- S my-phase ;; the phase for the intersection. -1 for non-intersection patches.
/ k% |: L/ c/ o3 s/ N auto? ;; whether or not this intersection will switch automatically.
9 n( Q' L' A/ \* Y$ r- c ;; false for non-intersection patches.
+ u1 W5 M5 p4 W9 ^5 e; }]6 D R v; ^' Y. {7 [) d! ~; A
+ m3 X1 J8 O. d7 G
" K" u% a: P" \7 w7 P( X. v
;;;;;;;;;;;;;;;;;;;;;;
! F0 K. r* B: x1 i' a;; Setup Procedures ;;
+ @+ ~. H0 o, Y2 }$ j' b6 O- q# b3 t;;;;;;;;;;;;;;;;;;;;;;
& X, A5 B+ d' @) E! ~5 r7 b: f, h# `, q+ |6 J3 l( ~
;; Initialize the display by giving the global and patch variables initial values.2 F, p. w% i* O4 `
;; Create num-cars of turtles if there are enough road patches for one turtle to$ x0 M- ]# d1 n3 @
;; be created per road patch. Set up the plots.& X0 A( D( l" B: B1 ~9 A
to setup- e: A) A/ h( @5 m# ?! h
ca' T8 ~* I9 Z9 V9 c* y) r
setup-globals7 f$ ~7 o# R* _
# O# H! w1 B S2 z/ X ~- F ;; First we ask the patches to draw themselves and set up a few variables
( L- |8 ]4 d: t1 H* M n1 [ setup-patches9 Q$ J( A# T1 q5 z
make-current one-of intersections
1 i3 N U% J' u9 g label-current
. |3 L/ \9 K) J: b% p }- V4 s$ O. x. H C1 M
set-default-shape turtles "car"
2 f1 ?5 _7 H$ H
1 u6 J! P: W! \8 C; a" f( a% H if (num-cars > count roads)
: B( `% Y5 u* u0 M [8 b8 z! B% N0 B t: G3 G
user-message (word "There are too many cars for the amount of "
, f/ h! d+ W( { "road. Either increase the amount of roads " n4 i! ]+ O) z2 p) @/ q4 E
"by increasing the GRID-SIZE-X or "
6 ^3 K6 O2 U: P8 E+ }( H "GRID-SIZE-Y sliders, or decrease the "
: m& I% o: a$ ^ t+ P! K( P "number of cars by lowering the NUMBER slider.\n"( P7 ]$ @( {' l7 j2 s
"The setup has stopped.")
) M- r0 I- R. e7 W D1 F stop
- H* |( t5 g3 {- g- |- g! @ ]
$ Q" f' W4 |' p
# F# K, ~+ K! B# G) y1 J9 ?/ A' d ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color$ G8 \& }; ^/ d( I
crt num-cars
4 u% }: p3 Y7 A. w [) K0 E( ~- n9 H, [2 P, {+ o( c
setup-cars; P0 r4 _/ p4 f: o
set-car-color
7 p0 g+ J" H7 o3 d7 @ record-data9 I% r& X* ~! m& J
]/ C' z& n* j# ^
; {$ R( w: ^2 ]- N ;; give the turtles an initial speed0 o$ _" i! x6 ]+ t# z5 g+ c
ask turtles [ set-car-speed ] U! _0 F' O4 \
' w6 U4 F* G1 S& H; S. }% J reset-ticks, F2 ?* `. l8 t! v
end8 x+ a3 f/ i1 X6 }4 h
2 i% L& N; f0 N/ o4 A' J! v5 g$ |) y+ a, z;; Initialize the global variables to appropriate values7 [9 ?2 m* g0 g- @2 t! j/ S2 _
to setup-globals' }+ y m& R8 D& Q- u" d, N2 B+ T! u
set current-light nobody ;; just for now, since there are no lights yet
# u) v& P) A9 p- B# O7 c set phase 0! O# G; v }- C0 [$ a& E
set num-cars-stopped 0
3 O- N' @0 Y) ]5 k1 W& s" i set grid-x-inc world-width / grid-size-x" v, J1 d- \$ P I" {- ^1 ?6 b
set grid-y-inc world-height / grid-size-y. {3 u; K# W6 G C+ G1 r/ M
$ c( _: `# O) P- W! M
;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
" a: B. R% S+ Q# H set acceleration 0.099
7 ^7 O( H! Q7 S1 e9 Tend
6 `8 I6 d6 u: H0 [" m- m8 q
0 \5 W% p$ ~7 j;; Make the patches have appropriate colors, set up the roads and intersections agentsets,7 J/ R7 W+ \/ J8 @
;; and initialize the traffic lights to one setting, a! m; X8 F1 N* Q9 Y
to setup-patches) }5 K1 V" ^5 G. S
;; initialize the patch-owned variables and color the patches to a base-color
2 d. ?3 Z( C* a a* W! D ask patches
8 D4 f4 w: ]- k( G$ S5 j0 K/ m [' H9 w3 y% [& L0 D7 @0 ~
set intersection? false& o: I6 V5 o7 v2 S5 ?4 `6 b
set auto? false L) D! `! q) K6 B7 Q4 y" Y# f
set green-light-up? true
6 `. a3 s8 p; a6 \% _3 z set my-row -1
6 x! S, Z" y- K% l set my-column -1
6 N# W5 L/ Z- ^ set my-phase -1; T j F3 d" I$ B0 a5 _
set pcolor brown + 3
5 f- n1 B6 V# o4 U& @5 F5 C3 m& l ]
/ z4 A7 b* X# R+ L: g9 i5 t( [* `& ~2 O8 q
;; initialize the global variables that hold patch agentsets
( |' T, ?! L2 k a1 j0 Z8 \5 M set roads patches with
: |- Q! i e* @ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ N, E( `! ]/ ~3 u1 u4 y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]) j7 s9 n$ b+ d/ Z" u3 l, H' i
set intersections roads with
$ l, v; {6 d. m8 g" Q' D/ B9 r7 Z [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
2 F) I: N9 X0 H0 R+ m0 N/ [6 a6 \- |6 x (floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 Q; g9 K- j! z r# K$ c' s
0 h8 {3 P+ w; v. g! T% t
ask roads [ set pcolor white ]! Y9 b- e; i+ W% f/ ^
setup-intersections) s9 l. {& i$ W% s9 n
end/ Q8 ^7 p4 x4 P9 |+ `- s. D# t
其中定义道路的句子,如下所示,是什么意思啊?4 G& R5 P5 q9 K$ a
set roads patches with$ t: }, d0 r, g
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% b' F& ?' S) Z ]7 m( R7 \# p
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 P3 C1 j: J& b' w6 |/ x
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? |
|