|
|
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。2 d5 U! B- N0 T t) Z. F, w) i
netlogo自带的social science--traffic grid这一例子当中,5 r9 m/ d7 p0 ], L+ O5 `
globals
- d# u! d* X. ~& g[# V( I/ d$ G% \
grid-x-inc ;; the amount of patches in between two roads in the x direction
) X% `5 j8 J' Z% c! J grid-y-inc ;; the amount of patches in between two roads in the y direction/ [+ d( G' j2 B
acceleration ;; the constant that controls how much a car speeds up or slows down by if/ V' l# t' A; w K) I C/ l
;; it is to accelerate or decelerate
* ?* J; j; V2 X+ a phase ;; keeps track of the phase
" ~ ^# h* w8 j8 h; O1 H4 a0 } num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure# P( ~( z& D7 W# V/ I& U
current-light ;; the currently selected light
7 t3 O7 J" _ ^: F7 P G! S/ y1 K! Y: G6 \# Y$ M
;; patch agentsets
4 t. j+ [6 b& r$ E intersections ;; agentset containing the patches that are intersections
4 H9 |" {$ X0 j, p8 q+ r( t roads ;; agentset containing the patches that are roads
5 z: [3 @1 F+ R) k: ~* Z]$ M) c; p/ H6 w8 f2 M: s! x. |; T
2 u' A/ t7 `! _* x; h/ L" ]+ Sturtles-own
$ z _& t( }+ C* Y! W6 \[+ d% v4 M5 L5 P) S9 G8 }+ P& Q
speed ;; the speed of the turtle6 b7 U0 m, S; V4 ]; }/ i6 S
up-car? ;; true if the turtle moves downwards and false if it moves to the right
) ?; [4 H. f' P, _: O1 H wait-time ;; the amount of time since the last time a turtle has moved
4 L2 V. k8 E; O& V: V8 V6 Y) X]. r% |9 r! s% J# X+ B, f0 D
: Z' Q) E' F* J* q8 v* ppatches-own! i+ O4 J2 j6 P3 w0 ^1 K1 [& ]
[
4 ^, [& ?9 e* R# X' T6 a intersection? ;; true if the patch is at the intersection of two roads/ i) u' _' e6 q1 f* ?# \
green-light-up? ;; true if the green light is above the intersection. otherwise, false.8 f% f! s: _' j) i3 N" Q L! A k
;; false for a non-intersection patches.0 g( _, g. | o8 H1 X( w7 u
my-row ;; the row of the intersection counting from the upper left corner of the
u- Q/ B& a r6 V# K/ c ;; world. -1 for non-intersection patches.& r" J2 C; p9 [' C8 T
my-column ;; the column of the intersection counting from the upper left corner of the
; F6 U8 L' L6 S+ f4 A" L0 U ;; world. -1 for non-intersection patches.2 @* k1 Z5 S% w1 `: W
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
. u$ [! K+ p: Y. d8 j( y; p9 \ auto? ;; whether or not this intersection will switch automatically.: f I" u3 [( m5 T; H. `
;; false for non-intersection patches.$ X% V9 e+ x' r! A; g6 k
]
- O# L0 M% H% S4 {) ~5 u: P3 }. i# Z0 M& ]& @ B( c7 a
- z" ?: F( {! |- y d
;;;;;;;;;;;;;;;;;;;;;;# E2 ?0 N4 E. ~& m1 w h2 {7 G6 W! ]( |
;; Setup Procedures ;; W( F" B5 L) e; H- X* q0 L
;;;;;;;;;;;;;;;;;;;;;;
' A8 I5 M$ y- |, H' Z
6 X, U! R- S: d$ c0 j* f;; Initialize the display by giving the global and patch variables initial values.
# Z8 P* O% _9 U H8 g+ Q;; Create num-cars of turtles if there are enough road patches for one turtle to
. K. k/ P' T" @, E9 k;; be created per road patch. Set up the plots.
3 W( B$ Y$ }/ z. F3 @* h; m+ fto setup! I# P4 Q( u) H
ca$ K/ O' W: n0 m. {; M
setup-globals4 [. R4 D) j) l( B2 _7 m+ B
0 P0 ^' K: a0 [& [ p" P* _ ;; First we ask the patches to draw themselves and set up a few variables
/ R( f' s* b: m' E+ I setup-patches/ s3 _2 ]* L* `/ X% M( E7 M' u4 e
make-current one-of intersections) y0 ?" I+ s" x" I4 Y5 N2 [! D& `
label-current
8 {0 r% u' ]9 Y \2 i' W% e# e/ G/ G) Y- e8 } M: i' N+ G! g
set-default-shape turtles "car"
4 ^# ? k; @" g, S% j; y
1 X7 v F" G9 N1 u+ S6 R/ q if (num-cars > count roads)
% M% Y+ y& q2 @; U( c [
' M' }# W' D" p1 R2 {" P user-message (word "There are too many cars for the amount of "
, `9 p7 X1 {, Q) ~/ J2 i5 c$ K "road. Either increase the amount of roads "( {) C, i( D6 Y8 {. U1 h
"by increasing the GRID-SIZE-X or "
6 F4 p2 _7 g9 x* ~0 X* u3 z5 @5 F: }3 _ "GRID-SIZE-Y sliders, or decrease the "
) I9 h2 u: B% C6 j' f' d" v+ n, ^7 P "number of cars by lowering the NUMBER slider.\n"8 s! O2 f2 x& L
"The setup has stopped.") O7 \" D+ e, e. z8 X) @
stop
: x- U! D; {% H# `5 j7 a ]
4 q* a p1 m& ?+ G+ [. b) b
: M& L7 p1 P- c" f0 G* e ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
% }- q8 `4 z9 `% J0 q3 p; c* ? crt num-cars
2 r. w. L6 [. V+ D( | {2 h& _ [
- V/ I" g6 L0 {* e setup-cars
' C$ {& g6 @! n. Z6 h set-car-color
! V- j2 l; B, p& o' L record-data
# `& z- V% W& b. o ]: N( Y4 f {% b) ^; {
1 K/ x! ]- Y2 D3 p+ d ;; give the turtles an initial speed
/ P$ z3 z# n6 _2 E7 ~ ask turtles [ set-car-speed ]
- b$ `; j' s: \! h$ ^ H* h3 l5 I& ?, q
reset-ticks
; _1 R! v4 e& r1 _! lend
, J, b; z# ^1 B0 Z
. p: b H. E- E7 Y: y;; Initialize the global variables to appropriate values8 p) d3 C# H3 w
to setup-globals
' t& n6 Y1 ^6 j; \1 v# |! q set current-light nobody ;; just for now, since there are no lights yet( ~# J# B4 ^. M
set phase 0( h! u, F; R4 M1 i' I+ S4 ^6 g
set num-cars-stopped 0
- _+ C ?8 w& h9 \ set grid-x-inc world-width / grid-size-x
& v& w+ b4 g# ^3 R5 b; G5 F& m set grid-y-inc world-height / grid-size-y+ p+ `4 {7 e+ y- S) b
: @5 o6 c( c$ _ ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary8 |/ \' H1 P. [- h9 q! J
set acceleration 0.099
+ U4 ]4 A7 O) ~" i5 Kend
% @' f3 c/ e* ?1 R2 W: D' o3 U0 c% h' _5 |
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,* ?, C0 g1 u( n$ ?: f( i- J
;; and initialize the traffic lights to one setting
2 }+ P# j1 W" J' t! Xto setup-patches
+ M( A. U& @( C' x ;; initialize the patch-owned variables and color the patches to a base-color
% j6 m$ |2 e0 g* S1 P0 h ask patches
4 e1 E6 i4 ^( ~. c [0 [8 P. m4 U! \' Y% |
set intersection? false
+ |; s' f, Y0 ?, F S7 D set auto? false8 c( c9 D# O# W5 K' u
set green-light-up? true, x- ~/ @) c% e* F( [+ o
set my-row -1
8 n: y9 w! O# U7 p set my-column -1$ P5 p) u9 L) T7 k3 N) l2 [* {7 s
set my-phase -1
1 o8 _4 p9 \! E1 j2 } set pcolor brown + 36 K) g( _5 g4 m# R, a/ w+ h
]
1 G' Y9 ^ m+ ~( v- q& t k$ R1 M, z
;; initialize the global variables that hold patch agentsets8 O& o0 V) J' y! T9 B. h
set roads patches with
( ~0 F. w) C2 M. O5 \ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 o7 T: r5 u2 U) w& x (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
f' f& D3 b A set intersections roads with; j/ W7 U- s4 r) I. Z) N
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
: j( C0 _4 e4 a4 E" W' z+ S# g (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. _. N9 I4 u* v4 T5 E$ ?$ M, g. Y" s% l' P5 p, _; x' \
ask roads [ set pcolor white ]
. F' N5 M; v& i; A8 N, }# r, L setup-intersections
' J" w; s' f2 J' o( Tend
2 T; ]/ D# j! E% L4 ]: M其中定义道路的句子,如下所示,是什么意思啊?
7 j0 \8 k7 R- l- G1 p a- ] set roads patches with t* H: `# F3 u' K P0 b
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
$ L! u) ]0 J1 ] ~ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 ^# o$ M8 ]1 F3 G
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? |
|