|
|
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。
* b6 m) X% M1 ~& n6 D# cnetlogo自带的social science--traffic grid这一例子当中,
3 `. \- ]2 @8 ]! \( k" Dglobals
! c4 y- t8 U$ `0 H2 F7 M[, R- h3 L5 Y7 {
grid-x-inc ;; the amount of patches in between two roads in the x direction
: g- B5 u3 t" L3 C+ W0 W grid-y-inc ;; the amount of patches in between two roads in the y direction, q. ]# R# ^$ h; h
acceleration ;; the constant that controls how much a car speeds up or slows down by if; C1 y8 j- B8 T6 U
;; it is to accelerate or decelerate
; \9 g( H& ]( X9 _% {+ K8 b phase ;; keeps track of the phase8 L! m4 Q2 w0 u4 n/ a. B
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure/ G8 Q' [0 x0 c, K1 [/ ?0 |" J
current-light ;; the currently selected light
2 A1 E' b1 n7 f# E& a) u
7 ?0 F! U- J% e6 f, T. @* s ;; patch agentsets
, m9 U0 C: q$ R intersections ;; agentset containing the patches that are intersections9 N6 Y" B1 b9 N0 C D) N! \# N
roads ;; agentset containing the patches that are roads
$ v' v3 x+ c4 U- r2 J3 L3 q]
) U& I- a6 f' c2 S2 j& Y" H& e% Z, {# y/ ]9 [* B# P
turtles-own
+ I* s* O& J0 E" \# i( R[7 @6 [0 Y3 b( E$ f; |2 B7 a
speed ;; the speed of the turtle
4 a" f9 [; ~& k3 n! O& h up-car? ;; true if the turtle moves downwards and false if it moves to the right
9 T7 j/ {3 W0 X wait-time ;; the amount of time since the last time a turtle has moved
5 e6 V, _3 C+ ^2 A' Y! T R]$ }, m: l( z& S. s
$ V+ R1 W) i7 e! _. F9 E6 e3 W+ wpatches-own# L* E' S3 Z- }$ \
[- H# I5 Y5 `# Y" c/ i, Y" u
intersection? ;; true if the patch is at the intersection of two roads' u, r( Z% q( i1 p( D! u- K
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
: [; ?$ \/ _5 S ;; false for a non-intersection patches.
8 f, O/ V2 s4 L my-row ;; the row of the intersection counting from the upper left corner of the9 ?, e* v! h" w0 d# L" ^1 Q
;; world. -1 for non-intersection patches.
9 Y9 h; L$ p( @% @" H& }+ k my-column ;; the column of the intersection counting from the upper left corner of the
1 W5 ]! I1 X3 Q$ d/ `: W ;; world. -1 for non-intersection patches./ L1 w- q8 v& S/ d9 C
my-phase ;; the phase for the intersection. -1 for non-intersection patches.4 h2 |: [; c5 B; i
auto? ;; whether or not this intersection will switch automatically.. G( Z& C* C3 w( v( L
;; false for non-intersection patches.
1 j+ E/ d. x! n) m/ M]
6 n# |# @" U, j Z6 e' s& g% L5 x6 m/ w$ [" h# m' f; S: G
1 m: k* R" E1 L% c9 X
;;;;;;;;;;;;;;;;;;;;;;
8 D" Z1 K# g( J8 r0 A* d;; Setup Procedures ;;
% K) U$ t1 V8 h9 l* v: L* u, v1 V;;;;;;;;;;;;;;;;;;;;;;
9 k. `1 G) H O4 V0 e* y/ `) R% ~" H; v$ [( _" M
;; Initialize the display by giving the global and patch variables initial values.4 E+ x9 w# B+ {; U1 |
;; Create num-cars of turtles if there are enough road patches for one turtle to3 T! o3 `% j P# K' X
;; be created per road patch. Set up the plots.
% T& k) B d4 R# T1 r- wto setup9 m0 ] F3 H% `, }
ca% M/ K! y* E3 ]7 x9 f* M1 _
setup-globals9 L' i: \; _, ?/ ?
, l& L" E) t- v2 S4 k$ p! Q ;; First we ask the patches to draw themselves and set up a few variables
* A% V# c: H* y8 O setup-patches
3 @( `) S$ u0 d- _; e; k$ ^ make-current one-of intersections
; g3 q2 l" {0 ^! o/ A( i label-current. C% T& ?. }8 O( ?3 e: i2 `
3 S6 r/ x$ u d* m" e, {; G# A
set-default-shape turtles "car"' n" L* A. E# b8 {! b* W
. h& M Q. `" n5 V, W7 F if (num-cars > count roads)6 ~6 D& c z9 c& q9 H* w
[' g; j4 e4 {6 P; L2 \' x
user-message (word "There are too many cars for the amount of "
; @, z1 B3 J# m% F# u$ ` "road. Either increase the amount of roads "
) z' @# s: _* _ q' M "by increasing the GRID-SIZE-X or "7 ~3 } @4 U" [0 D
"GRID-SIZE-Y sliders, or decrease the "
8 C( H- T' N2 l "number of cars by lowering the NUMBER slider.\n"/ Q, P: q) O7 A% I: `
"The setup has stopped.")
1 c% [* i+ n$ B z3 v: k- ` stop
" v4 W* C+ m, y' _ ]* @. z2 K. J1 q6 g
6 z/ K2 D/ q3 O
;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
" j+ Y) E. i, M Z0 z+ a @ crt num-cars
, o% I* a; `. E3 T. h8 Z [9 `* Q& p( j y3 ]% g
setup-cars
' z$ {' i# w) S) Z2 p set-car-color1 J- Y P- N% V
record-data
- H+ D v% x; n/ M ]
: I6 ? a- J$ E" K& A: I9 ^1 g o+ H! c# n5 e- p0 p, k9 }
;; give the turtles an initial speed
4 s n& C1 ]* {5 ^- c# m. ~& o ask turtles [ set-car-speed ]( ~$ ^ u8 q3 T7 J$ G
: {) Z9 A4 P. e# ]% F) T6 }) c* h
reset-ticks
$ A+ v; L4 s% Pend
; Y) J+ W8 f( ~/ {3 M% _. o
- {2 d' Y* @6 d8 ^+ b;; Initialize the global variables to appropriate values0 |6 G# ]5 J( r9 |* ]6 s# A
to setup-globals
* b1 g+ A3 A/ { set current-light nobody ;; just for now, since there are no lights yet
$ N6 b9 ~$ a& b3 f% M set phase 04 T3 Z0 n: ?3 n9 [+ ~
set num-cars-stopped 0/ T* |$ _, k* O( {6 V4 Q r; U
set grid-x-inc world-width / grid-size-x3 @ ~, E' r( k0 P$ b1 c
set grid-y-inc world-height / grid-size-y
4 w: C7 c2 }9 F5 d5 D& |5 _/ x( X* D7 n
;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary! k" m% F: H r: k
set acceleration 0.099
6 z& W A) i5 tend) P$ m2 s" ]7 h
* T0 ?, N7 L6 ^+ V& _;; Make the patches have appropriate colors, set up the roads and intersections agentsets,+ N% N/ V& K9 o& B8 Q6 b
;; and initialize the traffic lights to one setting
s) l+ x% y8 f4 Vto setup-patches
0 `2 B' X3 E, q6 }" @; m( {9 Z( k' I ;; initialize the patch-owned variables and color the patches to a base-color
) {; S- Q- n& F% c* m ask patches
2 |- D1 A2 T6 p' `* W& E0 g0 C [7 d, l( u8 t( ~. f- b
set intersection? false
( o2 a/ l4 `4 m5 b set auto? false
9 T/ R& g C6 ~9 H- D: J7 W" L set green-light-up? true* |' D2 d" s; T, { D* M6 M9 G- O
set my-row -1
3 ^. @: o! A, O8 ` set my-column -17 T( T2 L! x" C' E& n
set my-phase -1& p9 S. k& Q% M. J' \; x
set pcolor brown + 36 S3 u' Z' R' [6 y1 n
]
9 b# Q) L& V. V) ?: M/ E. e- }( _7 C4 Z& H2 d( M
;; initialize the global variables that hold patch agentsets5 u: f2 d1 j- Z- K
set roads patches with9 w' M3 D7 a+ E. n( a" h; h, I
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% a+ k8 y6 E# p, O* D
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 o' B0 X0 r P( V" Z, `
set intersections roads with
' O* B+ d% U' V+ h8 j [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
' {9 @- Q: _& S0 @ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 m6 Y# u$ }3 {1 X# H8 B% l8 A8 e5 l! b1 f: p9 Q
ask roads [ set pcolor white ]
. H. c9 ?4 p, i5 Z$ P8 S+ Y2 u# | setup-intersections
0 \: ^2 L6 q, P" Y! G9 H( }: Zend0 X g3 G- u4 ]1 c
其中定义道路的句子,如下所示,是什么意思啊?
. H4 f5 S: E5 C- o( [ set roads patches with
+ A/ ^% |. A( S" Z [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
4 I/ ]2 C3 Y+ z0 {3 X. x) P (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
( h. C9 R, r. [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? |
|