|
|
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。. Q2 Z5 M: T0 M5 {2 s% K& E
netlogo自带的social science--traffic grid这一例子当中,
, V+ l% Z: o0 l; Sglobals
8 y8 x V1 G# |7 S& g& m7 X[
% ^) q v* _1 ^9 { grid-x-inc ;; the amount of patches in between two roads in the x direction+ a! Q! S3 ]' F- ^1 x
grid-y-inc ;; the amount of patches in between two roads in the y direction! a7 D( y3 i& r
acceleration ;; the constant that controls how much a car speeds up or slows down by if
8 `! k0 I# h; x# o- I ;; it is to accelerate or decelerate2 H; s$ {+ n% V6 r* P
phase ;; keeps track of the phase
d; a. V) |/ j9 \* ]& c4 J num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
8 E/ r" I) v, v current-light ;; the currently selected light, T7 E# w. |/ J* c# q
; h) [4 M) {1 b! B8 Z! z, ]+ C ;; patch agentsets
; F3 I9 w+ J$ K3 }, ?: l intersections ;; agentset containing the patches that are intersections
! U2 X9 A" F/ d6 Y/ b* h roads ;; agentset containing the patches that are roads
: | F& n# D* R3 e0 O5 D]& a' F# R8 U( p' X% w! h( v
0 j6 C) a! V4 O6 J: v3 P5 fturtles-own
& k6 r7 E6 {. n7 F[
# m7 k% z8 z4 z1 c7 z4 {, E! K speed ;; the speed of the turtle
5 u% C4 C8 \# G% O8 A" ~9 O up-car? ;; true if the turtle moves downwards and false if it moves to the right2 K- n" b1 C& j8 N" k" g
wait-time ;; the amount of time since the last time a turtle has moved
. Z2 g/ S% W; G' w$ J r8 t]
3 T+ C( q2 m& w& g& L
5 }& x' u' J8 }9 i7 {' G+ c: [patches-own; P! F ~& s' e1 l1 F9 L' A- ]
[# _3 T; u+ W/ j5 l2 J" o& I
intersection? ;; true if the patch is at the intersection of two roads
- [/ C5 D! @& S) n green-light-up? ;; true if the green light is above the intersection. otherwise, false.
, y# k8 j [. G' H" b* U ;; false for a non-intersection patches.
9 o7 G( s- L m8 G my-row ;; the row of the intersection counting from the upper left corner of the
2 y5 ]; N; P. k* P& U7 \ ;; world. -1 for non-intersection patches.
7 G! m n. h( K; i my-column ;; the column of the intersection counting from the upper left corner of the/ e' E" _" z* _/ P7 `
;; world. -1 for non-intersection patches.* N' t5 s# n5 X) `" `1 b# w
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
: q; T( Y% N& R$ O. F auto? ;; whether or not this intersection will switch automatically.5 C: S9 V1 O5 \
;; false for non-intersection patches.
9 C: w1 f3 p; w# {- r]7 G* y. _: H' [9 O; |% d1 h5 r9 p
3 e- [& f- n8 ^' z
7 q Z( W1 y$ u;;;;;;;;;;;;;;;;;;;;;;7 m o: G! V; m$ w* n4 O5 ~& C
;; Setup Procedures ;;
+ }) e0 y ]2 Y" S4 u;;;;;;;;;;;;;;;;;;;;;;2 S) t$ M' {2 A) e3 q
8 y/ F) S% k4 ~; c/ m
;; Initialize the display by giving the global and patch variables initial values.
% S+ H# |: `9 g q;; Create num-cars of turtles if there are enough road patches for one turtle to
. t! b( r4 Y& A3 T+ B1 v;; be created per road patch. Set up the plots.1 i4 p/ v- z9 ?) a3 H
to setup
) x6 _; G* S" d1 J8 X: b ca
\" M/ D+ [1 C5 n3 y setup-globals
6 p- h o& Q6 _' [+ Y! R0 ?; E& o1 [0 G
;; First we ask the patches to draw themselves and set up a few variables
( [$ n' [" I" R1 c5 ~4 a5 z4 D$ K setup-patches
4 U {) ]- _# b0 E5 Z make-current one-of intersections9 B0 s0 g- e3 t1 |
label-current9 H/ g& N7 |: j2 D( O
* X% V1 R o0 I# E! V+ m0 f set-default-shape turtles "car"
, N: c1 { T, l+ K/ O) m @5 c% P
, G" G* }% f4 |' }+ w0 i if (num-cars > count roads). `8 n2 F: e1 |4 q+ E& \
[
2 Z- r7 U1 u# M \ user-message (word "There are too many cars for the amount of "* O6 }- ~! m: }& I& v8 o
"road. Either increase the amount of roads "2 d% ]8 b8 J( t! ]
"by increasing the GRID-SIZE-X or "- {. S# k; v3 @: V( t" p
"GRID-SIZE-Y sliders, or decrease the "
& k$ m4 r4 [8 o! k6 h "number of cars by lowering the NUMBER slider.\n"
/ z* m7 x- Z+ a4 h "The setup has stopped.")9 n! Z! v1 n9 a- Z' b
stop7 f4 J- k$ h2 e7 e7 y& U) P
]
0 r& D8 Y" h6 t5 N9 o+ ]' `* @9 w
( }; A/ u" w* z- i# M ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
- b, |0 F Q% t# D/ m5 n crt num-cars3 E& Z6 U) @: {% m+ o: }4 S) _' V" x# s
[
% f0 O. M) t! V S" e setup-cars
# O p0 ]2 m- { set-car-color
, y1 O a! U6 {% W- m& I2 R record-data# {4 B2 ?. L6 b( r1 r' g
]* ^% X% _0 _' ?. @/ ]( S: F! r
5 d# i8 o7 ?2 ~! V! ~ m% _; d' u) ? ;; give the turtles an initial speed
9 A& W9 G, }7 x. G. J' k, X ask turtles [ set-car-speed ]: K, A2 E. B6 r/ b7 s! W
/ Z3 ]/ k7 m- G: x' I3 O* C$ F( Y
reset-ticks
1 W, M& B9 t) Bend
I/ d5 K( n* n. F3 x. A D9 A, S
, W5 I$ \% f: U2 R6 F;; Initialize the global variables to appropriate values( ^3 R" @: G+ S' p" l Y7 Z) p
to setup-globals, D/ V; r% h2 ]7 B" R5 D
set current-light nobody ;; just for now, since there are no lights yet& B( U/ D4 R. V/ j9 Y1 x+ S
set phase 0
! U D4 Q9 P8 y% o# h( }. l8 ^ set num-cars-stopped 0
2 t; u2 v; s: t3 n, S9 n2 G& r% C set grid-x-inc world-width / grid-size-x
0 Y5 y/ K+ a! a" Y) G7 ?% g set grid-y-inc world-height / grid-size-y5 A$ Y, F# r: e& k7 c* \2 e
/ v- X) V. B5 G+ A3 u" A$ A ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
1 m' K. g$ M+ ~ set acceleration 0.099
& t# ~% Q% \7 @/ j! y3 M& J, Mend) C( C/ J5 c. J$ f- a
1 j2 h: |, K, W) [
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,& p1 g8 a" a, t
;; and initialize the traffic lights to one setting0 q' F: r3 n$ s/ M4 ?1 L
to setup-patches* g) G* P) n6 f$ [; U
;; initialize the patch-owned variables and color the patches to a base-color
* y" J3 \- H0 O ask patches
1 \ U) j: j6 F; J! a9 o [, |! N7 B. o2 t- [& x+ @% v- X
set intersection? false, t& h% K1 d; f4 _5 @
set auto? false
* K1 G" l( v% o' y3 R set green-light-up? true
' B# i6 H8 s6 Q7 M- b set my-row -1
; J" J) h; o$ s( i5 x5 J9 P' B r! y set my-column -11 g$ u0 Z2 X+ ?1 O" @" |. n+ }
set my-phase -1
; ^. g* Q3 Q( K& r/ q set pcolor brown + 31 |9 m8 k& P; y" E- s" e, l" H
]
\+ s) O9 J$ {1 g v$ h( J4 C& p! I. f. M3 f9 v
;; initialize the global variables that hold patch agentsets$ e- v5 \/ J( ]7 f4 J
set roads patches with
& j W* m, L$ q8 S# u! f [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
Z$ L: @8 G; Y9 g (floor((pycor + max-pycor) mod grid-y-inc) = 0)]% y# R3 u) ]) P8 d; e5 k
set intersections roads with
% ?% Q, X) v7 ~4 R4 L" N: E0 u [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and$ z& X' E8 k7 a7 _
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
j; r- ]* {, }) H2 ^& Z6 q O5 ^( d# E$ P
ask roads [ set pcolor white ]" O% S. n) c8 \ Z9 k0 }% ~( {! v
setup-intersections
% x9 A/ i) ?2 C0 h# J8 k% Q0 O) y) J' uend8 A1 Q' ^( k( [- r- Z l
其中定义道路的句子,如下所示,是什么意思啊?9 @! }1 r4 C' S' ?
set roads patches with' a$ o, S# A) q h8 r
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or# l/ F& i4 n! I. K
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) M. z0 |2 f* V8 |! d) K4 ?3 `" [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? |
|