|
|
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。
" Q( Y+ l7 L, M+ s% M6 {netlogo自带的social science--traffic grid这一例子当中,
! a1 E# D. Q0 t& l# b! k$ Qglobals, P. {3 E, I/ c3 C" _0 k
[
1 V, |- O7 L! o- v; R/ E5 j/ F grid-x-inc ;; the amount of patches in between two roads in the x direction
, l. P- g% I- k( q) I/ V% _& F grid-y-inc ;; the amount of patches in between two roads in the y direction: A- X A. b2 q0 ]; Y! n0 Y
acceleration ;; the constant that controls how much a car speeds up or slows down by if
6 q t1 Z% U7 j ;; it is to accelerate or decelerate
8 k* R5 x) u; T phase ;; keeps track of the phase
6 G: M. }/ D) ] g( v# Q num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure7 U2 B4 h- [% H `4 R! ~' j
current-light ;; the currently selected light; x6 t8 L+ t1 s5 ?: ?
' h0 G4 B& B7 w9 ^9 N ;; patch agentsets3 v: D/ z5 _. Z' L4 ^& f X
intersections ;; agentset containing the patches that are intersections; l0 Y( }1 C3 h4 n: `" `; z+ m
roads ;; agentset containing the patches that are roads
8 x* [& M; r& w& | n]2 q x: ~5 W0 v2 _" i7 {# ?: d
/ S2 _$ R" r/ }, P: `: O: `
turtles-own! h* o+ f& a9 a! \: p4 d4 J
[
8 f1 D p- W2 W+ ^8 U speed ;; the speed of the turtle* q9 r7 v: o4 B0 f0 ^% M
up-car? ;; true if the turtle moves downwards and false if it moves to the right7 N* t* w% `' N; x2 r& f
wait-time ;; the amount of time since the last time a turtle has moved% C/ m; C5 e$ Y# y& M8 k
]
: s! _- |" p' o
% z! b0 |% O' Z3 tpatches-own
6 l& m. i; z. ?* v" Z1 ? w[
6 v {& e* _* P5 }# c; L intersection? ;; true if the patch is at the intersection of two roads
. K' S# @; S, ~- [; y green-light-up? ;; true if the green light is above the intersection. otherwise, false. f* [0 R, L$ s V! ~6 f! C* S8 {
;; false for a non-intersection patches.
1 g, h, W) I1 _1 P3 i+ f my-row ;; the row of the intersection counting from the upper left corner of the
$ E+ T" y7 @7 R' r5 |7 v& A' B ;; world. -1 for non-intersection patches.7 J+ y2 x3 c$ m) H
my-column ;; the column of the intersection counting from the upper left corner of the
- J2 p s+ [- } D% c' `8 [ ;; world. -1 for non-intersection patches.
- N& ^' o% K# b6 N& c6 \ my-phase ;; the phase for the intersection. -1 for non-intersection patches." o" Z$ Z# z5 C& \
auto? ;; whether or not this intersection will switch automatically.
5 J* ~* p9 V/ X* [ k' I8 ` ;; false for non-intersection patches.2 V* n, |, w+ E
]
8 w4 f+ V* Y, E$ o
- p4 ^, O% m, T9 o, d
! b5 `) i6 B3 k! F' G;;;;;;;;;;;;;;;;;;;;;;* t5 G+ A0 Y! n |6 u) D+ ~8 z8 E
;; Setup Procedures ;;
. u3 h4 D* j% W/ g+ N2 C! H;;;;;;;;;;;;;;;;;;;;;;* H8 f8 Y+ D( y0 @
+ ]: o8 ~$ Q4 q% O, G8 c
;; Initialize the display by giving the global and patch variables initial values.
/ K; p; [7 x) E* U; k;; Create num-cars of turtles if there are enough road patches for one turtle to
) P! S6 [$ T0 u' T. d% t3 w$ c;; be created per road patch. Set up the plots.
$ u' e7 s5 H9 }& ito setup/ p9 @' S" F i, T& h
ca
! }0 j" O3 t8 R+ A2 O setup-globals$ S( T7 D2 I% [ ]
+ u" u0 \3 U3 R ;; First we ask the patches to draw themselves and set up a few variables: G1 w- U$ b& @
setup-patches
7 [' J ?- A. ^4 G1 k make-current one-of intersections0 p- ^7 ?- v& e2 F
label-current
2 G3 x/ c: b( e) h2 V" B f+ f# |( ]9 p# A
set-default-shape turtles "car"- X. r, X6 C. v4 F8 w$ ?1 o8 H
) n; P) I: _! S3 p5 @% C( f if (num-cars > count roads)5 |& j0 @- u/ e2 @
[+ E2 K/ P( z6 Y! i9 C
user-message (word "There are too many cars for the amount of "1 L+ ` A m6 d) g1 z/ D
"road. Either increase the amount of roads "
: Y: L, i1 {+ H% E) L* |& h "by increasing the GRID-SIZE-X or "6 D; N$ |$ x5 P/ a* _
"GRID-SIZE-Y sliders, or decrease the "
. H$ a6 g* v: |% F "number of cars by lowering the NUMBER slider.\n"4 V% \+ _: H) F& G w
"The setup has stopped.")
; B' L( P! V; `( n0 Q7 h stop
E. z* X* u* y ]
( H2 w8 R; ^. s0 \: g; ?( G9 S) g5 p! ]2 O7 l: e- [' u$ ^! L
;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color+ g- | c; R) K1 X) o
crt num-cars
) h- D6 s/ k1 \: e+ n [
$ p$ N1 z Y, K setup-cars+ @0 j* n) ]* z+ `; H
set-car-color
9 i# O1 I. T ^8 ~. F4 z record-data
+ E3 c+ \/ o4 f8 `6 y: F ]; s5 d$ U' l7 n( x) o
7 p; o2 Q4 g+ I ;; give the turtles an initial speed
8 S' X- P3 l+ K0 ^3 K# ^/ \" J8 D/ l2 G ask turtles [ set-car-speed ]
! h% B0 M6 X3 Q) j4 j
, M2 [5 t+ H( x/ x ?: Q$ E reset-ticks8 f e* r. P W
end
1 j, n; T! N5 [/ ~" P* n" p9 S# I' ^2 v6 g: m' Q7 T. v
;; Initialize the global variables to appropriate values
; h" D. V' S* T2 G; |$ r- Kto setup-globals
5 z, v5 H1 A; b6 Q set current-light nobody ;; just for now, since there are no lights yet
5 w7 G* Q+ [( B$ y l set phase 0* S, I& u) X7 A: E* ~
set num-cars-stopped 07 f& a8 _4 [/ o- n+ D$ R# {; Y
set grid-x-inc world-width / grid-size-x
6 t, U ^6 T. _. {8 z set grid-y-inc world-height / grid-size-y
, s* D$ z4 B4 g6 f
1 X$ s; _/ @3 n8 n ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
) C0 Y+ n9 f3 q, r! E N set acceleration 0.099
* n A4 ]1 c1 e& n5 Zend; b I! v( S/ d
! P5 b3 A! C' y4 b& h) D;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
+ C' [* w; m8 W0 @ t9 I0 T;; and initialize the traffic lights to one setting- m5 a+ a% b7 B
to setup-patches3 `0 v2 `% `* L" S7 [ c2 q9 `/ U
;; initialize the patch-owned variables and color the patches to a base-color
2 v) H% H8 _5 A& x% o. P! ` ask patches+ E2 g) P8 t( _: D
[
. ?4 r b6 ^" l! j7 R set intersection? false
P) c7 [& G; X: V M+ }3 u: q: D set auto? false
- I: L$ \& s; k set green-light-up? true
( Q/ x6 Y9 ]' V- i! u+ o set my-row -15 B4 h r7 u" w- [5 k( Z( e
set my-column -1! j9 n6 ? H3 G/ }0 @. `
set my-phase -11 f+ N' M, o) h- u0 ]
set pcolor brown + 3
' ^7 t2 T3 A5 r# f! V/ j4 _& \% o ]1 [) i* u2 p; K, h1 L
( ~- `0 D' ?: {; O; j ;; initialize the global variables that hold patch agentsets
! X' R4 A9 t' b3 x/ z4 _ a set roads patches with6 X- n) T1 P9 M! l! A
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or- x; c) s2 d4 x
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]( B! A8 Y) {- ~& K* ]) e4 }
set intersections roads with5 i2 T8 P8 h/ o1 }. V
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and+ K0 E$ N1 {& f2 O! l9 e8 [
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 B- k, ~" S1 z. r) x3 H
4 V+ T9 U! X+ f2 o% f ask roads [ set pcolor white ]5 ?+ C* |' ^; Y$ m: d
setup-intersections% M& }9 Z9 P3 D L4 G
end
* ?0 e# q; r4 v4 {! q其中定义道路的句子,如下所示,是什么意思啊?
# K# u" e# [/ D0 x+ Y set roads patches with
4 q: }' ~5 w3 G, v! Y2 W/ } [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
* R3 ^; d l+ A* K/ | (floor((pycor + max-pycor) mod grid-y-inc) = 0)]' A T E5 [. L) M* O
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? |
|