|
|
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。5 H6 l, F+ r. E( U3 h0 R
netlogo自带的social science--traffic grid这一例子当中,
8 M6 G( P4 m8 K" i8 g; Pglobals
2 y2 L3 t; [* I) r0 {% y. |[8 F V2 c* n0 u5 S6 `4 |& \4 f& ^" E8 D
grid-x-inc ;; the amount of patches in between two roads in the x direction
8 I7 R- j9 F9 F: f$ A grid-y-inc ;; the amount of patches in between two roads in the y direction1 g; m/ @7 R+ Z( ]( l/ D
acceleration ;; the constant that controls how much a car speeds up or slows down by if
1 u+ Q( H+ J# z ;; it is to accelerate or decelerate) q& w" x# j& B* q y
phase ;; keeps track of the phase" F7 R( i$ P. l: C8 B
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure9 v' E* E. J4 J
current-light ;; the currently selected light# a c* f7 _) Z1 _5 x) |' i* m4 h
; p- `; f+ B; V; `' t( h$ e! b- c
;; patch agentsets
1 f& U7 h5 v+ j9 U! O& i intersections ;; agentset containing the patches that are intersections
1 D% ]# }7 [5 g/ j: D roads ;; agentset containing the patches that are roads2 v, Z9 s" b) Q/ B! h: s
]7 S( D9 q* s5 ^1 t" x3 O7 N, S
4 @; p4 \* J# M
turtles-own/ N3 B, g9 L! d; w4 l
[
! @. U1 t: n! C# d( N2 K, D speed ;; the speed of the turtle( I! B6 z# A5 y- h
up-car? ;; true if the turtle moves downwards and false if it moves to the right
" {$ i/ m. i3 { R. G; ^7 G' V wait-time ;; the amount of time since the last time a turtle has moved0 w3 w; e2 d/ e) h9 g
]
+ B' w1 U) V+ w+ H; y) U1 W& ^3 h- {9 v1 Z
patches-own+ k) ~* e6 n7 S* U& L
[
$ \9 O% e; U; _" G7 K3 I intersection? ;; true if the patch is at the intersection of two roads
9 M, l. X4 }8 _# _8 P green-light-up? ;; true if the green light is above the intersection. otherwise, false.
; k K# d' l9 l' {; \ ;; false for a non-intersection patches.
8 b- E4 v* e0 O5 v3 f my-row ;; the row of the intersection counting from the upper left corner of the
! g6 J B- F* i% Q7 s1 p ;; world. -1 for non-intersection patches.' m6 P5 }8 L- t8 O! B Y* M, A, B x
my-column ;; the column of the intersection counting from the upper left corner of the
& G& y: ` c! s1 v ;; world. -1 for non-intersection patches.
: @; s6 ^ o+ W1 } K& V my-phase ;; the phase for the intersection. -1 for non-intersection patches. Y! {/ O5 i- J# [( N" V
auto? ;; whether or not this intersection will switch automatically.1 z5 L* F$ I- D5 Z
;; false for non-intersection patches.
3 j% M$ T6 Q& U' r9 ]. m]% p/ c! i1 Y0 j4 }+ c8 X
$ J; _5 I0 y$ c5 R
0 u4 \8 H x7 ~& q7 {;;;;;;;;;;;;;;;;;;;;;;
- Q4 R% g. p% _8 w( r+ X;; Setup Procedures ;;
5 L C' {1 `* Z6 y' n;;;;;;;;;;;;;;;;;;;;;;9 M/ F% k4 _( e( Z. h
) W/ j) z3 q* b! n: V& k2 M( @! g
;; Initialize the display by giving the global and patch variables initial values.
) m3 J0 ]6 D; N9 p;; Create num-cars of turtles if there are enough road patches for one turtle to
9 v# |/ }! J$ v5 e/ p/ C) u- L;; be created per road patch. Set up the plots.
- ^2 ^: @# Z9 l5 oto setup# b# o5 l0 [$ w, k8 b
ca
- k J& |. D3 J1 _% V' P0 p6 D setup-globals" V# B) b2 F9 r- O
/ M, {$ ?: O6 E8 I6 M1 h, t) o ;; First we ask the patches to draw themselves and set up a few variables
3 E) Q/ W% I7 v8 D/ K" L+ ~, E setup-patches. M. Z; [ u$ I7 H
make-current one-of intersections
O$ S0 g. A9 z! j! G0 O label-current# N" q+ T( `' u3 q5 g. M
4 O0 @6 P. I% Q
set-default-shape turtles "car"
. K' S! p: S2 I3 [2 K8 H' U( p) S8 ~0 Q) m: E4 V' J7 b
if (num-cars > count roads)
+ Y6 K0 v7 ?+ E& A7 ]1 W0 H1 _ [4 l* w( [0 w" F
user-message (word "There are too many cars for the amount of "7 P8 `! G) ]; g9 t' a
"road. Either increase the amount of roads "; }6 }# ~6 O9 s& t- D
"by increasing the GRID-SIZE-X or "8 j. e$ O2 m8 s$ M( E
"GRID-SIZE-Y sliders, or decrease the "
( H% p; |0 C: U2 g9 j2 K "number of cars by lowering the NUMBER slider.\n"
( ]/ _# U; A3 ^/ r2 @ "The setup has stopped.")
; g) V/ \2 a9 C6 I stop
: A$ V" A2 @- g- i6 m ]
- u/ c6 A' G6 O& I5 w8 W4 c' q- Z1 y7 O# e1 t" @1 c
;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color3 a; c) z" G1 ?9 T9 y0 T+ U
crt num-cars
# h& `! T( ?) Q( V& ] [
8 J; @/ C1 R; e9 k& n/ S: \ setup-cars, @" t) E* t) d# ~
set-car-color
5 @1 V. o0 L; D# k: m% e7 i record-data
2 ^. W; p! F* P6 y* {- ]" R+ \ ]8 F a3 w, H& b! }" T: L% d/ Z5 t% w
! p& ^( _: K" D ~" a& o4 [ ;; give the turtles an initial speed7 d, }( g( s) J1 g
ask turtles [ set-car-speed ]
: U+ X* j6 Z2 S; A8 [9 [! _& g" ]# x4 l
reset-ticks$ H! ^9 f" G9 _, Z8 k9 G( I/ t
end
6 S% M# z( O& m7 M( N' F5 D: I0 c. Z; h! I4 W3 d
;; Initialize the global variables to appropriate values+ `* d7 f4 @% ^0 O. t
to setup-globals: ?% _: r! r9 n+ R/ d
set current-light nobody ;; just for now, since there are no lights yet* J( t: o# p( n" s
set phase 0
: M4 b* ~7 c8 Z2 q set num-cars-stopped 03 R( k2 f' _4 |. a, e! Z- e0 d
set grid-x-inc world-width / grid-size-x0 c" ~: j7 {( \, s- p
set grid-y-inc world-height / grid-size-y
4 C5 |2 c5 b& C) B
1 A7 e& T6 _5 q$ e! |# o ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
1 o+ _ O6 O& v' ~" t set acceleration 0.099
! ?7 L# |$ c* `% Hend1 z9 u4 k# H8 Q5 C
7 R( i9 c9 u( }5 `$ z/ V$ F+ {. i
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
5 e$ R) g( A8 b' ^1 F* w;; and initialize the traffic lights to one setting
+ f. ]. [) p7 m# ~to setup-patches
9 g! x) x/ p0 m8 A8 R4 W) H ;; initialize the patch-owned variables and color the patches to a base-color
$ X) q! m) [' V5 U* E ask patches4 J9 x# M& ~. H' N! w4 \
[
* G& e {6 n- S! ^; m. y* L set intersection? false
1 |9 I' Q( E7 n$ |, g+ `* i# S9 M set auto? false
; ^- M6 g6 ]7 y9 S+ U set green-light-up? true
0 w+ M" j W& _* x! } set my-row -1
2 `* a! u1 A- H8 o% g4 t. P set my-column -1& o3 @5 j- f, L" {( k
set my-phase -12 {& }; n4 ?, X$ M. q
set pcolor brown + 3
* T2 g" D8 a4 t8 C+ { ]6 H- _% l+ B8 Q3 `# K8 }8 Z
3 b# X8 B5 b6 V# z' B: [ ;; initialize the global variables that hold patch agentsets
2 r7 A( N: [2 `, a3 o) F5 g( k1 | set roads patches with
7 P" T+ a4 F' Q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
3 j: }5 [+ e# O& ]) ^ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 E. ?8 a0 k( S2 e% d
set intersections roads with" B2 W- N' y0 B0 R9 I; w
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
- i) M# f0 G4 C7 P4 c+ g+ t9 d% D (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
( E: h ^5 `$ s0 X* Q
9 ]& A A0 ~' y ask roads [ set pcolor white ]) b5 \# X# B2 k9 |7 R/ p+ K/ P
setup-intersections
$ |# s6 Q: }! y! |' Zend x+ i9 S" s4 i" E) J5 @, T
其中定义道路的句子,如下所示,是什么意思啊?
! f$ g. J( o, b' D set roads patches with
) I) @# Y6 i$ v) v: @! t& R9 v [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or. b0 ^ v/ D- `- a8 c* x
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 o3 A( q5 i# f1 H
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? |
|