|
|
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。6 I9 }7 y( d; H/ L, D1 ]
netlogo自带的social science--traffic grid这一例子当中,
! ~! m, q6 \2 G) d& L3 _% h8 P$ l9 Jglobals
- q- P( e: `) Z9 P$ }/ ?) V[
7 @6 h7 W% i: @! e3 p: u grid-x-inc ;; the amount of patches in between two roads in the x direction' I7 ~" F$ F |/ r' F
grid-y-inc ;; the amount of patches in between two roads in the y direction
, U5 J U6 ^- e( ]8 U- V. I( c w acceleration ;; the constant that controls how much a car speeds up or slows down by if; R; W$ X, j( `- s
;; it is to accelerate or decelerate- V$ @/ c- m5 C# P* g) G
phase ;; keeps track of the phase& H- J& b; @2 ]
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
1 l2 j% h9 k" h current-light ;; the currently selected light
/ h' U# f5 t- A; G: C, c* A( d% G9 ]- O W6 T7 u
;; patch agentsets
5 X; ?6 C, T" ^- v intersections ;; agentset containing the patches that are intersections6 F0 e- q/ i% ?( A3 q
roads ;; agentset containing the patches that are roads
- y. ~ i1 m. ~% u9 @]
+ ~' P" I/ K1 K9 D' z0 I( Y, t2 b ]" b( E
turtles-own
6 D5 S1 I2 w* `+ H( O0 q; o1 p% g[9 f# J' g6 r- M. Q' Q
speed ;; the speed of the turtle1 Z; `0 L3 `& w7 }- W
up-car? ;; true if the turtle moves downwards and false if it moves to the right
3 H- X- L7 ?/ p Z- m wait-time ;; the amount of time since the last time a turtle has moved! b+ x5 |2 J- Z7 g, h1 W8 A
]
% `1 U. T7 S4 O; I' T$ _8 q9 o
: U. I; |8 T, e* u6 r: g8 i$ }patches-own
% E1 t3 c, B. B/ s' C4 s+ v[
. K2 ^/ n2 O8 }! ]: ~ intersection? ;; true if the patch is at the intersection of two roads
S# E- Q6 t, E& {0 f5 g3 Q green-light-up? ;; true if the green light is above the intersection. otherwise, false.1 M: m L( N' c1 W v9 r
;; false for a non-intersection patches.$ U R0 H, M' Q! n; l* P& |
my-row ;; the row of the intersection counting from the upper left corner of the
8 R, Z6 O3 d& w4 V# Y4 m) e' V ;; world. -1 for non-intersection patches.$ s i9 W% N+ G* ^+ L8 m
my-column ;; the column of the intersection counting from the upper left corner of the1 q) ~9 z2 D$ A! H; `9 y6 k
;; world. -1 for non-intersection patches.
& Z1 H1 {4 @+ H5 k my-phase ;; the phase for the intersection. -1 for non-intersection patches.
5 T3 o; E! l5 O8 E7 U auto? ;; whether or not this intersection will switch automatically.
* k+ Y0 d4 P+ l9 K: L" [* L5 S0 _ ;; false for non-intersection patches." @5 ~3 c' W/ f2 \8 e \: E
]/ v' _! @' S ^$ _( O. r+ ?
3 g, O# q |9 {6 p( u8 m4 i5 J
$ l0 H) |% ~1 L$ u: ?
;;;;;;;;;;;;;;;;;;;;;;4 U, c2 T% \1 b5 H; O* Y T2 w
;; Setup Procedures ;;* ?) G: B' J8 `1 ^
;;;;;;;;;;;;;;;;;;;;;;
; [! @8 w5 q2 u1 K; o! n. W0 y+ O: g1 v4 u" D3 }/ h
;; Initialize the display by giving the global and patch variables initial values.
2 \5 r7 R. z9 g& L;; Create num-cars of turtles if there are enough road patches for one turtle to
4 u( y- n/ m( F# ?;; be created per road patch. Set up the plots., ]# l% O2 U8 l* U
to setup* n4 e* t7 `) g
ca
( w% w( q9 w( V! }) ? setup-globals
2 O) J. X: |9 X0 o1 H
3 m3 U6 n9 @ [ ;; First we ask the patches to draw themselves and set up a few variables
: K* J. v# j- F1 @1 h& I setup-patches
6 v6 A$ n# Y. |2 A5 R7 T" D3 d* _: S make-current one-of intersections
' T1 g8 b9 ~' C# p label-current
/ ^: ^( p8 E4 I' D( P: W
* {3 i& p9 E# s! B6 n+ [: T set-default-shape turtles "car"- S% F. f8 V. Z' w
& b% ^, _1 k7 ^7 N
if (num-cars > count roads)
: q0 D! J/ U/ N/ g [0 i% v5 P8 Y7 o' \% e k: x
user-message (word "There are too many cars for the amount of "9 b1 t/ }+ H6 `
"road. Either increase the amount of roads "
1 @3 W7 Z7 I, x "by increasing the GRID-SIZE-X or "# s! O0 V# _% Q% ^
"GRID-SIZE-Y sliders, or decrease the "
6 l# i# g' b2 X' J "number of cars by lowering the NUMBER slider.\n"
8 q+ Q4 x! A+ ~2 }. G I "The setup has stopped.")
5 x4 n# z- q1 `0 ?! U+ W% P stop
- `9 o1 Y% B5 F" m ]
5 ]- V' W# w) J/ w( D5 H9 {
+ r* D$ ?5 h9 V0 ~, t" z; d& u ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color, z; Y0 r: w; s' O7 U. @( `
crt num-cars
3 R$ n: B. O$ w! O# F; ?! v( r [
; L( f4 Q$ {' w, o setup-cars, g) \8 q/ u A- v( Z# v
set-car-color
3 Y/ m' |. z$ w record-data
$ t4 g% p; Q6 m# ~+ I- w ]: ]8 H, ~' ~# p, k* T
$ |& ]: V9 [: s" }, K/ d ;; give the turtles an initial speed
! P0 D9 S, T, M* R) K6 Z ask turtles [ set-car-speed ]1 F# [- I" a, A, H J! b
! Z0 _8 z# c* K: Q! n$ W9 M
reset-ticks
- p1 I* G! J' N1 _% x8 ]+ kend' l* b/ t, @/ w5 v+ h
, E3 s$ d `1 N# v5 S( i;; Initialize the global variables to appropriate values
; V- f0 I4 @( _/ J. ?8 k0 ]$ _to setup-globals1 F+ v7 G+ h$ f# C& K4 M6 O
set current-light nobody ;; just for now, since there are no lights yet
' |' G* l' ^; N# X- q! u set phase 0
, D4 _4 _- `0 N! j/ J set num-cars-stopped 0- C9 V; b6 C0 s- M( ~
set grid-x-inc world-width / grid-size-x Z" j) u, i9 m, u- X
set grid-y-inc world-height / grid-size-y
9 N& c% e' c$ Z8 G1 z- ]% b( S# J* k" L% d8 s
;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary7 G9 r# s& ]; n% |% K3 ~. M
set acceleration 0.099
" Z( D, C1 s' aend7 b1 p3 O$ F! T F* Y& o
0 j+ @" }! z/ ]2 T0 e; c1 c3 e
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
# S: J3 e& b; ?) d$ B;; and initialize the traffic lights to one setting
4 a/ E0 D" _) E1 o* H( A% Eto setup-patches
- q1 w0 }% u3 H: A. B ;; initialize the patch-owned variables and color the patches to a base-color9 z# _: ]) b! {$ |. I* O
ask patches
( A6 j& c: D. d [5 i3 v* j) W* ^: d! G" @
set intersection? false' u, N9 Q2 N2 `7 W* g
set auto? false4 ^! W. A, |* y/ k
set green-light-up? true: j( D) E/ i) O+ t) {, [
set my-row -1
% n7 i% n! S& E$ a" G V set my-column -1! O( m, x: g3 ~7 O+ w y: D7 b* E
set my-phase -1
6 x D- i' f" D; z/ ? set pcolor brown + 3! C. Z+ @ M( U0 v) m
]
: S' @4 [! i% D0 x6 h- U+ @+ u" U- ?7 e, w' q
;; initialize the global variables that hold patch agentsets
# ? X% F, ^4 m4 D set roads patches with l* ~0 P% I) l; \" O, J: H8 L" p+ y
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or- E: K% U1 |/ H: E) T5 i4 ]6 J1 a8 o
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
+ l; v: P$ [: \3 y' |! n8 D3 e5 d set intersections roads with7 r& ?/ U0 I6 |) ?6 q7 P. d. |
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and, D6 I% C7 j/ N
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ n. H2 w2 S9 y7 T/ {
5 s+ P0 A4 k- A+ E% q* x ask roads [ set pcolor white ]6 `6 F% l1 R3 W! W
setup-intersections# w+ i+ T& h: z
end; a9 x* [3 t+ ?4 _: V5 Y. n
其中定义道路的句子,如下所示,是什么意思啊?, \' g8 ]% x- K+ t* `9 z- e V% G
set roads patches with
+ w1 J: q- k8 p [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 ~; ?! `! E# f; X (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 s9 d' @, F5 F/ f* }# {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? |
|