|
|
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。. u C% r( _* w
netlogo自带的social science--traffic grid这一例子当中,* c2 j3 w' I' j. h, {2 H% @+ H X
globals
/ d# P/ Q( L' h3 e9 A' Q[
1 V. X- L6 X& k$ N( { grid-x-inc ;; the amount of patches in between two roads in the x direction
' _( l' g3 d- w" `# H& D# o! D grid-y-inc ;; the amount of patches in between two roads in the y direction
8 x8 q8 a* x# C8 D* T/ i- r2 m; l: Y- Z acceleration ;; the constant that controls how much a car speeds up or slows down by if5 c8 H$ v) `, p& j; x- p; ^+ w. h
;; it is to accelerate or decelerate
+ J, @9 Y* z/ v/ S+ e7 E8 _. X; J phase ;; keeps track of the phase I1 I! S# m( d1 Q$ T
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure, Q' v* n3 @! H3 r6 Z
current-light ;; the currently selected light
, F. L) m% E* y
T3 @2 `! ]7 ~" @ ;; patch agentsets
. I+ y- ^: _0 B) R intersections ;; agentset containing the patches that are intersections
# }4 s+ i3 e7 G2 ~ roads ;; agentset containing the patches that are roads
( W z- W- a# u* o9 R; B2 O$ K/ []- ^. n3 j, h! w7 C; S" s& Y" p0 P
" [2 ?' u. A# D& r6 o4 aturtles-own
: u3 l. H! g s7 i6 P; ~[
* ]2 q! F4 ^! f speed ;; the speed of the turtle" ^# B3 G% H9 P2 C' E1 A' ^6 L# I
up-car? ;; true if the turtle moves downwards and false if it moves to the right. k' M9 |. `+ a* N
wait-time ;; the amount of time since the last time a turtle has moved
3 r7 q7 O, R* L' X; l' m5 Z) W7 l% n]) J' ^* {" {) Y+ q
2 K. e) _( q; D8 H2 M6 K
patches-own: L0 d0 o* x r
[6 y7 t) u+ }" X$ A# R- H6 V( d8 k
intersection? ;; true if the patch is at the intersection of two roads d6 q$ y" Y2 q3 O- W6 i, k
green-light-up? ;; true if the green light is above the intersection. otherwise, false.! J" [0 A: g3 x9 M
;; false for a non-intersection patches.* ?7 j. c8 N: s5 f4 o* b# e, p
my-row ;; the row of the intersection counting from the upper left corner of the
' F! f( } T" u. c ;; world. -1 for non-intersection patches.
5 g( k; v& O% M, k+ y: z' r3 y my-column ;; the column of the intersection counting from the upper left corner of the, i- f! _. x! m( p, ~* G
;; world. -1 for non-intersection patches.- I5 S0 ~' l: J* p; e3 A
my-phase ;; the phase for the intersection. -1 for non-intersection patches.& w" W4 h1 L# ?
auto? ;; whether or not this intersection will switch automatically.9 O! W. j4 D0 d5 ~ X3 t1 h
;; false for non-intersection patches.
+ O9 U9 h4 e7 R( V]
; e: G0 s1 f9 X3 h- \# l) [. N0 a) ]: C) X- C
; y, e* r% p+ ^1 Y3 R) K+ c;;;;;;;;;;;;;;;;;;;;;;/ i0 Y8 C4 {/ V
;; Setup Procedures ;;
' P' e% W: A: l* P& {;;;;;;;;;;;;;;;;;;;;;;! U5 b' ]: d1 [- ~9 b
2 X- S3 F5 T8 L;; Initialize the display by giving the global and patch variables initial values.; e7 w* B* i, l# ?& k6 r" c
;; Create num-cars of turtles if there are enough road patches for one turtle to
8 S T9 A6 {; u;; be created per road patch. Set up the plots., y) E2 @' H0 N+ N( D5 [4 j9 a+ n
to setup
8 I7 m9 L2 Z$ {* u8 V" t ca
; t# ~2 V- l3 s% W y6 w setup-globals
$ X* E- L" m. e/ ?( `) V- d/ ~% l) f) {4 l1 P! m: G
;; First we ask the patches to draw themselves and set up a few variables5 l+ y I" f. G
setup-patches
; _) o4 O; p( T1 i& O" f+ X make-current one-of intersections; L! @8 J+ l. X( g/ ?: h
label-current. q- }1 z6 C5 v: J
0 E9 K# z& e5 U7 e set-default-shape turtles "car"
i% l/ c6 {& G# I$ ^6 x" x5 Y; v% o8 T- \: o
if (num-cars > count roads)
" D, \1 P! }+ D( L [) [) N" {$ E5 ^
user-message (word "There are too many cars for the amount of "( {" l1 N$ {- z# K# y+ z& `
"road. Either increase the amount of roads "& d6 j7 P0 g J0 T. y! q3 T' ^
"by increasing the GRID-SIZE-X or "- T" F3 m Q1 E$ m( C4 H
"GRID-SIZE-Y sliders, or decrease the "$ k) A8 V0 X8 y: A' ]# |$ d6 j
"number of cars by lowering the NUMBER slider.\n"
7 p/ n- I" a: A* q1 y# m# k) C "The setup has stopped.")
6 v& _9 o% q. G7 H stop* O3 U! o- R) A) c6 B" \6 \
]
( o7 G& A) r" B, j5 C0 j9 g3 x: J" {; ?; f2 [1 ?
;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color) I6 N" u0 O2 V+ u
crt num-cars8 s4 G% q p$ a* \2 Q5 e$ f2 r1 i
[ `0 L4 G) k& @" {. X
setup-cars
0 T( G3 D% L6 w8 u# t6 u( o, ? set-car-color+ R' H4 e- \; m6 a8 t7 @3 L2 n( Z
record-data
% j( b* {5 z; t" Q& i/ E ]" E! {. T9 ?& k8 j
3 ^( H" D) l, c! n5 j! b ;; give the turtles an initial speed
8 n0 U9 E: Q& D0 _ ask turtles [ set-car-speed ]$ Y0 v* f5 }/ m' K
" f( E7 `' A, f( A/ \
reset-ticks
0 |# i3 a; p; {6 E) m7 `end
0 d, i3 M' M# o0 v3 I$ r( `3 j p+ Y& r( I7 l! X* Z8 m+ S
;; Initialize the global variables to appropriate values$ F* z# x, K8 o1 S
to setup-globals9 [4 t, d; P5 c1 O7 X
set current-light nobody ;; just for now, since there are no lights yet
" H4 M8 [' m: D: W5 n7 `# a r5 ] set phase 09 v0 z" z0 P8 V& U9 s
set num-cars-stopped 0( S @: O& X; L* b7 g
set grid-x-inc world-width / grid-size-x" P; P6 _! a, Y. i' q! N! ~+ Z
set grid-y-inc world-height / grid-size-y
; v5 }! w! w/ g8 `8 F& D! J+ K4 f. M7 Z. B O
;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary6 a. K- K2 I0 F- o
set acceleration 0.099
8 |* j3 ^) U7 `- ?# b" n0 iend
% a" g( y3 ]! I) _5 ]7 ^; z {. K8 H3 k" Q3 `2 h j3 ]
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
1 T' M* Q. I8 j* N: u4 v;; and initialize the traffic lights to one setting& K( k, c( \( n7 j& B' {- [: d
to setup-patches, r; g, h. F* i8 \6 C! A; q
;; initialize the patch-owned variables and color the patches to a base-color% Z% @' i$ x& S% g+ u( j9 d. Y
ask patches$ H) a ?% g7 P2 c8 C
[0 y0 C& D$ }0 o% f1 I
set intersection? false4 c' S3 C: ~/ U4 \' i! H
set auto? false
( s& `2 Z& P& I- T2 ]1 M8 [ set green-light-up? true
8 l/ o: }8 }) J7 b$ g" r set my-row -1
( f j, n$ C: _. E2 n! v9 A set my-column -1" }! x& p, l3 [6 d/ {1 o% p
set my-phase -1/ s$ }2 ~3 C5 n* L+ U
set pcolor brown + 3
2 ~0 I8 }# b/ [, a1 K. t3 ^ ]; N% C9 s9 W; ~! o" {1 g
+ t. i6 k+ j! n W9 z1 ~" x* g ;; initialize the global variables that hold patch agentsets* W! q1 ^. i- p6 V$ k# l+ ^5 { a
set roads patches with
" Y9 q' n' E& J9 q. r [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 l/ h- V9 T/ k# Z8 z! X (floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ u! P9 a% W3 A; b+ d
set intersections roads with/ g- d6 c, |4 s: S
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and, g( U: T& {$ S( `0 ~7 Y# |) u
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]; K5 g' N0 ?* b* J# \0 i9 w
K. i) x' L3 |7 w
ask roads [ set pcolor white ]' O4 {" D5 T- z8 {: Y0 R/ L7 c4 d0 B
setup-intersections: J S& K e& q7 i% @( }. o% M
end6 X% K3 _/ Y3 P. |8 ~
其中定义道路的句子,如下所示,是什么意思啊? g8 W# A! y2 i1 y8 w* X
set roads patches with( r, n7 a X* @
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or, g0 B1 F2 R- j( @: X
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
" f" K/ c8 Q2 _# `, X* b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? |
|