|
|
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。
# y+ ~- O* c/ y5 `; Y" @netlogo自带的social science--traffic grid这一例子当中,% P7 J3 ^- ^' g' n- n
globals: C4 r0 v) G. ^" `
[
* Q! Z4 ~5 E* Y grid-x-inc ;; the amount of patches in between two roads in the x direction
& S) ^/ {# N: \; j' N grid-y-inc ;; the amount of patches in between two roads in the y direction
! w9 F2 F; I' E) U acceleration ;; the constant that controls how much a car speeds up or slows down by if$ b0 W# a1 [+ s; b# ~9 }( B. g
;; it is to accelerate or decelerate& L4 O: l8 m! d/ L# W' }
phase ;; keeps track of the phase
* L0 h! D4 C3 t7 e* T/ p num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
8 l; o s6 a8 q( B* B& h9 h" j current-light ;; the currently selected light
, F0 X0 U6 R8 S/ U1 l
; k+ D+ R( R/ v3 C ;; patch agentsets
8 E* a% H: N* n; w2 h; ~* D. y; ^ intersections ;; agentset containing the patches that are intersections. K# w) M# h; U' H1 W
roads ;; agentset containing the patches that are roads0 D) F' t( @% f
]
( a6 y3 o% T( v) ^' V' w8 y$ p% t* y: a# {) @; a5 R
turtles-own
; |0 R/ {% {8 s[- n( m, r% P/ M- A, R
speed ;; the speed of the turtle( ?* _/ w5 M7 _) X, D0 s! I
up-car? ;; true if the turtle moves downwards and false if it moves to the right
/ i1 Q- p% \/ |: |% I: V9 W2 e0 r2 {! E wait-time ;; the amount of time since the last time a turtle has moved+ ^1 @9 l' R7 e) p' d' x
]
+ {. ^8 z/ N) S3 z3 u/ W& e# Y Q8 r# R" S2 W/ A- e- [
patches-own9 s! H0 }7 N/ Z @) |+ t; c
[
/ Q, V" {: S. R% b+ ~% Z4 u intersection? ;; true if the patch is at the intersection of two roads2 Z! n0 @1 Z- {% c1 F6 G6 H- S
green-light-up? ;; true if the green light is above the intersection. otherwise, false.) r. D$ g7 k7 E; X* x
;; false for a non-intersection patches., n0 ?& `6 x2 A: ^* n) `2 l
my-row ;; the row of the intersection counting from the upper left corner of the
( L' s- d: T+ m7 [: H" F ;; world. -1 for non-intersection patches.+ |: O% p# Y9 h2 c+ E
my-column ;; the column of the intersection counting from the upper left corner of the
7 j8 p% z' }: s9 u: h ;; world. -1 for non-intersection patches.
3 {) b/ b& v' b; x8 F6 f3 y my-phase ;; the phase for the intersection. -1 for non-intersection patches.
. H- \3 N' Q0 T* I* Q* q3 @9 S auto? ;; whether or not this intersection will switch automatically.
. M0 `' ?2 W$ [4 u ;; false for non-intersection patches.
, p6 ]2 t1 ^4 U+ j]
7 w, q4 [5 D3 C1 N4 C& ?* q$ G
- B) t. Q7 X# }9 Z- Q6 w* v ^3 y1 x+ _
;;;;;;;;;;;;;;;;;;;;;;
' o6 p! S/ Q% \8 Q% I;; Setup Procedures ;;. S2 `' w" y( y6 C
;;;;;;;;;;;;;;;;;;;;;;
0 W; C+ y5 p! {, ~% h8 k8 j2 q- j
! I9 a% X7 ]* M b3 @) x;; Initialize the display by giving the global and patch variables initial values.
- D' ^3 x1 g" D/ U8 j;; Create num-cars of turtles if there are enough road patches for one turtle to
* l9 v* ? b S3 w `6 N# {0 w;; be created per road patch. Set up the plots.) [3 Y+ E* O8 @: r1 c
to setup( Q$ L2 t! T; B4 F- d$ r
ca
& ?7 R# P! u+ _1 u& t2 v$ ` setup-globals" X# |" O. E, @( b/ q: j" l
: \2 ?- J- t5 ^7 J- h/ e ;; First we ask the patches to draw themselves and set up a few variables/ _& C5 p( q* v* y- x1 W& j6 i
setup-patches* B" N8 U3 W# n1 e2 Q. N
make-current one-of intersections
6 {$ ~, S6 |# i- z label-current
/ z4 C* z2 f- W8 {1 H T; D& F* ]& L u, P
set-default-shape turtles "car"
) G6 Z X. e) D( V$ X z* o5 ?- V4 R7 g
if (num-cars > count roads)8 |+ Y" h- t4 k
[* b- y4 L1 Q6 f/ D* d! Z- }
user-message (word "There are too many cars for the amount of "% ]) H% `: v6 u' P0 a
"road. Either increase the amount of roads "
) D8 u( m# v, l( H "by increasing the GRID-SIZE-X or "
/ T, |5 T# t7 w5 ?) G, z "GRID-SIZE-Y sliders, or decrease the "
5 B9 ` G7 E$ H0 D "number of cars by lowering the NUMBER slider.\n"! y* G) q% j$ p$ j: Q' N9 z* C
"The setup has stopped.")0 I$ J7 o4 R9 r* S
stop; r- r2 l8 Q, ?4 f& ]9 R- r
]2 n6 @+ E& m1 r' J2 U7 L
) U" F5 N1 ~3 w' r" d
;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color2 I0 `" B6 Q1 Z, Q0 S8 {& L
crt num-cars5 F, D' J# D% d3 l# H( \
[5 L o! o1 W: }/ D" J8 P
setup-cars* m* E r' ]4 C8 R& n
set-car-color
* j0 y& N+ P" S7 R( p' J7 b" u record-data
$ N- O1 I1 `/ e" x ]
1 k2 h7 {$ W' P, w _" }! j; F% B. y' v$ Q/ v
;; give the turtles an initial speed
: _7 y; a3 B) s9 w( E ask turtles [ set-car-speed ]4 e, m- { y7 t; ~
f j* h; ?+ T ~. u reset-ticks; b& G9 D" N2 E+ e# v2 o0 m7 f
end& l z. l# ^$ f
/ [' e6 F5 F% [5 B2 C
;; Initialize the global variables to appropriate values0 c+ u. h0 L5 i3 b/ ^
to setup-globals
) i, S7 I& u! h! F3 ^ set current-light nobody ;; just for now, since there are no lights yet
3 C) l8 p# r* w% P# F3 b set phase 0
& D4 I# j$ x: `9 E/ L% J set num-cars-stopped 0- v" [- C2 r9 H6 E; N1 g. y1 U1 ^
set grid-x-inc world-width / grid-size-x
) ]' }1 q4 `# _/ T H1 o set grid-y-inc world-height / grid-size-y
: ~. i+ J2 _5 ]% p- `
' t" M/ I$ r4 [' V! ]* |3 d ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary* C; F+ I2 ?/ J- F' E
set acceleration 0.099& @: y) ] U9 m; p! g
end+ D+ b D2 `* v
: e8 q9 c7 z5 A/ i+ S* M;; Make the patches have appropriate colors, set up the roads and intersections agentsets,9 m# _! \% U: ?7 Y2 X
;; and initialize the traffic lights to one setting+ H/ S. t- o: t w
to setup-patches
0 i. O# d% Y. r8 F ;; initialize the patch-owned variables and color the patches to a base-color
7 a+ g# |$ }, | P$ Q ask patches8 e4 U8 L) Z" M8 o
[' t1 H: m z% T- w p
set intersection? false$ G8 L2 ]$ l1 ^% l1 C. j) d9 P
set auto? false
- j, W* t5 `$ c2 A& r' v$ q set green-light-up? true
0 \ W* J* { N! O/ j% c8 U* @3 T set my-row -1# W+ h+ R; \8 a) p' W
set my-column -1+ S5 ?8 i9 E/ }6 W3 K% C" {& H; B9 y( t P
set my-phase -1
9 t- G" E6 K, V$ X set pcolor brown + 3& b$ Q4 |1 n" R' Z
]" H1 p+ i; U+ F0 I
3 N8 ^; K. O1 y r6 x" I7 V! w
;; initialize the global variables that hold patch agentsets. `2 B* w+ @( m0 H7 ]
set roads patches with2 U4 s7 o7 A' F3 [0 s5 L
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or: D* |: U3 j+ F G4 ] M) l
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]. M% m7 a5 O+ X7 @
set intersections roads with
7 D" A0 H( G* x- p9 p# s [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and- S* n! p- R1 [( _ z8 W
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 H/ i" @& p: m9 l9 ?3 f( b
) q6 [) c- U- f1 V4 W- N" v5 x ask roads [ set pcolor white ]
) ^, G: X" w2 J; W. e' g" R setup-intersections
0 N2 X" X: ?" @# a+ ]! send/ w& F8 z, y) v( }7 S, k: h; M# |* v
其中定义道路的句子,如下所示,是什么意思啊?7 {' x9 F' ]* E" f( K
set roads patches with& I2 ~ W4 S& r# G3 l' ?) D
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or( c" k h9 f4 k: Z- T0 i
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
, G( X& {! e( w V% e) U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? |
|