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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。/ _" W0 _) H# L( m- ~
netlogo自带的social science--traffic grid这一例子当中,
, A( I! y! w6 G* v. ^globals, D' R/ |0 C1 T6 r2 z$ G
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; V* ~! m; s V( `# g' G4 ~ C; [ grid-x-inc ;; the amount of patches in between two roads in the x direction
9 _$ A6 ]/ G2 A4 ]" F grid-y-inc ;; the amount of patches in between two roads in the y direction
* D, ~# M0 _. j$ W% E- b, P/ S acceleration ;; the constant that controls how much a car speeds up or slows down by if
0 _/ c. u1 R' m2 k3 A+ K ;; it is to accelerate or decelerate
B' ?3 m1 w( m: R* G9 k( [) B, U phase ;; keeps track of the phase1 B# t9 u; w; W
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure3 N; M4 U8 o# o% | M; ? g* k
current-light ;; the currently selected light
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; |. t( C4 z7 J7 s: i3 D ;; patch agentsets
- G% o2 j, V! _; J. X intersections ;; agentset containing the patches that are intersections
, H9 J$ t7 s# i0 @" v roads ;; agentset containing the patches that are roads8 x3 }' B& k# A7 M0 R
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turtles-own2 V. h; [+ b# w( f
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speed ;; the speed of the turtle B& J6 J6 h. D' O
up-car? ;; true if the turtle moves downwards and false if it moves to the right
) [" g! c$ X! L7 p wait-time ;; the amount of time since the last time a turtle has moved
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patches-own6 [( w2 I2 P: N& s( S9 F2 L
[
N- t7 f$ U3 o$ }% i intersection? ;; true if the patch is at the intersection of two roads4 Z# r9 W+ R8 q+ Q! u
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
, J: o8 i5 O* o8 `/ F- c% r ;; false for a non-intersection patches.% C7 k+ g2 e7 U* r! I* T% p
my-row ;; the row of the intersection counting from the upper left corner of the
3 k, E0 s+ K7 O ;; world. -1 for non-intersection patches.; e, Z- e6 Z$ k0 m2 ~4 a
my-column ;; the column of the intersection counting from the upper left corner of the
; e( z& \* N# e6 c" j ;; world. -1 for non-intersection patches.
7 I( C3 C8 q: o& R- i0 d x8 O my-phase ;; the phase for the intersection. -1 for non-intersection patches.1 K. }) \ w' _, y8 s# d
auto? ;; whether or not this intersection will switch automatically.
+ Z% t' B0 r/ y. R) R3 K0 @: `0 W ;; false for non-intersection patches., f. d0 `2 `9 w4 Q x
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;;;;;;;;;;;;;;;;;;;;;;
8 k' b6 x0 j9 \' w/ x/ Y: P;; Setup Procedures ;;
8 Q* R) s3 C9 _0 l+ R;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values. L& p) o/ a- i
;; Create num-cars of turtles if there are enough road patches for one turtle to
* R9 I* d Z1 x) ?1 l;; be created per road patch. Set up the plots.) b" J, y% H: }2 e. H5 @, c5 F
to setup+ X. C2 f7 R) k; U
ca
- F8 z7 p' g" P7 \; | setup-globals8 E7 H A+ w* `8 t7 n
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;; First we ask the patches to draw themselves and set up a few variables# Z% h* E) I1 n/ o7 U: B6 C
setup-patches
+ d# m6 `9 O, ~/ u8 b/ ~ make-current one-of intersections
( j$ l3 _8 ?" ^- q1 h8 R label-current
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& K& G" _' |1 L8 z0 v( J set-default-shape turtles "car"8 i4 o: K% V) n9 H6 y; V& k
% o. F$ u" K5 J- v! a0 T2 V/ F8 b if (num-cars > count roads)( c h6 k% A: t, Z9 H
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user-message (word "There are too many cars for the amount of "! J3 i0 f5 i3 k% O: }
"road. Either increase the amount of roads "; R* S: _: H3 }3 a5 {: N% p
"by increasing the GRID-SIZE-X or ": L+ G8 _( @* O, ^3 K; D
"GRID-SIZE-Y sliders, or decrease the "
9 h# Q* o1 ^/ i# M "number of cars by lowering the NUMBER slider.\n"7 H; |! f9 Q) Z4 y) ]& N! L
"The setup has stopped.")# s! @- O: q p3 P) |
stop6 {+ _- ~3 N/ Z& j
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$ Q) D! B- A0 m# z9 f A0 I) P9 ^ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color1 a7 |2 F8 t# ]" D# g3 y+ u
crt num-cars
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setup-cars( ~1 g9 N, h# w) k% U" G) E% n% Y/ s
set-car-color& N9 p5 X: I$ w5 u/ w m
record-data
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;; give the turtles an initial speed
1 m; U' w8 J3 P j! N ask turtles [ set-car-speed ]! d) J [/ e8 q$ C
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reset-ticks
& Z* ?1 {) q( f0 O& A6 y8 l$ Q: ^end
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/ p3 E' |6 M2 V% T* };; Initialize the global variables to appropriate values# ?, y( m2 d% }+ n
to setup-globals
+ i. |' @; i) W5 M set current-light nobody ;; just for now, since there are no lights yet
0 P# B$ R/ v5 t2 o/ A set phase 04 x$ F$ n& G" E+ f/ U
set num-cars-stopped 0% x- ?0 c7 O9 W: T. b% |: [
set grid-x-inc world-width / grid-size-x
- h* d5 ]! w' m3 T V set grid-y-inc world-height / grid-size-y
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, k$ o: v! [' D+ b9 D8 d% ~) D% o ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
$ k: z) ~5 B- Q$ z7 r: u set acceleration 0.099( U& P+ ]. I, _" e; t% @3 T- B$ ~
end$ o8 f& a/ ?9 R
* i6 T9 f' h& H. _' Z6 r: S! e) V;; Make the patches have appropriate colors, set up the roads and intersections agentsets,& e/ t; K S u+ _- g
;; and initialize the traffic lights to one setting
: G5 f; N3 e& G7 _1 Z1 D8 wto setup-patches
* D) p3 d* R6 T5 B3 U" a ;; initialize the patch-owned variables and color the patches to a base-color
0 x7 R' P4 r$ f+ E; b- l. o ask patches( i2 V! h' Z/ i
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6 n- Q% Y+ e1 Y) ]2 T( X+ q set intersection? false
" x+ O) c, x6 |( p }# c set auto? false/ A( W0 m1 z% E4 L' |" x9 i, K
set green-light-up? true
* ?$ _, f" c. _/ l c: E6 c7 M2 e set my-row -1+ ?$ v& P$ U- o' u: ~1 S
set my-column -1( Y1 L2 A% b0 {( B6 O* C
set my-phase -1
: c x' @! J e; _ set pcolor brown + 35 e5 L6 ^5 e( R" K4 B' ~
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;; initialize the global variables that hold patch agentsets
( A) [3 h( s! t" l; F2 I set roads patches with( i' \; y4 d" D5 P. |
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or5 A5 E! D8 E1 Y; a" H* a' A
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]" p" y3 |2 q' E' O
set intersections roads with
0 o i6 m' C$ W [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
* Z1 _) ^" H, P0 L# @ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]" z' R# S" W, f: j4 C9 `4 j
. K2 @# l: o5 t' s2 [5 V ask roads [ set pcolor white ]- ~! v' V2 D! j* C+ B9 T& E( {& l
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?
' l# V9 a' z: H7 e, c' U. W5 x( M2 v set roads patches with; ?& a! {) B! c: S2 V) f
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or. m& x; K1 D' R, u8 v
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 a' Y ^- i! `! X* W/ J% R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? |
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