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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。
8 w0 K/ c, |- S4 v& B( }7 M3 ?netlogo自带的social science--traffic grid这一例子当中,
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grid-x-inc ;; the amount of patches in between two roads in the x direction2 p2 Q) J( }; I6 P8 t; W7 X
grid-y-inc ;; the amount of patches in between two roads in the y direction$ s( z, S3 ]2 i3 y, ~
acceleration ;; the constant that controls how much a car speeds up or slows down by if7 ?( q' F2 x! z* L& a
;; it is to accelerate or decelerate; f) o8 ?( D7 t9 S. m1 U, ^
phase ;; keeps track of the phase- b' }9 c& Z; ]1 {+ H
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure M- N8 W, N! ^# x! U
current-light ;; the currently selected light
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;; patch agentsets
6 h/ J+ u, B2 _8 j% E9 H3 ? intersections ;; agentset containing the patches that are intersections2 k* a! r7 L) V( |/ o; v l4 A
roads ;; agentset containing the patches that are roads" J# X1 `3 r4 [6 K& I8 B4 f: L; P
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' {# d- U% L# Z2 V+ k0 Xturtles-own
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; k: B: _/ o$ M" G' n speed ;; the speed of the turtle4 N% ~8 \. H8 T9 V" S7 ^# o# J
up-car? ;; true if the turtle moves downwards and false if it moves to the right
( [8 ~/ {/ H0 T* n% d wait-time ;; the amount of time since the last time a turtle has moved% X$ i4 l+ s& P2 K
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads' x. o2 A6 ]5 g& A
green-light-up? ;; true if the green light is above the intersection. otherwise, false. e: ^3 u" h" x: E) A
;; false for a non-intersection patches.- M- H' y3 D! {0 V' @
my-row ;; the row of the intersection counting from the upper left corner of the
& z3 N3 N! O+ E9 | ;; world. -1 for non-intersection patches.; Z8 C) Y2 P$ E7 t3 [
my-column ;; the column of the intersection counting from the upper left corner of the
! r: ~ G, L& C; O5 t4 [3 B ;; world. -1 for non-intersection patches.
5 L" M2 X: p0 s) I my-phase ;; the phase for the intersection. -1 for non-intersection patches.
# d o; O$ D7 a& g2 j6 ?& |# q" x auto? ;; whether or not this intersection will switch automatically.* u! M6 ]& P+ B' G
;; false for non-intersection patches.# |7 E: J9 d. A5 g7 I+ c
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$ K: U- y; H+ Y0 R K- Q, I;;;;;;;;;;;;;;;;;;;;;;' I, N; J# G- j9 d: c0 I8 v
;; Setup Procedures ;;
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3 j" K- A6 ^* o;; Initialize the display by giving the global and patch variables initial values.
/ ` k% H% H4 l3 ^, `;; Create num-cars of turtles if there are enough road patches for one turtle to
# j1 c. Y* v- K# P;; be created per road patch. Set up the plots.: E' m2 c+ u0 V8 o1 f
to setup0 S0 t2 {! A5 @" l
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setup-globals; v7 H2 H- g8 D
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;; First we ask the patches to draw themselves and set up a few variables" r2 n! K3 b8 y& e1 \" |# C& q
setup-patches. [% A. F5 ]/ `. A- p9 P- v
make-current one-of intersections( i! n6 Q \8 A; X8 p7 G- o
label-current
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9 s5 N8 q$ ?3 L6 N set-default-shape turtles "car"
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: g+ q0 m- H t2 \# q if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "- A5 U% Z; K, c/ P
"road. Either increase the amount of roads "
( W0 Y6 M) b9 e; y! ^( H "by increasing the GRID-SIZE-X or "
. [2 q O6 a; ^' W5 O "GRID-SIZE-Y sliders, or decrease the "
4 u) A& a, d( x! Q "number of cars by lowering the NUMBER slider.\n"
& n5 ~4 l; u1 W8 e' M "The setup has stopped.")3 m" C! Y- `* _: G7 k0 [+ W$ @
stop& T0 @, O. |# _$ f3 U: x3 w$ g
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
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setup-cars3 i- |3 K$ }" K+ t2 L- G
set-car-color
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;; give the turtles an initial speed" B, l% _% a/ X8 G2 T5 r2 o$ \ U
ask turtles [ set-car-speed ]
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0 C( t* S$ L2 t% {; mend
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;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
" L8 ^2 _+ G( E/ F6 R& s set phase 0
8 Q& }* N. N: }' k4 x! p0 Q& y set num-cars-stopped 0- |6 L8 n& c) o$ {( b
set grid-x-inc world-width / grid-size-x% H8 {& e4 |' k9 O: A
set grid-y-inc world-height / grid-size-y
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+ m# U( X& r. c; Q7 z5 y! `6 Z+ F8 F ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary- R0 w6 z0 S, b1 ~) R) \* u
set acceleration 0.099
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* J, S- Q9 e- @) e8 p5 G: U8 N;; Make the patches have appropriate colors, set up the roads and intersections agentsets,! q2 f4 I: C" ^+ @2 X- ^
;; and initialize the traffic lights to one setting; y& j. H% G& N$ b6 y9 m! z
to setup-patches" N: ]3 F. C* e7 m! @
;; initialize the patch-owned variables and color the patches to a base-color. P1 W t- K! S2 J G' o* T5 F
ask patches9 d" N2 i& O! m. n
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set intersection? false$ o$ W6 H2 X! ]1 f& P$ y& u
set auto? false2 O; H5 A3 C. a4 h% Z" H
set green-light-up? true; g2 j7 \. _) B" |% i+ [
set my-row -17 N; p* X$ ~% [$ e, T l7 C
set my-column -1/ L1 F8 u4 k( i/ E/ X. n* |
set my-phase -12 S. M2 @0 H [8 `& Q- c1 a/ F
set pcolor brown + 3
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9 b0 I7 c, Q; H: o& O0 e& s: G& p! e ;; initialize the global variables that hold patch agentsets
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! C# i2 b* t! e0 u [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
- l M1 m; r1 P- S6 n/ D9 O* W/ E* k (floor((pycor + max-pycor) mod grid-y-inc) = 0)] `/ K7 ?" j& I: A* n
set intersections roads with& y, L7 M9 T5 j( T
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and7 b7 `# B! {2 q7 a W. m2 k2 Y# z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]. K. a) g) P! m8 w
3 S9 x" [% R+ N ask roads [ set pcolor white ]. l5 I* p- }8 b! n+ i' t
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?
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[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or* l" d; V+ i/ f4 P
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 A1 `7 i [+ _) B1 @. 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? |
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