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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。9 ?% j# l: ]: E0 u- p
netlogo自带的social science--traffic grid这一例子当中,
) o0 z0 I' y( f3 j ?6 a/ z% Bglobals
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/ {* n3 t/ C) ^9 r grid-x-inc ;; the amount of patches in between two roads in the x direction' w$ c6 v# r' W7 ]" I6 b
grid-y-inc ;; the amount of patches in between two roads in the y direction
! o# |# w, m8 E9 a acceleration ;; the constant that controls how much a car speeds up or slows down by if
. D: x+ v) t2 ~/ \! i" T2 x# C ;; it is to accelerate or decelerate
( f/ J7 F5 ]" n2 O! e8 j phase ;; keeps track of the phase
: b) @: D& m" Q num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure0 _, E w" m# d8 B* J. ~8 F, G
current-light ;; the currently selected light
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;; patch agentsets' _+ G" @# g7 _# ], Y* {5 f
intersections ;; agentset containing the patches that are intersections
; h: m! ^# H; B" _7 |2 _7 b! } roads ;; agentset containing the patches that are roads _) o5 R& d& z& c# }* ?
]
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turtles-own/ | m3 X8 Q0 r+ J, S* m
[
4 A; U M' O" {, J3 D5 g% k% M speed ;; the speed of the turtle
7 r( n( j1 R* A. s up-car? ;; true if the turtle moves downwards and false if it moves to the right
4 L. g& C- |) [ wait-time ;; the amount of time since the last time a turtle has moved6 O, b; d! J L0 u8 D
]
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patches-own; O# I I- s& i3 e: `
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intersection? ;; true if the patch is at the intersection of two roads
d6 t& O1 X- V+ a5 [ Z/ } green-light-up? ;; true if the green light is above the intersection. otherwise, false.
6 ]" O7 I( W3 F ;; false for a non-intersection patches./ S5 v' f2 p B' E; t
my-row ;; the row of the intersection counting from the upper left corner of the
/ W; ?. M$ P, O# z) T ;; world. -1 for non-intersection patches.
8 ~; V+ ~+ p6 B5 w5 p* V my-column ;; the column of the intersection counting from the upper left corner of the! }7 X+ c1 T5 g h8 G
;; world. -1 for non-intersection patches.
' x3 C- d9 M9 P! F5 m my-phase ;; the phase for the intersection. -1 for non-intersection patches.
* v, k. M" a7 i2 @ auto? ;; whether or not this intersection will switch automatically.
+ a( j1 g' i; @/ v$ g ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;% s/ N p4 K- P _) Y
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.8 e( F5 K- t! Y M, B
;; Create num-cars of turtles if there are enough road patches for one turtle to
9 g4 T$ Y8 L; O8 d;; be created per road patch. Set up the plots.4 Q* o( V3 b2 d' m% {
to setup
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; n- Y4 Q4 t7 i setup-globals R! G: d* g6 U0 q+ v
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;; First we ask the patches to draw themselves and set up a few variables# @8 u7 a; n* X$ g+ f- q
setup-patches
6 H2 D% L7 q- P* M+ n0 ~ make-current one-of intersections
5 ]& b6 ?0 r) @0 q; Z" I label-current
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5 v; J# o4 `! R0 C, i4 y set-default-shape turtles "car"
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if (num-cars > count roads)6 F; X0 D, v7 S- J/ v6 Z- W
[
3 v: [ r% H! @0 X% A user-message (word "There are too many cars for the amount of "/ ~; p5 O, Y# K% H2 E' B' w
"road. Either increase the amount of roads "
( L4 L9 Y+ U- }% L) X, q7 D2 p "by increasing the GRID-SIZE-X or "
% p1 ?' e% K: I1 ]& D! b: g4 q "GRID-SIZE-Y sliders, or decrease the "4 n' c: G0 i' z5 J, u4 ?
"number of cars by lowering the NUMBER slider.\n"; e+ ]% |9 Y4 ]9 C3 {; s' _9 L m
"The setup has stopped.")
- P# o4 T: h8 S+ W1 _ stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
, R* n5 x5 s; j# F6 a. X crt num-cars
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9 B7 _' K$ Q" q6 w* Q. \ setup-cars! l4 l: \* r$ f C! F; O9 A) F, M
set-car-color2 H7 p0 q3 o, b7 t E! Z
record-data8 u. w/ i( P8 W
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;; give the turtles an initial speed3 N" T4 T4 M5 }. |0 }
ask turtles [ set-car-speed ]
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reset-ticks! q1 D/ G9 A3 z
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;; Initialize the global variables to appropriate values% @) Y- ? ^2 m2 ~7 E$ ?/ {
to setup-globals1 t Q9 ?2 ~5 G
set current-light nobody ;; just for now, since there are no lights yet
0 ]. p) p/ p& l; H& p set phase 0
7 c/ O( O% b- L& i2 R3 Z set num-cars-stopped 0
& F1 ]# J( V0 P- } set grid-x-inc world-width / grid-size-x
' b# t2 X3 H$ ] set grid-y-inc world-height / grid-size-y) G$ V% r& V- P6 h4 a/ n6 X) |# L
0 N! K+ P* c% O; e1 v5 _ ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary* g) m, K* n# n; B+ L3 y
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,& D. R! M2 a7 M
;; and initialize the traffic lights to one setting* ^+ Y- e2 M* Z$ K4 } i% E
to setup-patches
: q8 r/ r" h9 B4 u( ] ;; initialize the patch-owned variables and color the patches to a base-color
2 g4 p6 F8 d4 U/ ]* b* V ask patches$ Y4 I |" B" Z) T% ^
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set intersection? false
1 V) c0 m9 g3 r+ ^ } set auto? false8 W1 Q6 C# d/ Z$ p/ Z
set green-light-up? true+ y, d+ J' u" N3 o( z3 t0 f
set my-row -10 A2 t4 H' f# R4 @
set my-column -16 B: B' N9 i K2 i: t% j: S
set my-phase -1
& V5 s2 X% N# E set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
" O4 J+ Q$ U' F, h' N. y" [% F set roads patches with
\" c- r7 S) s$ W( U, J [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or! J( E% u9 T: d9 v7 n) }
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. M) a5 o! G0 V, b4 \ set intersections roads with
7 t% }& E7 C0 ~* P [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
3 {8 e$ I0 `$ j/ b* A (floor((pycor + max-pycor) mod grid-y-inc) = 0)]: Z7 i) I7 Z! g8 p" T. [8 m+ z* s
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ask roads [ set pcolor white ]
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end
! u" t! T4 z8 p% n, o+ L: W6 L3 i其中定义道路的句子,如下所示,是什么意思啊?
3 L6 d K3 p7 R! b K9 z set roads patches with
2 T* ?& N$ H! Q$ ^ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
% J( f3 t% r# }. C (floor((pycor + max-pycor) mod grid-y-inc) = 0)]; g' [6 Z6 E- [+ r$ K3 K
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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