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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。
* v3 G- P, a" T* _3 Inetlogo自带的social science--traffic grid这一例子当中,3 C; w t1 G& h0 t: C z
globals Y8 q# W8 a0 ^
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grid-x-inc ;; the amount of patches in between two roads in the x direction
# [ S) V$ H E" l4 R4 r grid-y-inc ;; the amount of patches in between two roads in the y direction$ X/ Q& m! u6 W6 B1 ?
acceleration ;; the constant that controls how much a car speeds up or slows down by if7 |) G% W; I* g# }4 f+ K, Y
;; it is to accelerate or decelerate
5 i$ U% t3 f/ |% | phase ;; keeps track of the phase
, S9 U1 y; l2 t+ U5 P. p num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
! U, Y$ v* v9 N current-light ;; the currently selected light3 v& w Z0 W# M* v" r. V/ _8 Q6 D
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;; patch agentsets1 ^& C0 ?4 ~3 Z! M& J9 F
intersections ;; agentset containing the patches that are intersections
: S9 K! O) v4 E roads ;; agentset containing the patches that are roads
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7 e3 ^ O4 R P/ }
8 w) m' v* } xturtles-own
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speed ;; the speed of the turtle9 f$ u; c* k+ Y
up-car? ;; true if the turtle moves downwards and false if it moves to the right
3 c2 i4 k' z W) c1 h1 P# F' ~ wait-time ;; the amount of time since the last time a turtle has moved
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patches-own6 ?: |8 G$ c8 }9 v( ^8 C+ }
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- u k: I. ^8 \. @ intersection? ;; true if the patch is at the intersection of two roads
6 }* ^! _9 V$ y# f9 a green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! ~. Z3 I/ V% A+ i/ ~ ;; false for a non-intersection patches.6 V2 W% o1 @0 R1 ]& _. g# L" A( T
my-row ;; the row of the intersection counting from the upper left corner of the
* |% ]. e) O4 R4 C* Y! y ;; world. -1 for non-intersection patches.
! a$ R! ^4 @3 g my-column ;; the column of the intersection counting from the upper left corner of the
4 v. R# K4 ]4 U7 s ;; world. -1 for non-intersection patches.
1 P2 {: M2 ]9 q. J* D C my-phase ;; the phase for the intersection. -1 for non-intersection patches. g! _- U9 ] ^3 l( _/ D
auto? ;; whether or not this intersection will switch automatically.
" Q9 ^- C, y: j9 H. n: M! Q5 ~ {) O ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
+ Z5 r( G$ L [$ a" a6 q, J;; Setup Procedures ;;0 V R- ]/ t) T
;;;;;;;;;;;;;;;;;;;;;;
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% x5 t7 \9 Y! Z ^3 u;; Initialize the display by giving the global and patch variables initial values.
% Y# Z( Q9 V: V# d/ V;; Create num-cars of turtles if there are enough road patches for one turtle to
! t: \6 l- |, G# r: N;; be created per road patch. Set up the plots.- y9 P J1 q: n. T+ q
to setup
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1 E, Y* u, `+ W( D$ ]& c% C setup-globals0 Z$ y0 [# s3 Y) t f4 R2 d2 O
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;; First we ask the patches to draw themselves and set up a few variables+ N: L5 x0 F% h9 U% y/ R/ D1 H
setup-patches, G- d) v( y$ v2 ?8 l5 P/ K* E, v
make-current one-of intersections7 r [, L7 y2 ?' w
label-current6 g8 }, P4 ^9 p! ~5 Y- `' a
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set-default-shape turtles "car"1 z) Z5 L$ F9 H
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if (num-cars > count roads)
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) \5 _3 N6 `7 O2 q, t8 X2 Q user-message (word "There are too many cars for the amount of "+ O) c/ z: T$ @0 X: m( ^3 D* @
"road. Either increase the amount of roads "& e) A8 j3 G2 I. `* o
"by increasing the GRID-SIZE-X or "2 G* V( T$ v, x h! z8 Q
"GRID-SIZE-Y sliders, or decrease the "% v+ ^8 f1 G8 }* n" K$ M
"number of cars by lowering the NUMBER slider.\n"8 Q1 L, B7 F6 ~4 V6 g/ s2 Z
"The setup has stopped.")
7 K0 Y' T! I' k* e% F: W' y# M stop
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7 Q: N! X0 Z4 @- V) U' _ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
$ `9 g8 R0 n( ]8 j crt num-cars
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* f% |7 L: Y$ Q- A9 e6 z( S setup-cars
& m7 J6 K& i2 g5 R2 i$ p( m: a' K set-car-color
" U3 v5 Z% q3 @8 y% s1 k record-data+ j( i- ]$ t8 x) z. R' t' V6 L
]
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;; give the turtles an initial speed
. ?1 U% E; n( G ask turtles [ set-car-speed ]* T* H$ }2 c+ v/ J% ?) s/ v
* h& ~$ J Z/ P reset-ticks( [0 Y3 F1 z* V) S0 i4 W
end9 K3 U; Z( ~7 C% c
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;; Initialize the global variables to appropriate values
& V7 m! y4 G1 f+ T0 B' ~to setup-globals
9 X. E( I+ q Q, g" X: Q set current-light nobody ;; just for now, since there are no lights yet) b# i) N# C5 V* F+ X
set phase 0, }6 i* D/ b. x& ^- y; u s
set num-cars-stopped 0
# C) I9 \5 ]5 ?$ | set grid-x-inc world-width / grid-size-x
6 y* G% n; {, o) k7 E- q( y set grid-y-inc world-height / grid-size-y
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# M) y9 v8 }; T7 z ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary* q6 o/ p8 Q# e' E+ v. L$ F) l
set acceleration 0.099# a( Y! `4 S9 H$ ^$ z' Q4 e: X
end
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# K( x) K8 Y3 q0 b- E Z;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
% ?8 z5 P6 q7 v4 W/ l;; and initialize the traffic lights to one setting0 P' D5 P( E. X
to setup-patches
" X5 K6 f! z3 u( a) ]7 N. Q ;; initialize the patch-owned variables and color the patches to a base-color
) a' B# p3 p |. ~( B, d0 K+ ` ask patches2 r+ u( ]5 m; }6 d+ Y# V
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5 a, O* t$ p* a2 ~! u set intersection? false* q' ]8 _" ~" |! \0 B0 J( @9 i
set auto? false
6 c/ E& a/ L0 D/ A. h4 i set green-light-up? true
( k6 e0 n0 e8 M8 V set my-row -1, K6 d/ p& t4 Q# P8 G" ^2 X8 d, k
set my-column -1$ @# g8 e' f2 R+ S" V% a4 k6 J
set my-phase -1$ y+ e2 ^5 J$ H: T0 D
set pcolor brown + 3
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5 R+ ?7 K! W$ [% R* \8 s2 g ;; initialize the global variables that hold patch agentsets
0 F7 ~0 y6 a6 ^9 u" U6 h2 W set roads patches with
( |% B) m$ O; L/ Y* ^& T" X1 X; N [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' @2 t, j$ F( L- c
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]% P' P0 m/ q5 ]2 i2 p' U
set intersections roads with
7 o- I: v$ K$ O: F$ J: J [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
$ t- ^1 F" u; l! B; P0 k1 }/ z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 a7 F; r1 B0 r
! R2 h" A) ?/ o7 ^' Y ask roads [ set pcolor white ]
' i l4 `4 S" W% ~; E' V setup-intersections0 n+ c1 k& k6 y% }7 ~2 \
end( i% r$ s# O" y: G4 _# Z: A
其中定义道路的句子,如下所示,是什么意思啊?
& ]- C* L. ^6 K+ Q: M! K0 x set roads patches with
) t p0 e3 W4 `" j8 t3 Y5 A8 i [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
% |( I# c& ?( K- C2 j (floor((pycor + max-pycor) mod grid-y-inc) = 0)]" Y- k9 l' T3 D$ |
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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