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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。
- H+ ?9 A t, b& Z8 Inetlogo自带的social science--traffic grid这一例子当中,9 x" {! e3 S- @7 Z: r
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction0 _; p; p- K% ]( Z: }: U
grid-y-inc ;; the amount of patches in between two roads in the y direction
8 ?1 Z, D7 G* d6 V acceleration ;; the constant that controls how much a car speeds up or slows down by if, |' h4 K4 r$ Z) i( i* S6 o: y
;; it is to accelerate or decelerate3 z6 e3 K. ]1 x
phase ;; keeps track of the phase" p# `. h" ]; C# Z# C
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
- t: k/ o+ U" Q% B/ Z7 Z0 `9 u( I7 Q, W current-light ;; the currently selected light
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4 J. k4 d& o1 e8 x4 X8 }: V ;; patch agentsets! U" f5 c5 ^9 |, }! T
intersections ;; agentset containing the patches that are intersections
( x. a9 g$ j( v roads ;; agentset containing the patches that are roads3 d& ]& e7 U) d3 }; ~) t: o8 e
]
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4 v* N' u! ]* P8 X) n3 Eturtles-own
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6 a, L% x/ G9 ?( l speed ;; the speed of the turtle
& B' s. x+ [2 S( U$ N up-car? ;; true if the turtle moves downwards and false if it moves to the right- H' E \2 g1 L0 m* S5 W% e, n
wait-time ;; the amount of time since the last time a turtle has moved$ x& Z/ z( K* B# }. Y6 W% n
]
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads, [- n ]3 p7 w/ {
green-light-up? ;; true if the green light is above the intersection. otherwise, false., M1 V0 Y: s2 c: I1 g
;; false for a non-intersection patches.
$ x# e2 F/ D" r% ~ l my-row ;; the row of the intersection counting from the upper left corner of the
7 o$ O( \- Q- x# @1 y ;; world. -1 for non-intersection patches.
; a& \8 f0 f: s5 g& U( \5 x my-column ;; the column of the intersection counting from the upper left corner of the+ q! J; q. k( u: |
;; world. -1 for non-intersection patches.- o* i+ N) ^- [; {" l+ W+ F: \
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
! F) A; @# ~* M# r6 c auto? ;; whether or not this intersection will switch automatically.. y# E; c8 o5 m/ w5 c) @) H1 v/ V% f
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
2 l, ]& C; ~5 n3 K$ T9 Y5 j$ h;; Setup Procedures ;;1 p% S( u- T+ ^4 C _
;;;;;;;;;;;;;;;;;;;;;;( `5 Y; b! a0 Q: D
0 Y1 j; W1 N9 z4 C) I2 A |) B;; Initialize the display by giving the global and patch variables initial values.4 [# ~/ H$ j* X
;; Create num-cars of turtles if there are enough road patches for one turtle to: p6 I7 t1 d8 G3 i
;; be created per road patch. Set up the plots." B% B9 @1 m* |
to setup! ~5 B2 T0 T, i5 P9 p& k$ W
ca
4 z% K' i4 l7 A& O setup-globals# h* B2 {- R: O& A) D! E
% C# ?0 A) \* {2 {4 J: T ;; First we ask the patches to draw themselves and set up a few variables
; p' N2 R4 q1 H9 M/ i- } setup-patches
% s$ Q* z3 }1 \! r8 c make-current one-of intersections- y; W( `, r2 u+ F" ?
label-current
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+ J0 R( L# j! f. q" d" ~, R set-default-shape turtles "car"/ p+ N. k0 t& R- K& u# H
" r1 Y2 w2 X* V* b if (num-cars > count roads)- w$ B) d/ p' v
[
4 I' } o# W; a! o( N user-message (word "There are too many cars for the amount of "
/ d& }0 D' E. C; D. T2 r7 \ "road. Either increase the amount of roads "
& h3 v- Z% w6 A) m: m "by increasing the GRID-SIZE-X or "( k% b4 ^+ z6 k3 f7 B1 [2 g+ I
"GRID-SIZE-Y sliders, or decrease the "
?1 y _; h: x8 U" l( V3 Y "number of cars by lowering the NUMBER slider.\n"
. j7 Z! ^3 O1 ^7 [ "The setup has stopped.")! M5 q0 Y7 s0 J& W5 j4 S! y& A
stop
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1 P/ G" R% _# V- x0 g ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color0 |6 @! p# ~: P% A4 X! ]
crt num-cars; V) H3 W% O, } W
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setup-cars
; [; C+ \1 V! @' e& D" w. E set-car-color
7 M1 i% f6 q" ^& h+ m6 K: s. D record-data4 P2 k2 C7 v- U# B
]
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;; give the turtles an initial speed
( j4 S0 [3 Y, l9 a5 H/ f ask turtles [ set-car-speed ]
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/ A( P( ~ ?. A5 Z/ ~4 P4 e reset-ticks
4 F1 X, e3 [$ D# e [end7 C, i( _9 g8 E" x6 {4 K: G
4 {0 E0 v+ c) g: q4 B' F;; Initialize the global variables to appropriate values
" [, x: x, \; U. Lto setup-globals4 u/ b8 N# l6 r. \
set current-light nobody ;; just for now, since there are no lights yet; T6 I9 t! H- x3 D
set phase 0" p! P( o; \! f8 Q
set num-cars-stopped 0
, e" ^4 ?$ p+ @6 X* {. w& N set grid-x-inc world-width / grid-size-x9 R2 `4 J! i0 _$ ^4 I
set grid-y-inc world-height / grid-size-y
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* n' D1 N: S( D ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
C5 j( |% T# m. b* d set acceleration 0.099
6 K( p9 N8 i1 H) J% S; uend$ M& ~: y) E$ |
9 E7 Z* c2 K- H4 d& Y) H8 g! p;; Make the patches have appropriate colors, set up the roads and intersections agentsets,' s+ `4 ^ G0 ^
;; and initialize the traffic lights to one setting" I. c3 D3 ]1 y q) A, x
to setup-patches
9 M# {7 E' j/ v [% v ;; initialize the patch-owned variables and color the patches to a base-color8 Y. e- U. X! {2 R
ask patches) f" j, @% r1 g: ^! y! r
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set intersection? false, d1 o7 T7 L1 z8 }% z! f
set auto? false- Q( x9 @1 a9 X
set green-light-up? true0 z2 K! S4 @$ l; p
set my-row -1
/ Y! K5 V: I6 b, C+ \- Z! | set my-column -14 z& D4 ~4 e, i% j% B! M0 H1 ?- B& H
set my-phase -1
; p/ f( J. p9 s1 n5 U7 d! @ set pcolor brown + 3, ~; j' c4 r0 \
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8 {& a/ z5 b4 |2 Y4 b( C ;; initialize the global variables that hold patch agentsets" k9 l7 |) u9 _) X2 |
set roads patches with
1 C) C2 Y: H. |* s6 F: d1 U# v [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or$ ^& a$ U: `3 E9 d2 b; [
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: G; W$ \+ A3 ^2 m9 X. ~. O2 ] set intersections roads with1 G. u) P$ h/ l9 X4 l% \; \, y
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
+ W8 h+ p* @3 s" X, r% ~5 g$ l (floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ a7 I. r- |$ @( l
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ask roads [ set pcolor white ]
+ ^6 m1 i4 X* p7 D2 T6 `! P( e( ` setup-intersections9 i4 ^4 a1 ?7 F+ H8 u. Y
end5 D, I$ v8 {1 M ?- B' F
其中定义道路的句子,如下所示,是什么意思啊?
, m# W6 [) a y9 j set roads patches with
5 B3 k9 h+ G5 B B$ M [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
, |. w& o/ M& R: U2 Y( J (floor((pycor + max-pycor) mod grid-y-inc) = 0)]; F, }! h) ]+ z* H
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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