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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。$ D% A3 w4 ?. z3 t3 Z2 f9 q/ \
netlogo自带的social science--traffic grid这一例子当中,
! z+ `% u5 m3 u& l8 ]: Eglobals
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: a" ^2 I& b( Y4 x! b1 m: F grid-x-inc ;; the amount of patches in between two roads in the x direction
. m1 U/ n8 O" O. |2 J& W5 S grid-y-inc ;; the amount of patches in between two roads in the y direction: [6 C* a0 m5 m6 B
acceleration ;; the constant that controls how much a car speeds up or slows down by if2 \; M3 D0 \3 o
;; it is to accelerate or decelerate8 s. d I, g, f% e& x
phase ;; keeps track of the phase$ i5 G: m6 l# r: B0 M
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
6 X6 z. t; ~1 r8 m8 f/ N- W current-light ;; the currently selected light$ f$ r" ?7 P; s
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;; patch agentsets
/ V' q! h, A# Q9 C intersections ;; agentset containing the patches that are intersections/ Z# I7 E U0 m7 m: s6 L
roads ;; agentset containing the patches that are roads
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+ p, F2 K! w7 u! q/ ]# D1 _turtles-own( C2 m5 S& E" {$ d1 x
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speed ;; the speed of the turtle# H; F/ `5 l' [- \
up-car? ;; true if the turtle moves downwards and false if it moves to the right, z/ m9 E: m/ v' ]7 @, E) p
wait-time ;; the amount of time since the last time a turtle has moved
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. a) O6 C6 r5 O! Hpatches-own- X" M8 j" C4 {4 m( _
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intersection? ;; true if the patch is at the intersection of two roads
% Y3 I' o# [! g# D green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! g1 k/ T j4 }& \2 V+ B: }. s. g ;; false for a non-intersection patches.* Z: e b9 l" s2 C( h; x
my-row ;; the row of the intersection counting from the upper left corner of the) P8 w6 h" L% a. i" e# P
;; world. -1 for non-intersection patches.4 F! _/ ?# w9 b# u" F4 H
my-column ;; the column of the intersection counting from the upper left corner of the) y4 p5 ?' i7 [0 }
;; world. -1 for non-intersection patches.- _* P; T Y2 H9 v4 ^: Z
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
$ o! A: D2 p2 ~ X7 c, e6 O8 t auto? ;; whether or not this intersection will switch automatically.# N$ l2 ]( X% h
;; false for non-intersection patches.$ o5 U+ p5 L# M; N- U' @- x
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. ~! {/ r, Z' o _% @/ J. y0 F;;;;;;;;;;;;;;;;;;;;;;
3 Z# G/ b9 M' b;; Setup Procedures ;;4 o8 h) H3 [* i- {1 N2 ~; X) Q
;;;;;;;;;;;;;;;;;;;;;;
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( b! L3 U4 Y$ J- r;; Initialize the display by giving the global and patch variables initial values.
" T) T" e( |0 } K) |1 V' A7 b;; Create num-cars of turtles if there are enough road patches for one turtle to4 S& i4 W6 }) X. e5 G" a. S5 }
;; be created per road patch. Set up the plots.
/ Q; I S" i! n. G4 `8 |7 ], `+ B8 zto setup
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/ C' R4 O' }3 |- c) o0 T; { setup-globals
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7 u# _/ C9 W% L4 a( z& Y1 J ;; First we ask the patches to draw themselves and set up a few variables( c H# N; @. ^, i( t5 `2 v, {& r6 ]
setup-patches
5 m4 m) v) ?5 L. x- L make-current one-of intersections" t4 U+ C9 {; P1 _: V4 D
label-current: ^: f G( C+ o* O/ f8 x0 Q1 t
# p8 E5 Q1 B+ c+ `3 _6 s set-default-shape turtles "car"
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if (num-cars > count roads)# l. s& z G, C5 e
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user-message (word "There are too many cars for the amount of "" E5 D7 a1 l+ U
"road. Either increase the amount of roads "0 S6 F+ `8 z5 R$ \
"by increasing the GRID-SIZE-X or "
4 X. O4 ?9 K5 a- W$ i4 x- l$ Q8 s4 O "GRID-SIZE-Y sliders, or decrease the ", |) x7 a) x0 T. R7 P
"number of cars by lowering the NUMBER slider.\n"3 W" n; o, W8 Q$ m4 |
"The setup has stopped.")# [7 Q# H: I2 y0 ]6 l# H# {+ Y7 l
stop
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) P$ E$ M( H$ u/ P, \% E2 l ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color6 W, O" L& Z$ U$ S: ]2 c
crt num-cars$ b, @' M M* v- M9 i5 T [ K' M( i
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setup-cars
2 E- z3 d* C; d/ p6 ]+ X/ Y2 @ set-car-color- R9 }7 e/ g' V0 T) c! n W
record-data
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! B& ?$ v) i+ m4 j/ K ;; give the turtles an initial speed
/ Y+ K" |+ W* F8 F/ G& t, m+ j ask turtles [ set-car-speed ]1 ]* u2 j+ J6 m1 e* J( _4 D
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reset-ticks
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;; Initialize the global variables to appropriate values9 H' O) q/ @ c! T1 n
to setup-globals9 t- F1 T z6 p6 w& @. q6 k
set current-light nobody ;; just for now, since there are no lights yet) M0 X8 `% e6 }: K
set phase 0( X Q @: ^* c3 Q2 n
set num-cars-stopped 0
: l6 X* u% K( B/ b( I set grid-x-inc world-width / grid-size-x9 Q% p+ Q# [& @1 ]
set grid-y-inc world-height / grid-size-y m1 E+ e& Z! Z0 z
# p' O& C6 y! {8 v ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary; r6 n9 y: U/ w7 p! o) D
set acceleration 0.0994 ^' ^% u. x& }8 d8 C: b
end* c- M" T3 ^8 l8 O8 D) R
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
" C( ]" g' { p8 t* k;; and initialize the traffic lights to one setting
( }+ q: A7 e5 B" n6 M) Sto setup-patches& K. i0 [. C& l: C
;; initialize the patch-owned variables and color the patches to a base-color
" l) t4 b8 { M' { r ask patches& c* Z$ k) h- x! s
[
) ?3 ^9 w6 t7 j9 ^& t- {8 F' i3 B set intersection? false
5 f/ g* c4 t% a7 V9 ~, q' I' V set auto? false0 `4 H( W& R" b. I- h( O, i
set green-light-up? true. l3 {) g3 A& }* H4 ^0 L. N; ]2 Z) f
set my-row -1
& R% n) U% g# z set my-column -1+ y9 ?; l2 D& {: l; Y7 _
set my-phase -1
6 ` ~9 T! m! g# ] set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets- ~4 j! j6 U+ G% o: g
set roads patches with' o0 {! W, G! r0 l$ J9 l w
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or! R' b$ L+ v7 Q. Z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]( o, {1 ^3 z5 Y: M3 g) A
set intersections roads with9 c( |' g+ S' l
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and% S9 ^$ l1 }( s
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 v8 O* F! E T
' ?: F/ {5 c+ s; V' h" ] ask roads [ set pcolor white ]
; }* J. C5 B$ h& [: T/ a# }2 ~ setup-intersections) w( ~; A1 s% ~/ f5 ~! Y. a
end) Z3 f: N' t+ d4 F
其中定义道路的句子,如下所示,是什么意思啊?
& a, H: `1 J) r$ b% a9 o set roads patches with
9 v0 ]/ o+ S4 A w [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or# f% P% |1 W; g! b" v$ P9 y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
! x4 h' I/ ]: {2 B1 b6 s0 {+ X- G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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