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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。
: Z8 A+ @/ n4 V3 F% enetlogo自带的social science--traffic grid这一例子当中,
. H# \! N, _) i. u. jglobals
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) ?" O) B. }- y! n5 W0 R6 Z grid-x-inc ;; the amount of patches in between two roads in the x direction
) L+ K1 M6 [! e1 W# ^ A% G7 R grid-y-inc ;; the amount of patches in between two roads in the y direction. F# W$ N7 B% w% f4 O: B
acceleration ;; the constant that controls how much a car speeds up or slows down by if
& z& y z$ t! Z* ?1 @2 D ;; it is to accelerate or decelerate1 K8 }7 Q4 s( e! |1 O
phase ;; keeps track of the phase
' ^7 i8 G" |! n" F) w* ^" k* E num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
5 e# \ Z8 O" z8 f% x) t: B current-light ;; the currently selected light: ?& ^* J9 t; _' {
% F1 m) q+ s0 O ;; patch agentsets
3 B; Y& h2 N4 [) ^: ?& S/ i7 e intersections ;; agentset containing the patches that are intersections O N2 i; c4 J; u' V* l
roads ;; agentset containing the patches that are roads
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turtles-own j" S {1 g* K# i2 N1 X+ K. r. |
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speed ;; the speed of the turtle
( E0 |" w& r0 G' X% Q3 u0 X( s up-car? ;; true if the turtle moves downwards and false if it moves to the right1 {8 P: t3 {: x8 O$ ^% \
wait-time ;; the amount of time since the last time a turtle has moved' o' ~$ Q: n: T- M9 ^
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads
! L* G, _0 \, ]0 i$ ]: j. w2 s green-light-up? ;; true if the green light is above the intersection. otherwise, false.' e" W# j7 A7 _) N
;; false for a non-intersection patches.% M: h$ E2 V! Z$ i; x! U. Y
my-row ;; the row of the intersection counting from the upper left corner of the
# h3 N7 f6 C& F* z7 Q; C+ i2 r( Z ;; world. -1 for non-intersection patches.
: @2 H( i1 P; G my-column ;; the column of the intersection counting from the upper left corner of the
* k0 P6 y. D8 V" v' k6 l! u ;; world. -1 for non-intersection patches.
% {1 I4 }/ A+ n, W3 N my-phase ;; the phase for the intersection. -1 for non-intersection patches.
" i; y4 U! f% w; Y0 o" X! A: h" p; U auto? ;; whether or not this intersection will switch automatically.
7 g v8 }0 I- U. |! x- F- `* d" a b& h+ t ;; false for non-intersection patches.
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" H% u8 l @9 b# L5 |;;;;;;;;;;;;;;;;;;;;;;6 @( u1 O) Y& N; H
;; Setup Procedures ;;3 ]0 j$ j$ s/ |" ^3 l
;;;;;;;;;;;;;;;;;;;;;;9 L/ p7 T; _; h4 n6 L% m9 V% W& T
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;; Initialize the display by giving the global and patch variables initial values.
i& s! c8 \ ]- O: e1 | l;; Create num-cars of turtles if there are enough road patches for one turtle to
3 h1 a) `$ c" W5 s5 e;; be created per road patch. Set up the plots.
7 A8 O9 G/ e0 `; ^3 Eto setup
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setup-globals6 }3 `! a6 _6 `% i7 u" B
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;; First we ask the patches to draw themselves and set up a few variables
' B# C4 N' ~1 L7 u setup-patches6 z3 s0 K# |1 F3 m/ V+ ]9 y
make-current one-of intersections( @ ~3 P, e% t3 E( l- Y
label-current
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set-default-shape turtles "car"- z1 z) h, D- t9 l
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if (num-cars > count roads)7 z/ o3 `) | k& H5 k1 z7 v
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user-message (word "There are too many cars for the amount of "
( W7 }5 f, B& R, @5 c9 I O1 E "road. Either increase the amount of roads "
0 M+ L- A3 Y* v "by increasing the GRID-SIZE-X or "
2 A% B- |& ^* d7 D' B0 j "GRID-SIZE-Y sliders, or decrease the "- E9 j4 P( x4 ]1 w& d6 m Q [
"number of cars by lowering the NUMBER slider.\n"% U9 B0 p& `* n" G- |+ ]
"The setup has stopped.")
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
# f' z6 Y% Z6 u( G) p8 L. P2 Q0 r crt num-cars" x6 W4 {! T) S3 o. v. D
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setup-cars
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record-data
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;; give the turtles an initial speed
& w* k4 ~" C; S; K+ e( | ask turtles [ set-car-speed ]# W9 Q" }# ] i3 Y8 s' ^8 k ^4 Z
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reset-ticks
2 r+ K7 l f7 G3 i6 M3 |6 X/ q, nend
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' V1 h9 c& c0 U Z% i;; Initialize the global variables to appropriate values( r) j' K. U) S; I, l% h
to setup-globals
, j \9 {3 e! P% T* l- k set current-light nobody ;; just for now, since there are no lights yet0 h5 t, o) T' Y9 z7 R9 O4 n
set phase 0; A! G# [# ]3 l- r9 }( c+ V* u% N
set num-cars-stopped 0
. h% s. `2 B$ m set grid-x-inc world-width / grid-size-x
/ j3 G' C& C& L set grid-y-inc world-height / grid-size-y
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) V! X5 y& X# `8 f9 v ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
8 k7 K- \, l0 U7 n8 `8 Y% ` set acceleration 0.099
5 U; P; Q; u5 G& d- e% m; kend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,8 O/ [9 p6 ]" W7 I Q+ M
;; and initialize the traffic lights to one setting4 {: S% O7 f" R9 j
to setup-patches! t+ T% l" v; X9 F1 U, V
;; initialize the patch-owned variables and color the patches to a base-color) a2 d" Y! X& m; M8 v
ask patches8 N- K$ [- B! d- C/ s
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set intersection? false5 n& C$ J) n% P. J( M/ }# Y
set auto? false8 W) ?0 c8 f2 J2 S
set green-light-up? true( `9 n7 o* ^& N. n+ d$ ^; i; N& c
set my-row -1/ e( M3 c: O* A. w, A
set my-column -1
! C4 S1 \( }* a) j; M+ J8 C set my-phase -1
6 ^. C- V Y$ \ set pcolor brown + 3
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% r* T% f, q( V2 s0 I3 R ;; initialize the global variables that hold patch agentsets2 b0 U; _* ^) S6 W6 N
set roads patches with" s7 V R' H1 |# l8 }$ _1 v
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% q1 G- @- e; Y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 V, h+ N0 O4 p$ Z; N$ x! `0 u- L; ^
set intersections roads with" b5 Z* G" \- q/ U/ Y" B
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
' J0 R9 E+ }& d- ~ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]8 ]' x$ E; Z) _
setup-intersections$ H% x+ ]& I M1 Y
end% A, j- d8 k' u! C4 J2 |0 I: J9 }
其中定义道路的句子,如下所示,是什么意思啊?
$ ]" o0 r/ k; L" l set roads patches with
# t- S/ B2 M L- L/ `2 }0 | [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
3 z+ \% [0 h$ e2 W3 x (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; ?% t1 H& [% 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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