|
|
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。
K* o$ }- F D9 Znetlogo自带的social science--traffic grid这一例子当中,
4 u! s! O* v, Z4 P4 oglobals
! N% F7 G \& h* b( N( h. r( {[5 e5 H! u4 B- [
grid-x-inc ;; the amount of patches in between two roads in the x direction: V3 Z6 L# r5 M3 ?
grid-y-inc ;; the amount of patches in between two roads in the y direction8 K& E7 F2 @. H" r
acceleration ;; the constant that controls how much a car speeds up or slows down by if1 k6 V! q! x# n$ P
;; it is to accelerate or decelerate2 G6 Y7 o- q( A2 b5 I, u
phase ;; keeps track of the phase9 ~' j: y2 m( x5 V
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
: {! S2 E1 q7 ~ current-light ;; the currently selected light. ]2 C# r8 C# s7 c
. N" S/ s5 j8 L* \) Q& j
;; patch agentsets
) ^) m/ ^) L6 h+ J+ U# N intersections ;; agentset containing the patches that are intersections! n4 ?9 c8 [2 ]! ]# |( M( `
roads ;; agentset containing the patches that are roads
, z5 v! u6 h- z' A/ j]. H' ~1 [/ p! ^# J
- a8 P1 S3 \& C* ~
turtles-own: `+ P: g% f1 Z2 o
[ C1 g; G3 g. K9 E! b G6 U6 N
speed ;; the speed of the turtle
& l* h0 g4 {' ^& r. I5 c& p/ B up-car? ;; true if the turtle moves downwards and false if it moves to the right+ R; E5 U7 N7 e! b7 V% h/ Y) @4 |
wait-time ;; the amount of time since the last time a turtle has moved
4 q- k3 @7 B3 ~: o], D, }5 L2 t5 ~3 s, l h
! T+ }3 }- z6 ^0 U8 L
patches-own6 \5 N: H) y. V' @; B0 S- b
[4 C- J$ j z% i3 d( u. W, L
intersection? ;; true if the patch is at the intersection of two roads
2 {; o1 b3 ?9 @, ] green-light-up? ;; true if the green light is above the intersection. otherwise, false.
@) u3 N' R; k ;; false for a non-intersection patches.
, P# u, n G" \/ P0 V my-row ;; the row of the intersection counting from the upper left corner of the- }6 ?% q) N4 W
;; world. -1 for non-intersection patches.' ]) v Y, r! `0 t
my-column ;; the column of the intersection counting from the upper left corner of the
5 b/ {3 o7 ~3 ^8 B, M5 m ;; world. -1 for non-intersection patches.2 T% O5 }& y- N, o% m0 M. F
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
A, W O# R" {9 B: }; i auto? ;; whether or not this intersection will switch automatically.5 `& I' \9 O8 A0 @
;; false for non-intersection patches.
9 R" v+ L9 R2 v" U/ C/ d u1 W# t]1 R' ~& `: N& {. o- }3 D
8 P8 P6 M5 H# f6 \8 z' J3 E0 c) ~% U5 s( q }' ?7 y$ n
;;;;;;;;;;;;;;;;;;;;;;
- l* K" R5 H% Z% @3 e;; Setup Procedures ;;
, \* B5 e0 c& q7 u; s;;;;;;;;;;;;;;;;;;;;;;
0 Z/ T. n, J5 o" P4 z6 o) J. n% [ x' u( F$ Z; t* p5 M
;; Initialize the display by giving the global and patch variables initial values.
. r2 ?6 n) e0 p1 u" j5 F1 V;; Create num-cars of turtles if there are enough road patches for one turtle to
y0 o/ O. @9 ^1 a4 ~;; be created per road patch. Set up the plots.
( Y# Z# g$ E* q7 a: q+ _to setup
! a( G0 ~# V0 @; d, \ ca/ j2 g6 ^; Z5 d: R) L# g2 G
setup-globals
* _( {8 f( d4 f8 Y
# |! P; ~; d/ H7 P4 ^! s ;; First we ask the patches to draw themselves and set up a few variables: \( Y( o+ g3 a0 y6 ~9 a( |
setup-patches# _" N; T# M+ z
make-current one-of intersections; q7 p) d3 ]2 s. n9 k0 b
label-current% F5 D5 I; g8 D3 ^9 ?
; u1 g" A0 e* Q+ v
set-default-shape turtles "car"
8 ~- i) g/ Q* A
. L5 W/ s. S6 ~8 W) g; C" I if (num-cars > count roads)& D; m, K# v9 A! C4 a
[
& z9 U; N: ?9 ?; k. I+ _: z6 S4 C1 p user-message (word "There are too many cars for the amount of "' V3 A) H5 q8 S% R
"road. Either increase the amount of roads " }# Y4 _5 D7 ^/ \' @
"by increasing the GRID-SIZE-X or "
7 d6 c+ X, w3 a2 |3 m) F! k# g5 T "GRID-SIZE-Y sliders, or decrease the "
9 m: F; }: x" h1 f E "number of cars by lowering the NUMBER slider.\n"
5 R* ~" i* J& [ "The setup has stopped.")
% H$ v5 v0 A% F" Y% Y% |: Z/ i+ Q9 p stop
$ K/ f) z6 r }7 p9 R9 E ]
: Y7 U% u# |3 p
- [# Y1 X0 d: ~$ Q5 g) R ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
0 X4 f7 S% q; w crt num-cars
. M( J1 [9 E/ Q6 Q; i" b [
X; f# t& X. r% v setup-cars
: w9 N$ I& t4 k q1 W; p! h set-car-color
3 R, g9 _8 m7 D9 H record-data
" ^2 D7 m W! | ]
3 b' U: O' R2 V, w3 t# v; K0 g; k. m7 c& Q1 v
;; give the turtles an initial speed
5 |: t; o2 B8 n/ X3 ~2 z ask turtles [ set-car-speed ]
7 b1 `. W1 D# K+ ~( u. n' X& j) f% F7 M5 O/ c
reset-ticks& G* j/ P' W8 A7 w c
end
' p& V, u8 A1 Z0 u% \ \% o* G" u* i8 E; V' F. i3 E
;; Initialize the global variables to appropriate values
' Z& B) b; H1 u3 E ]to setup-globals' Q \- y c9 `3 `; u1 X6 O
set current-light nobody ;; just for now, since there are no lights yet3 L" W/ x6 h$ t- }9 T6 }
set phase 0' n$ R; p- F8 r" x0 @2 W4 y7 u' R; p
set num-cars-stopped 0
' T8 y" w2 T. {9 p* ]/ Y2 ? set grid-x-inc world-width / grid-size-x
% p% q( Q, S6 b$ R+ X set grid-y-inc world-height / grid-size-y( X4 r F S' U" D
% F) P. V, m) b5 C1 l ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary! G6 Y' N/ M5 j$ q6 K6 F
set acceleration 0.099
) L( \; J$ G( U2 U( oend
/ h) C- X7 |9 Q3 s4 ?6 H% S7 h* G! y2 i t
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
# ]0 x9 \. G+ p9 i4 |; |; O3 K# ?;; and initialize the traffic lights to one setting
' E6 G) P" x% U' o) w- \9 ~to setup-patches
+ F9 @$ e8 M; {/ R6 n ;; initialize the patch-owned variables and color the patches to a base-color
; z( D$ P* J, X6 N( |, D$ { ask patches
5 q3 h+ `9 c$ O$ q$ H& ] [, [& G, p, y. Y/ G# H6 ?8 G
set intersection? false- a6 j; p4 S* C3 s, S) x0 ~
set auto? false7 z4 p4 {3 m8 E, \! X
set green-light-up? true
5 Y2 C9 l1 c/ X, z3 w set my-row -1
' V# O$ g; z- y a$ d/ N. E set my-column -14 X4 [/ A+ F: g3 N% n
set my-phase -1' p% G# g/ d4 e% G) M
set pcolor brown + 35 o X2 d7 q. Q
]0 |2 y7 [) D* P) D- j" Q' Y
* Q$ U' o* J3 ~8 X" P
;; initialize the global variables that hold patch agentsets M9 q9 g) ^4 U3 q9 s. D) ]) ]; N
set roads patches with
% ?2 o" H$ p7 h1 H+ U [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
9 P8 ^8 I$ `" y: I6 p (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 m) o& R* K- b0 Q; @) d set intersections roads with m) s& h9 n( C& q1 j$ J
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and) j G& h7 H9 M7 P& |, L( d
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]- j( i$ s3 Z1 d" `7 c& J0 K6 ?
4 ]; g8 G; M; j1 K ask roads [ set pcolor white ]" Q7 _6 d7 @% ~* B
setup-intersections) S; M6 l) y1 M8 R; B) x% g
end" e- R* T+ \2 M6 M& E" B; E; f
其中定义道路的句子,如下所示,是什么意思啊?
. x0 |2 W. P. r# }( ~0 `7 U3 O set roads patches with) u1 z$ P( X$ [3 B
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or- a4 U2 M4 ^4 e% v, Y+ \
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 \0 Z I' y4 P \
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? |
|