|
|
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。
- P3 z g; g# t7 H4 Mnetlogo自带的social science--traffic grid这一例子当中,* Q2 }2 V6 \) ^( g" y
globals
" g# K$ d& u+ w# e/ h* L[0 I; `2 y, c! U+ C
grid-x-inc ;; the amount of patches in between two roads in the x direction# {( q" q" f( F6 L$ v1 b( g
grid-y-inc ;; the amount of patches in between two roads in the y direction6 n! J# B1 r% D% v2 u" p# t
acceleration ;; the constant that controls how much a car speeds up or slows down by if
2 q4 L* p& D; Q' U: L# g0 A ;; it is to accelerate or decelerate7 L5 G" r6 y* R' n. J
phase ;; keeps track of the phase
3 ?8 I# O# k! |7 F num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure) r; p1 R7 H$ x$ y& M) M1 l4 d, Y
current-light ;; the currently selected light& |( m4 \! ^% v4 j1 U4 Y3 t. \0 b
1 q1 t* o; C4 G
;; patch agentsets
8 @' O3 w! p. c0 X" V! w# R intersections ;; agentset containing the patches that are intersections3 |% t* Y, h3 H" U {; L) l- d
roads ;; agentset containing the patches that are roads3 U& z3 e' H0 F! f; j4 }% j
]
2 P8 A x8 i, B9 L) L0 s6 H; @
. b" a+ V+ _! b. M1 Z, ~+ ~ ^) d* Bturtles-own4 D! ] i4 t' R. M
[' I: a3 F! ^1 L
speed ;; the speed of the turtle" ?* o0 W s, H% f' ^3 R0 c, V
up-car? ;; true if the turtle moves downwards and false if it moves to the right% Z7 Q+ }+ m# Q& v* H s
wait-time ;; the amount of time since the last time a turtle has moved
+ w, x5 E/ \0 J: N8 j+ S% R- {]+ s! {5 b$ {$ {, P/ A2 o/ l
& g: z6 B' T6 P- R4 ^. q, Rpatches-own2 Y* M7 b1 K6 Z! u
[
3 x0 X, R, w1 m4 C intersection? ;; true if the patch is at the intersection of two roads6 s9 T$ H4 t7 m+ U+ M' T) S6 i* ^* K+ W, ~3 V
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! | o7 P3 Y/ L ;; false for a non-intersection patches.
8 a/ r2 @ m2 H4 g2 A my-row ;; the row of the intersection counting from the upper left corner of the. Z, [8 p# D. O+ L5 P1 r& G
;; world. -1 for non-intersection patches.
4 ~. d% l! Z6 I9 ~9 k! J my-column ;; the column of the intersection counting from the upper left corner of the t& `- \7 {1 [, d* P7 J/ L
;; world. -1 for non-intersection patches.1 ?4 U4 b& W, i5 U% D, Z
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
! L9 ?7 R1 G" ^# L2 ^ auto? ;; whether or not this intersection will switch automatically.& o: Q4 Y! L# E" x
;; false for non-intersection patches.7 F$ H6 T: I: d0 {* Y' E
]
# [- f# e# f; R/ w; E M5 |/ ^
2 C8 ~- ^- y; z! Q9 {% x6 T' }8 W# B
;;;;;;;;;;;;;;;;;;;;;;0 n7 {* M V$ Q& Z% j i
;; Setup Procedures ;;$ x* q2 p0 Z# O- o" r, p3 _
;;;;;;;;;;;;;;;;;;;;;;
+ \! y% @! e" b5 Y; M& R# C2 i) W! }8 j6 Z
;; Initialize the display by giving the global and patch variables initial values.
: n" x& O6 A: A) k;; Create num-cars of turtles if there are enough road patches for one turtle to8 Z' E' ]# }$ M: V% ~* y- z1 x
;; be created per road patch. Set up the plots.
% _( z" E8 n" I$ @. Q5 l# ito setup
! X, C( w: t2 ~/ v& K' ?9 T( ~ ca
5 Y/ B$ M& s6 c( q' J2 e5 `( z% m setup-globals
/ r Q. L8 S4 V* {
: r8 T$ m# [' k1 q; A ;; First we ask the patches to draw themselves and set up a few variables0 x* s1 O! ~+ W5 L4 U2 A
setup-patches9 m$ x! i+ H9 h4 |/ \- J; B1 ^- C
make-current one-of intersections! {' `/ D* Z7 D
label-current
5 H9 |, K5 Q* T) T2 A. ]1 j$ z) t- B3 i% O; ~5 H8 i
set-default-shape turtles "car"
8 E" z$ l; t, [3 k: `' l) a4 x: a! u; L# O1 n: \( }: }; ^
if (num-cars > count roads)$ X, k: i) l" G# O) o2 F1 ~
[
- E3 j3 m: I4 }. a user-message (word "There are too many cars for the amount of "9 D% ^1 c+ m0 \( o: U4 R
"road. Either increase the amount of roads "
" m8 A; \% ^& [ "by increasing the GRID-SIZE-X or "4 K* I8 D( \$ X9 ~, ] Z
"GRID-SIZE-Y sliders, or decrease the "# G1 d/ B$ E# y& b; E
"number of cars by lowering the NUMBER slider.\n"
8 f1 D, O1 X* @7 }& i5 H "The setup has stopped."); G# y M+ v0 ]: `' l
stop8 y9 D1 s2 y& m) `( s& a
]8 v- \+ {: g2 q0 s( V
; f8 |8 e( z0 w% ? ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
( G3 E9 j- W: H crt num-cars
; e1 a, W9 V/ r( o* c [
9 Z8 G4 Y- J) ]8 u1 s setup-cars
0 o+ ~4 Q- f& R+ M5 O6 p set-car-color* ?0 X1 c+ j3 L# K, E
record-data6 H4 x* M n6 c0 i! Y+ n w7 b
]; n, U; u0 [' ]/ i- ~5 \5 z: N' m+ E
5 {: n- c- [0 x/ ~8 l9 v8 p
;; give the turtles an initial speed) k9 X# N& o( W+ Q( K! K! H
ask turtles [ set-car-speed ]7 d1 y. o# Z; |% X0 ^* W% l2 n! I f
$ @$ s5 [- k! Z9 C+ W$ ^4 ^# r reset-ticks
+ N Y1 ?/ \% e, R7 Z( hend
) E: ~0 x. C2 M0 T
; a/ [, @+ E4 B# T' K5 o' R, H;; Initialize the global variables to appropriate values9 U4 n l+ m; O' E* L' x0 f
to setup-globals+ W: G3 P: T1 C- T6 g: M
set current-light nobody ;; just for now, since there are no lights yet
% N5 [1 H$ w% C- |* l' N9 ^" N/ g) o set phase 0! J6 n) u7 U5 g- z; h) |
set num-cars-stopped 0
* j" k, z s$ m. ~# ~6 N2 m' N% h set grid-x-inc world-width / grid-size-x
; ?$ k3 C. i6 S5 Q( R) K$ s( C set grid-y-inc world-height / grid-size-y6 @, M. I; [) o* z3 `- Z5 [
1 A" {) v" ?* |/ i ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
3 Q/ ] T2 o3 w% w/ E set acceleration 0.099
- ? ^7 b" ]* ?- c+ P& S2 Mend
/ X4 a. W" z9 x% L
, }7 B; K) t4 C! w8 `$ c;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
1 Z( l ?7 ~. D2 m0 U- { s;; and initialize the traffic lights to one setting
# g7 h/ c+ Z% ]+ y m/ [to setup-patches5 @; v8 D: h# t
;; initialize the patch-owned variables and color the patches to a base-color
- L% l4 C! M& ]( p ask patches
9 y2 |. z' k: D1 X9 b' o [# m+ z [
' F2 [3 d6 {9 c2 B set intersection? false1 l0 r+ D4 w& T4 S3 k
set auto? false
* r+ k4 X- v# o- m% V set green-light-up? true
1 y8 X0 U- ]: A: _9 P0 P$ r7 O set my-row -1
& J5 h! o( C9 W& u: R6 Z$ Q set my-column -1- y8 ] N4 Q: M) |+ X+ N
set my-phase -17 W1 D3 m. V& u1 P3 ?# F
set pcolor brown + 35 s, i6 o0 |( x( }. I3 Z
]+ A& B% S8 v' z* F0 n, b
- R: m6 @2 H: X
;; initialize the global variables that hold patch agentsets: W7 q# n1 Q. q/ h, _0 k
set roads patches with7 L0 o( V4 z# p: K/ w9 S
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 U% d/ d6 B# g& p. \5 o (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 a8 b T, c1 l9 l+ A+ D set intersections roads with
' l7 H- R5 A) H [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
% e( g4 p8 m8 D6 N, H0 A (floor((pycor + max-pycor) mod grid-y-inc) = 0)]: c* d. U5 a( \2 P( g4 @1 K/ l9 q
* d8 }9 ?! {0 g5 ]8 O! H
ask roads [ set pcolor white ]: s; c5 i: u, d+ T8 Y, a
setup-intersections4 E# Z ^: P; u _$ C" k$ ?. l( g
end
, n- Z& J1 Q$ w' m# G其中定义道路的句子,如下所示,是什么意思啊?& [% C9 m! V4 P5 R3 c
set roads patches with# @! \6 M2 {/ S9 X9 v* ~
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 I, ?, X6 K; h/ T (floor((pycor + max-pycor) mod grid-y-inc) = 0)]& W; d6 `% `1 k+ `8 M# z1 ^
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? |
|