|
|
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。1 `/ C, w2 ]& N% x1 V; S
netlogo自带的social science--traffic grid这一例子当中,
# g5 K9 q2 V4 i$ N1 \globals& l3 b2 V- }& W3 w7 \5 D8 C
[
) e- s1 w/ ^3 o/ c0 q grid-x-inc ;; the amount of patches in between two roads in the x direction
$ D6 I5 p6 @# I% l; g grid-y-inc ;; the amount of patches in between two roads in the y direction, J6 b2 H3 ] H: ^" T( ` I6 D
acceleration ;; the constant that controls how much a car speeds up or slows down by if
' j0 U! h2 c2 \* T, H2 c- M ;; it is to accelerate or decelerate
( x4 S0 J v& z phase ;; keeps track of the phase. B) j( J0 h. t" p& Z: A5 h
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure! H7 ]/ G H; ~; M: n; B/ j7 H9 t
current-light ;; the currently selected light5 S) R5 \9 H) ~" s6 |0 F
! L; s$ h$ R, e; u ;; patch agentsets0 k$ q: Z- J, x& M ?8 q' G; ?) z
intersections ;; agentset containing the patches that are intersections6 U1 q9 y4 ^: L! I. u, k j5 h
roads ;; agentset containing the patches that are roads5 n( X- r) B) k1 w/ V
]
* X5 s+ ^/ ], S3 n/ X# ] p. s+ f' [" {: \! H% G+ `3 `% r
turtles-own( O! d; b; r: T3 D% j
[
9 t/ Z& i6 x* f5 V speed ;; the speed of the turtle
- w# X! ~- a, X- [9 J up-car? ;; true if the turtle moves downwards and false if it moves to the right" O% h, {" J3 }; a. R( m
wait-time ;; the amount of time since the last time a turtle has moved- t! t# n8 ?7 H. p7 G% D4 Q4 q
]
4 g- E0 _ Y* B, J
3 a; w0 o* a. p0 F* Vpatches-own
/ A% z& ]* }* ]$ R& ?[
' \, }- ?1 f- J* n intersection? ;; true if the patch is at the intersection of two roads
+ y$ d8 ~# a2 f6 W5 {% w) E green-light-up? ;; true if the green light is above the intersection. otherwise, false.( r$ ]! D+ m0 Q3 f7 |! X# {
;; false for a non-intersection patches.
( |6 V% L( L8 ~) Y2 C) O my-row ;; the row of the intersection counting from the upper left corner of the
. v. t% r# J1 A" m6 Q/ y7 p; K ;; world. -1 for non-intersection patches.
% F$ }: D9 ^ H4 J: Q, X( p my-column ;; the column of the intersection counting from the upper left corner of the
4 O/ F" g# g; }$ M+ i0 T ;; world. -1 for non-intersection patches.
! ^1 W. i) n3 C my-phase ;; the phase for the intersection. -1 for non-intersection patches.
, T: _8 r( L& k' f/ T! {7 ~8 n auto? ;; whether or not this intersection will switch automatically.
5 C" a( n* f7 F3 R& W& Y. S& q ;; false for non-intersection patches.
/ k& |* N: d8 C( o5 V]8 Z9 l) V0 @/ { ~
; ]. P i5 _+ r3 w# d3 @& g: ~3 A
: F3 X" x% [7 w
;;;;;;;;;;;;;;;;;;;;;;0 r5 E4 V u' o7 u# }# z1 J) H
;; Setup Procedures ;; z; K; M8 x9 y$ `0 A9 @$ N
;;;;;;;;;;;;;;;;;;;;;;
- y* i5 ^( I/ M; T: M
; C. C( Z2 ^& e/ ~) }9 ?" f;; Initialize the display by giving the global and patch variables initial values.1 d/ D* F. C& A
;; Create num-cars of turtles if there are enough road patches for one turtle to% }. x6 t0 G& Z& Y$ a. g; C; y5 ^
;; be created per road patch. Set up the plots.
. \7 _1 y2 [. N) \- Nto setup* d V3 C' l+ O& y/ P6 q! S: ~
ca
- D4 k2 d1 N- ]* {/ \ setup-globals
# ]& x8 T! H) q& U& @# a1 h
% S2 \7 c! `5 m ;; First we ask the patches to draw themselves and set up a few variables% x# {, k) U7 [* i
setup-patches i. J/ F7 W. G; L8 _: v! o' O
make-current one-of intersections' A* d! H0 g% m7 P: M: |8 _
label-current
' [% E# ?) S( y* M8 g; g3 {2 |% l: U) o5 W0 r
set-default-shape turtles "car"
2 R" ?6 C2 F9 g, `' f. G- z7 W: c6 i7 K4 B$ X
if (num-cars > count roads)+ I7 B4 K) a# q. Q- v
[, p8 W6 ?) ? X- R) ?3 T
user-message (word "There are too many cars for the amount of "3 [$ K0 u8 r, l
"road. Either increase the amount of roads ", r7 B! g1 ~" z m( e @
"by increasing the GRID-SIZE-X or "
9 j2 @% l) K8 i5 \3 q9 ` "GRID-SIZE-Y sliders, or decrease the "
% o. U3 h" ?! J8 ?, r1 S* c "number of cars by lowering the NUMBER slider.\n"
) S! W ^" L% a. u9 [ "The setup has stopped.")' C( a! E: Z# p- U) `
stop+ g/ C! a. `+ F. ~ q
]! \8 O8 L1 J; Y" b6 D
- l$ e. @$ l! M) E: L8 C ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color/ O: K5 {( A* H. t' h0 O. \6 w- R
crt num-cars
7 w: j* d; D. F, ` [
, C; \; K: k: I, J" o4 m2 M9 V/ g setup-cars
# ^( ?5 o- c0 o* ]. x9 T- b8 w set-car-color% g- E4 t' y7 c9 r: f3 r7 G
record-data2 t0 z, {4 T" w! m1 n7 R
]0 c7 |. f H- t6 e& c* M; {( g
& g% I7 A% Z1 h2 x5 i, q ;; give the turtles an initial speed6 f" L5 |) I' l4 } o
ask turtles [ set-car-speed ]" r' b# x& e' Y
v% J1 t4 I* ^7 q; b. h6 b: o* Q8 r
reset-ticks
0 I* h5 N* ]4 B) iend7 N0 J2 |1 A) u1 J/ B* @8 v
. K% ?7 ]2 B& C;; Initialize the global variables to appropriate values9 {6 C; I+ [1 ], g, R7 q9 n
to setup-globals; ?: Q8 W, ^- K9 v
set current-light nobody ;; just for now, since there are no lights yet
5 v y0 G) ^- w+ B& P* n/ F7 { _ set phase 0
1 M3 [: ] u2 `7 M' e- {2 A set num-cars-stopped 0
7 a/ }- C- ?4 e6 k% i set grid-x-inc world-width / grid-size-x- j$ } i7 }( r7 Z% Y+ O) ?
set grid-y-inc world-height / grid-size-y* t* u( I' W$ o0 q' |
* l" t8 W4 g# B
;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
* o+ H- T8 p' y, Q set acceleration 0.099
4 V( A! o/ d9 Zend
& H: S M2 G% p+ }6 L: v
+ Q" I3 W7 o0 b p) ~;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
( Q) ~7 R5 l5 E! C$ O;; and initialize the traffic lights to one setting( Z+ Y& O9 ]" h: B4 }
to setup-patches
& D- r4 a; ^0 {$ N- N( h1 D0 \& b ;; initialize the patch-owned variables and color the patches to a base-color
' M5 B7 c6 T: f" Y5 L ask patches5 f* U; Z; L5 d" o- h
[
6 u: F6 Q: |9 I; b6 |' S" D set intersection? false
& Q, m, g) v \* d, Z5 F set auto? false5 f0 w1 J; n" S5 e0 j8 F# ^: T
set green-light-up? true v; J. L# g# B! L7 u9 T1 J! ^4 B
set my-row -1
' @9 j' u, k. ], e; b; g& S set my-column -1
! }; m8 _+ T9 b6 N set my-phase -1
. _& ]+ U; W( N) @ set pcolor brown + 3
2 x/ O; N# K0 y) k ]; c8 D! n) M) V/ n- d
. U$ [6 s/ V% Y' [# h ;; initialize the global variables that hold patch agentsets
2 I% b3 J0 F% S1 L5 t set roads patches with
1 z( z* @7 ?2 a) B2 ? [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or5 U# n6 ~/ x3 \! {) v2 V' G8 z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
t) C8 O. W. R# }. K set intersections roads with
0 L- z# S- ]0 n- H [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and0 a+ }1 C+ |- h$ d! \
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. X7 S3 p; F8 R; Q* f& Z2 j
4 v( @- \" o) \ ask roads [ set pcolor white ]! r' A* B m3 c
setup-intersections& E: g. X# p/ D7 K/ L
end; S0 c# T9 q, u
其中定义道路的句子,如下所示,是什么意思啊?
6 i2 t% I, u: j0 Y/ U8 m3 Q6 Q. d set roads patches with. t2 W, k J0 Y9 A( ^; }7 ^0 e% Z
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or6 r' K" m' ^; m! L" Y. t
(floor((pycor + max-pycor) mod grid-y-inc) = 0)], x A0 b) c: r5 Y; E) e& X
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? |
|