|
|
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。) E6 R6 P8 v: q) {4 T: K5 m- D
netlogo自带的social science--traffic grid这一例子当中,
/ m. \2 q/ T( S0 S" y; w$ ]# ]$ Aglobals
1 U& o1 W( b D[7 a5 U8 E7 z0 S$ R5 x/ K
grid-x-inc ;; the amount of patches in between two roads in the x direction
0 R1 V7 K( L" [1 V5 K grid-y-inc ;; the amount of patches in between two roads in the y direction
) |! k0 a/ ^9 { acceleration ;; the constant that controls how much a car speeds up or slows down by if; s8 ]; n) F. F& Q, }
;; it is to accelerate or decelerate
3 s3 ]9 I( j6 U2 a phase ;; keeps track of the phase5 [0 b+ U, V& _
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure* @5 C. J% H& _9 M# m7 \- c
current-light ;; the currently selected light
3 Q4 A, C5 E/ I) Z. }6 ]% z& v, g: W+ x- [
;; patch agentsets# P5 q! r' D. y" h/ M# x
intersections ;; agentset containing the patches that are intersections
a6 z, B6 I, Z N. F roads ;; agentset containing the patches that are roads
4 E6 ^: u" V, x* `8 c3 i]( t" {7 J ]( G- m
0 S3 Y* E- u3 ~6 d; nturtles-own& M/ ]0 I; g2 r, N1 e
[
; J" q9 Q; d7 p speed ;; the speed of the turtle
1 b7 K& O( j9 ]7 X, c, p up-car? ;; true if the turtle moves downwards and false if it moves to the right
/ c! ^6 s! M( Q wait-time ;; the amount of time since the last time a turtle has moved7 |6 v; L. q" U: Y$ G
]
2 r) ^8 c3 c0 D( X- `, G* S% z
9 b' s) [: J O. `0 }patches-own* i3 W- }% y6 H$ m% X+ Z
[% P) c- ^- b7 v$ A1 T8 n. ~
intersection? ;; true if the patch is at the intersection of two roads7 |+ X. \& s3 n- R" r
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
4 ^2 n# C5 ?' S- x5 ?- v' F6 y7 { ;; false for a non-intersection patches.' D6 W* Q# u+ \: \; N2 \
my-row ;; the row of the intersection counting from the upper left corner of the' r- S( X: y a
;; world. -1 for non-intersection patches.
3 Z3 r6 i# j, ]" T3 k9 { my-column ;; the column of the intersection counting from the upper left corner of the
: g2 ?" `/ s; \- A6 V, j8 L* t) E ;; world. -1 for non-intersection patches.# h6 `2 l0 W- K' m) _0 \1 b
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
7 }* W6 `( L6 Q$ t auto? ;; whether or not this intersection will switch automatically.
* c0 G* X1 m- |) A- m4 ^ G/ ?7 Z ;; false for non-intersection patches.
, H$ c6 m( b9 A% }( k]
6 i) Y$ r9 u4 s$ E2 M( J P p3 {" D* v. Q, G# G# ~
2 r2 j5 w2 H) g4 I! _6 C2 e5 D4 ^;;;;;;;;;;;;;;;;;;;;;;
: X3 i; |+ R' }" a: a;; Setup Procedures ;;
: ~0 E) z# ^" Q. @; P;;;;;;;;;;;;;;;;;;;;;;9 t# Y% ~ D8 [9 J. c' d
) h: K' C$ m* T& s1 P;; Initialize the display by giving the global and patch variables initial values.) m6 V' }& G3 U" h
;; Create num-cars of turtles if there are enough road patches for one turtle to
5 {& L- |2 \: v4 e ]! [' A;; be created per road patch. Set up the plots.
! U# X7 l( e+ B* |/ p9 V1 Sto setup$ B3 n. q: [9 b, l
ca' g- J4 ^" S; F+ {' X. [
setup-globals$ v: s$ A9 {7 V; E
, B) ]0 A* i: L& i/ @8 h3 b
;; First we ask the patches to draw themselves and set up a few variables
7 g9 O7 o. c$ v/ v1 f1 K setup-patches3 W* X. {" q# F% h6 B
make-current one-of intersections
% f' o/ w, T5 K4 y4 q/ b% y8 `, C& l label-current
- h c* f# t8 ^9 V. o+ c
^9 w8 { t s6 r" V: t9 x7 S set-default-shape turtles "car"
5 R0 P8 g% v3 J
- k# Q1 R( j+ P1 u- d if (num-cars > count roads)' t4 e% q( e" E- G
[
+ y8 Y `% }2 H, K/ m1 ` user-message (word "There are too many cars for the amount of "
5 U, w% {, C9 _, H "road. Either increase the amount of roads "- Z- @3 r' T% \
"by increasing the GRID-SIZE-X or "
. F0 \1 [7 z+ Q" n) q; C "GRID-SIZE-Y sliders, or decrease the "% k& {8 x& p6 _5 x- g
"number of cars by lowering the NUMBER slider.\n"0 F+ T3 h& ^" o7 B: D# }, C
"The setup has stopped.")
* Q) k, [% U; H% S4 b4 o) w stop
+ f( F4 Y) f4 E6 L# f, V8 x ]
@* C: d6 S5 Q0 s
! y, |/ S& n3 Y$ d$ u ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
2 G( U4 s7 C/ |' V crt num-cars8 d0 @( {$ b0 |1 r/ p' p
[1 o) U6 P' h& Z2 j+ l, f1 Q! Y) H/ W
setup-cars
: }3 S& u, @ x5 T; [+ A3 H w& | set-car-color
6 C+ n. t- C9 V0 b" [ record-data
/ E W$ C" H, }. x ]) W# `$ S: j7 o% p7 ^; u
7 m& |9 E: w- u) z% U) e
;; give the turtles an initial speed4 A+ y1 u5 D( e K) u( k
ask turtles [ set-car-speed ]4 _+ V* |6 ~5 W+ ], M& G" p2 V
/ L/ V" C6 d9 f; q6 x" V reset-ticks) G+ r4 C4 f C! R9 z* ?
end" H) T# t- z: r0 v' s
! g, `! C: y8 n! ?1 e1 G4 N;; Initialize the global variables to appropriate values
7 v# e, u; ~$ D6 Qto setup-globals2 E/ R+ A# P* B& Y# h
set current-light nobody ;; just for now, since there are no lights yet
* p: O' c* r: C; K+ ]! F; w set phase 0
/ C; @. Z5 a2 j) m( ~ set num-cars-stopped 02 }! m3 x% S+ X* \& q/ N! [+ Q
set grid-x-inc world-width / grid-size-x
: L/ g! z2 p4 ?- g& j( r. @- k set grid-y-inc world-height / grid-size-y
/ b9 I- W4 k& o0 d* i8 ^( K% O
0 f) N" _* B) j) H0 m Z# w ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
% s+ s) y! `0 h+ Q. C set acceleration 0.0996 e& F0 P$ H: ?7 J+ Q6 a
end
3 F# [8 G) V O5 c0 |; _$ `
6 S: X& Z) n) F$ c;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
" @$ S! M e; ]4 N- c$ W2 D;; and initialize the traffic lights to one setting
' s- {) k- T1 ~" Jto setup-patches
" S7 q: f0 Q3 O$ x ;; initialize the patch-owned variables and color the patches to a base-color. g+ k- |7 q( y( V
ask patches
$ R$ d5 K* @4 S4 X& |. [ [
6 ^: z" S2 `% _- V. s# ~$ ] set intersection? false
6 n7 `8 p5 r/ H* w set auto? false" `8 a9 E6 z2 U) q7 `$ O4 c
set green-light-up? true; G: ^' h3 n' @' J
set my-row -1
% V. I2 d. _5 _- g* o set my-column -1
( S( V" \, T- d$ u: q set my-phase -1
$ F" K0 U2 J! A2 ]( Q set pcolor brown + 3
# B: Q4 i ~4 U4 I( g0 {( p ]
3 i4 S. ?5 B- \4 c8 r; j( y: z+ l2 Z! _- [5 ^' e5 x" x
;; initialize the global variables that hold patch agentsets$ l% h. {5 q% |) n
set roads patches with/ _' b( B& G% @& T' T! P6 V) L
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or* D+ v" h$ y2 C$ m. R: n
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ v; v& P& W/ o) s
set intersections roads with5 Y" C$ W* U3 n- a) B
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and' \8 [' D2 m3 t6 y& y! R" H
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 }3 g4 M2 C7 D( e; {
1 C- B& _7 j6 u' ^! d) `8 K
ask roads [ set pcolor white ]( F. c: Z/ y- q9 q! L9 M" J2 g/ ^, z- m
setup-intersections
5 D& b( W- q6 ?% W6 z" }, z( H( S. Zend4 [0 C( I [+ e) W+ S3 ?
其中定义道路的句子,如下所示,是什么意思啊?3 m- E; K1 r+ M! R
set roads patches with
% J6 k# G& C/ i& _: H/ v( i9 W [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or+ T- l. N5 ~, k9 ?6 g6 Y8 G. W
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 E0 H. W7 c# C1 ?9 S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? |
|