|
|
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。) V. j( i' D; z: A, G: }- ~, h m7 `
netlogo自带的social science--traffic grid这一例子当中,
" d. I( x& Y" _3 Fglobals( k; m5 `$ `8 m# ~1 l6 z
[
+ V# `% h; J* h% s+ c! c grid-x-inc ;; the amount of patches in between two roads in the x direction
2 }) P3 |! k& Z0 g grid-y-inc ;; the amount of patches in between two roads in the y direction
" q+ ~! i0 N% U, r. D/ \' _ acceleration ;; the constant that controls how much a car speeds up or slows down by if
# V! H. X9 Z+ u' j6 x/ U ;; it is to accelerate or decelerate! ?1 ]1 Z6 [( F1 K+ M5 \, O! R& ~
phase ;; keeps track of the phase+ p% Q. X2 K7 m+ ~# Y% j
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure8 f9 V4 X8 \+ c" o& Y4 x9 y
current-light ;; the currently selected light
+ F T( d0 ^5 I+ G, S/ m* K. y/ O9 p! E% W9 B5 ^+ ^- {! U4 P+ ^
;; patch agentsets$ Y5 b% \+ `( q: a
intersections ;; agentset containing the patches that are intersections O6 k* D, r5 E& l/ O7 `8 r
roads ;; agentset containing the patches that are roads
5 v! E' P$ \* i% h& b; ?& d* F]" p8 N( ]6 R9 p5 s% f
+ E: W5 U3 b1 n( a4 s
turtles-own
, s5 w: M' ~$ X! Z[! _* ]& u! p* |- \' j, k
speed ;; the speed of the turtle
* y# _" f2 J9 f7 K up-car? ;; true if the turtle moves downwards and false if it moves to the right
% \+ z$ x1 h! W3 _2 F5 M6 |, g wait-time ;; the amount of time since the last time a turtle has moved
_9 k0 Z" k1 a0 Z]+ ^& u5 E! i$ l1 s% }
5 w, q0 r! ~) ^& U* Y
patches-own% `: z' N9 N5 E9 t* l$ n
[
4 l2 F& E# C. `# n5 m+ z/ ]: r intersection? ;; true if the patch is at the intersection of two roads5 E) o7 M/ H. N
green-light-up? ;; true if the green light is above the intersection. otherwise, false.3 u' `6 U% m7 D! H! @& k* D
;; false for a non-intersection patches.' G/ U- A+ Y* g3 ]5 z5 N+ q
my-row ;; the row of the intersection counting from the upper left corner of the
3 H) H; W9 b' v+ O% Q) ? ;; world. -1 for non-intersection patches.
* r- C2 h5 U1 R# Q# W my-column ;; the column of the intersection counting from the upper left corner of the; T6 {8 \4 p8 H5 R5 v# h
;; world. -1 for non-intersection patches.* K1 J) E7 k7 }
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
* k0 X$ @8 d9 h$ I6 S# C auto? ;; whether or not this intersection will switch automatically.
0 Y8 b* e( G$ u( Q ;; false for non-intersection patches.
( Y4 |- |+ h, |, s]
! X6 |3 `& g+ ?) J; h* G& `- s4 S* p
8 I6 z/ z- B3 v% c' y( y6 y5 W$ }$ b
;;;;;;;;;;;;;;;;;;;;;;( a; _$ |9 k, B W
;; Setup Procedures ;;
/ Z* }& K, ? X1 Q6 U/ Y! g0 z;;;;;;;;;;;;;;;;;;;;;;
9 ~0 p1 a) d( ?( ^8 B6 f$ j4 C2 i7 @4 }1 o0 E8 f: D
;; Initialize the display by giving the global and patch variables initial values.: [0 N5 c! P$ o: G; r- b) R
;; Create num-cars of turtles if there are enough road patches for one turtle to( h& J4 Z R9 v7 v( p/ Z
;; be created per road patch. Set up the plots.4 W3 R3 O$ Y# m5 j
to setup
4 k2 V! b7 k/ c, y0 e: @ ca
6 m: m( z- `7 y" v% Y: B" u setup-globals6 P5 l. u7 X" H, q# w
0 n! J" W; Z( o( K4 P$ }. v5 C/ K
;; First we ask the patches to draw themselves and set up a few variables" q; K% f+ @# F9 [8 E: @- L; W8 S
setup-patches$ P) \/ ^6 V6 L' F- ~
make-current one-of intersections
6 b" l7 M: W" ^& Q/ C label-current% E5 A! k/ |: `' j
?- J' @! w# N2 M, Y- {% o: p* \
set-default-shape turtles "car"
$ x" M$ X$ A! `) m6 O- D
+ c1 A& e. Y7 E' ]' Q) D" p if (num-cars > count roads)
4 x" ~! B2 C" M7 U$ _ [
; d5 N8 Q+ ]: a user-message (word "There are too many cars for the amount of "
2 P( G* K C: x- V3 T/ G% y3 d! q "road. Either increase the amount of roads ") R) _1 R) w" Q2 p
"by increasing the GRID-SIZE-X or "
1 k' B2 M* K. K4 F "GRID-SIZE-Y sliders, or decrease the "
0 N: N' ~% {0 ?- O9 c "number of cars by lowering the NUMBER slider.\n"
# O. I# }/ E% J1 b+ q "The setup has stopped.")# G( w1 L. p! ~
stop4 u1 q$ Q0 X3 u$ x1 V
]
( G5 m. Z$ e$ g+ ]2 J8 W* [
& a! h( ?7 [% |/ H0 j ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
6 B/ f0 l0 C" y5 f/ j2 \, @ crt num-cars: c* s& s b2 F0 n0 C+ S
[
" z9 {. y, O$ z- }8 K5 g7 G) k setup-cars4 b9 Z5 r2 D- u. ]
set-car-color7 O+ N( r4 g+ ~% h5 f1 x
record-data
0 t& |2 z. j: ~" p6 f ]6 _% [6 d/ Z( c5 `
4 O- b# L5 V, b9 q- C2 _% Y
;; give the turtles an initial speed
4 t S1 i A) V( { ask turtles [ set-car-speed ]
4 V! t. w& w8 L! I& {& d: u' M- e3 F: n6 m8 P, Q
reset-ticks3 M! O7 N9 R6 k
end
- a0 t0 e0 p( L7 p( d
1 n! N/ G7 P, l2 l2 L& y1 V' |;; Initialize the global variables to appropriate values) f$ o. Y5 n, E! n
to setup-globals3 @9 M+ W$ T! c
set current-light nobody ;; just for now, since there are no lights yet
* V! T& i8 S4 G/ ^- u set phase 0" \6 L' o# u/ x, n$ e5 Q6 H5 l- f
set num-cars-stopped 0
4 I+ a& ~ ^+ }( R! R$ J- v set grid-x-inc world-width / grid-size-x6 Q+ r1 i# H7 a! b
set grid-y-inc world-height / grid-size-y- d4 r0 }: }# S3 \; T- ]. K8 I
; I+ Q. f+ U" x T% a S ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary- ?! X' r) K& w4 x& M( e
set acceleration 0.099
0 G+ o3 f; F; l6 v$ Q' {8 y/ oend7 V( p, |( |$ a9 q
/ j; ]0 J5 T/ s' g# z/ ~: c
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
9 i, w8 m* C. r4 q# p;; and initialize the traffic lights to one setting
/ g5 k' f2 n! o1 s/ {; ^7 [to setup-patches/ O' T+ f7 J n/ ]
;; initialize the patch-owned variables and color the patches to a base-color5 ]9 o0 H7 D: I7 @$ V. h* N
ask patches
$ B+ r$ W/ J" Y% F. U, G; N [
/ H, @2 L7 I* {; y8 C4 a set intersection? false
0 m: j6 A; V% ~2 m5 p set auto? false# ]- H8 v( x, f9 l3 X& f7 J- d! h
set green-light-up? true' o2 K# h* P9 o" Z' l3 t& k
set my-row -10 `* E/ L q; _8 I- `+ A
set my-column -1& W% p( e# N, Y+ Z4 B# t# g$ Y# c
set my-phase -13 O5 x+ s* V5 x8 ?- X0 N& P g# U
set pcolor brown + 3
1 N* w4 G7 J; M. o# h0 a ]% @1 S; q# a5 i6 t8 p* y5 r
' M8 H- B- v9 D5 g, h ;; initialize the global variables that hold patch agentsets* V- @5 N* W0 r, v' z
set roads patches with
: t2 U0 ^) W3 V4 G& q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or, c9 c4 f0 E8 \! o3 D2 D% a
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
% H. \. `2 `6 _5 }) X5 d9 ~ set intersections roads with5 o7 p. Y5 u5 j
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
9 n/ S8 K1 r9 f6 g. ~& N2 E (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
+ V% k- P4 }6 R) U o) Q( c+ _" t5 h' X( e' y; u* C( d
ask roads [ set pcolor white ]
! j; n) t! I4 F setup-intersections
5 F! e* q& c8 Q. Z, s% @! qend
9 K9 V" J9 C" @+ U% K其中定义道路的句子,如下所示,是什么意思啊?
9 k' H2 G- E4 b. O2 {1 L set roads patches with
3 b- u" q& G! n5 h5 D8 |3 f' P5 } [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# O3 P7 N3 T: ~9 y$ }. e' H. \ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 V# w. w: x& y" n" m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? |
|