|
|
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。
+ D3 m; L* W0 ?* Knetlogo自带的social science--traffic grid这一例子当中,8 m l5 d0 c5 w8 k7 U6 F
globals
" V! g6 {! g: Q. ]+ k! _[3 k( C' Y9 r3 y2 H* J5 j
grid-x-inc ;; the amount of patches in between two roads in the x direction4 L& o3 x' s! ]
grid-y-inc ;; the amount of patches in between two roads in the y direction
( a2 |3 v. ?: E, m. U$ M acceleration ;; the constant that controls how much a car speeds up or slows down by if
+ q5 w+ q3 i. j" {' A. Y4 A ;; it is to accelerate or decelerate; E& l9 d, j$ P7 y6 I, y5 O; H8 d
phase ;; keeps track of the phase
$ G: }6 M3 Q4 L3 j num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
/ u2 S' a. X+ L2 C" S& z current-light ;; the currently selected light
3 N5 Y0 K6 K" f/ u# i7 w
) _! }$ q4 X3 M: Z% K7 I! x ^6 L* I ;; patch agentsets: [1 y3 |4 k" s* `; R: @
intersections ;; agentset containing the patches that are intersections
3 Z' G" X) E' m0 V# m" H roads ;; agentset containing the patches that are roads
8 [ v+ b8 S' \; |( |: V]3 K9 a. _: o; M3 Z" S* Q: i$ T
9 D0 o. M) e, U/ z1 Q. P
turtles-own
) M2 H, c/ \4 P- P[
& {1 d! u, t: }- @( D speed ;; the speed of the turtle2 B9 V k3 |5 e4 x' |
up-car? ;; true if the turtle moves downwards and false if it moves to the right( N7 j$ W4 ?& P0 N8 L% R v
wait-time ;; the amount of time since the last time a turtle has moved* N& Z( L( n& u+ _" R. d
]
' n1 W, z R. y4 M( @% a: n# Y _7 i8 q2 j! `7 h2 e
patches-own
& c- |% y% Z m5 J[
+ | X+ U0 x/ t3 b, h intersection? ;; true if the patch is at the intersection of two roads
1 n6 a) T# ]7 a7 [1 }) O green-light-up? ;; true if the green light is above the intersection. otherwise, false.
& c2 c, W! Y! ~' Q2 y9 M ;; false for a non-intersection patches.3 C' M& j8 ]# h
my-row ;; the row of the intersection counting from the upper left corner of the! B! f: `" ~5 |7 M
;; world. -1 for non-intersection patches.
' E5 F3 u# a c6 V" F5 k my-column ;; the column of the intersection counting from the upper left corner of the
5 M$ c, m7 M5 W4 c2 ~2 y8 r ;; world. -1 for non-intersection patches.# @" W& l3 G# ~* E
my-phase ;; the phase for the intersection. -1 for non-intersection patches.# i K, C2 |- @/ v
auto? ;; whether or not this intersection will switch automatically.
) `# s. c! ?( s* q; m" r2 R/ O- M ;; false for non-intersection patches.
5 o6 e1 D. k5 P1 j% K u9 M]# ^& `6 B* T% O! Q
' [* E" t1 x0 Y$ L
9 C a x6 C5 m# _+ J( a, q;;;;;;;;;;;;;;;;;;;;;;) f$ Q2 B' j& |, Q3 O0 s& [
;; Setup Procedures ;; {3 q* Y& S" q1 i0 l
;;;;;;;;;;;;;;;;;;;;;;4 c4 I4 |5 X6 G+ R6 o7 W( h) ^1 @& [
# t6 B+ N8 J5 z6 j;; Initialize the display by giving the global and patch variables initial values.
' L; c$ ]4 m1 V! y;; Create num-cars of turtles if there are enough road patches for one turtle to
! ?2 b* Z* k y; Y( d3 D;; be created per road patch. Set up the plots.
6 r. C% [, w) r& L- e/ Yto setup
- K+ F1 x/ G( w0 A8 d ca2 k9 i E" A/ d( J; `
setup-globals5 U Q4 {, m9 R. B8 j
0 T" I8 K8 |! u" ^" f ;; First we ask the patches to draw themselves and set up a few variables
8 S N% P! @; S" p {7 M( O setup-patches
$ z9 L: @5 z+ g make-current one-of intersections
_( X% ?4 q7 E1 Y. D! d* X- Q5 h7 } label-current
7 J' y' h! l7 m. V9 v( P% x+ |4 y% j9 e9 w* |7 I0 e* \
set-default-shape turtles "car"
$ r8 M0 o0 g, w* Y5 p7 Q3 H
0 P- m5 C7 [+ _4 ]- a if (num-cars > count roads)/ }, c0 ^: W9 M! i1 r( O
[: w7 G; |" X6 Q5 X
user-message (word "There are too many cars for the amount of "
8 C( Z! H+ T9 V g% O6 k* E- \( j "road. Either increase the amount of roads "
& ]6 Q& D# o0 U: h "by increasing the GRID-SIZE-X or "; F, f2 W8 Z; _/ H
"GRID-SIZE-Y sliders, or decrease the "
" |! K+ o4 i% V "number of cars by lowering the NUMBER slider.\n"( G/ X& x8 O" [- { G m
"The setup has stopped.")4 e9 h9 F' P7 X$ L
stop
2 `; e3 v" C$ I7 o) V9 P3 A9 V9 `9 d& _ ]" ?& R' K f2 G: W6 w3 p
% Z2 v1 _, S( O ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color5 X3 p5 C6 F1 o ]- j
crt num-cars
( u& w3 I. o6 ^/ F' O4 f [* a- N3 ~3 O! r$ J0 E& D
setup-cars
2 J6 `6 R0 C; u9 ?; |% q set-car-color) J, G6 l- C8 @( X
record-data, r" W2 y( K4 b
]
, i& l1 M9 _3 I. t- s7 K# c- W7 D: `
;; give the turtles an initial speed7 t4 n! O& }6 W8 R
ask turtles [ set-car-speed ]
. L+ b2 K/ {5 x/ S
) l& m" ]3 R6 L4 T& B6 ~, V reset-ticks
9 {" z# d3 s# p% u, Xend
8 K; ]- a. ?; \3 t5 ?& b' @1 A
' l7 L5 c2 M4 g& _;; Initialize the global variables to appropriate values
, [) q1 X3 c. ^) N0 |6 q( ]2 [$ gto setup-globals
7 W: S9 Z4 J0 Y' b4 ]: N: l set current-light nobody ;; just for now, since there are no lights yet
7 L* r4 M4 K2 h' g8 O2 g$ W* n set phase 0
, V P0 F+ [& k/ d set num-cars-stopped 0
4 `/ e" O* _2 S0 c1 E set grid-x-inc world-width / grid-size-x
5 ]6 i3 X, k7 p0 b% K set grid-y-inc world-height / grid-size-y
& N9 j5 ]% y& g% j5 k5 k+ s. @ A! H/ |* c6 ^
;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
$ g8 F- `; ]$ Z2 n- @8 \; z set acceleration 0.099
# M A5 N+ F4 k+ Nend3 f+ k" B. {4 S( p9 W
8 V1 u' r, H! c% ]* d# o9 ]3 z+ w;; Make the patches have appropriate colors, set up the roads and intersections agentsets,$ T# `" }1 u8 k+ M
;; and initialize the traffic lights to one setting- G: S' W, E. s
to setup-patches# T* t2 ]/ q z! Y$ a& H1 ^
;; initialize the patch-owned variables and color the patches to a base-color- y% N5 A- Q9 t' v( Z. f: j% {$ K
ask patches, Z x0 T Z& X s
[! M! Q3 _& M" W/ x+ u# N1 E! c* y
set intersection? false
! t. P0 C. J& Q, M! R set auto? false) _" k6 ]5 D$ ?7 m1 M
set green-light-up? true
- |! H9 R: [ U4 Q h6 M set my-row -1
* T0 N' i8 b+ u. b9 k8 R4 W9 U set my-column -1; Z7 W3 |0 n& [0 A7 [7 c
set my-phase -1
8 ?5 h. l3 A0 [ set pcolor brown + 3
" d, M. J+ h: _" ~' o5 x ]
! P% I6 T% s w
- U$ }0 @ o* j4 q: q. i4 C( z ;; initialize the global variables that hold patch agentsets6 ]( |2 n3 `1 W/ @: N3 u2 ^3 o8 r8 O
set roads patches with4 p4 u* ]$ `/ p) D8 G' T7 o
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or( \/ |% g0 c) O) F7 s- b( c2 E( h
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 U0 N6 F9 q' `. h! T set intersections roads with- M, C) X" F2 T" ?4 B" U( z
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and* R6 Q+ N% F1 L
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
% q8 ?* v w. c' z5 [# T4 b+ P! V9 @( ?
ask roads [ set pcolor white ]' P, e) z$ u2 }- Z& X: @
setup-intersections# m7 X1 t8 j. A$ Y
end
8 O1 Q2 h2 h9 c7 K6 @其中定义道路的句子,如下所示,是什么意思啊?
+ r; O: @$ i/ u$ p( M' S set roads patches with
& u" k- o6 ?5 W+ I m [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or5 `0 g, t8 l8 {: ?" o# ?
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 P; f! W' ~4 a. H% F2 I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? |
|