|
|
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。( ~4 `9 z6 C& c' K
netlogo自带的social science--traffic grid这一例子当中,7 Y- W* j% `" Y" A+ o& B8 b( w
globals
# G! p. I6 F: z/ g7 d# U[- \+ L' F* M \) m" y
grid-x-inc ;; the amount of patches in between two roads in the x direction
& p3 R& i- A- l, Z4 M$ k grid-y-inc ;; the amount of patches in between two roads in the y direction3 _+ Z7 T, E& m1 J/ ?# w
acceleration ;; the constant that controls how much a car speeds up or slows down by if
6 E4 V) b/ B$ K: @7 D8 }+ a8 K ;; it is to accelerate or decelerate4 a0 ]6 v0 T0 O8 R `, @0 \, n8 U
phase ;; keeps track of the phase
. o f5 z8 Z# A! {+ l' A4 B num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
0 W. S: P' m/ J5 l current-light ;; the currently selected light# _% C. q/ U& f% {" j2 J
9 w2 t; T, k. d c/ m+ y+ Y" H
;; patch agentsets$ s( H0 `! b& D: z; t5 z
intersections ;; agentset containing the patches that are intersections. l9 k) u/ a" m: j
roads ;; agentset containing the patches that are roads
% F8 X1 g0 U0 i; O! F]
& n" {* y% m9 Y3 @& \5 T8 M2 M; T+ s H% }7 o' U
turtles-own- d1 A7 _* I4 d1 b
[
& p% Z3 U' I8 o- `- I speed ;; the speed of the turtle; ~7 C5 Z. D4 n+ l+ Y' P0 {& t! U
up-car? ;; true if the turtle moves downwards and false if it moves to the right
% ~/ Q* @& K- ^- j5 u5 q' x* k& D wait-time ;; the amount of time since the last time a turtle has moved
. b% }: v' O$ K! _! B9 S]" p' a! }0 B# x: \4 p( Q# W
/ o# e* I$ K" d
patches-own5 G) H9 e% B' Q/ n% W/ d4 b8 \
[
; l4 u0 d+ H( S9 D/ j7 N) f intersection? ;; true if the patch is at the intersection of two roads+ d$ o3 A* }% F6 o( W
green-light-up? ;; true if the green light is above the intersection. otherwise, false.* m: P: _7 F" s6 g/ b- Q
;; false for a non-intersection patches.
3 S4 ?! Y i0 Q my-row ;; the row of the intersection counting from the upper left corner of the
; g: t% g$ d" Z6 J( R ;; world. -1 for non-intersection patches.1 S L8 v- i2 a8 Y
my-column ;; the column of the intersection counting from the upper left corner of the
9 l7 S% P$ c9 ^# P L, h ;; world. -1 for non-intersection patches.
) t* M+ D$ I) C) O% [8 f7 X my-phase ;; the phase for the intersection. -1 for non-intersection patches.; H8 F0 Y; |7 ^, k0 \ _
auto? ;; whether or not this intersection will switch automatically.
& R. T& v, w M' B: y& S3 K/ k ;; false for non-intersection patches.
0 L) t" f1 L. T' i8 c]4 w9 i+ _! V# F& N
, S A8 T* T0 Q( n
) @# u" H8 T! Y. F, y
;;;;;;;;;;;;;;;;;;;;;;" J a7 X8 u/ _% i& R/ S: _
;; Setup Procedures ;;% p+ v$ v& T9 l5 z
;;;;;;;;;;;;;;;;;;;;;;$ n2 A# i( a+ F6 C8 A
9 U) @& E" l0 B* A$ O# S
;; Initialize the display by giving the global and patch variables initial values." b/ a, D; A4 Y. P6 l' L) @
;; Create num-cars of turtles if there are enough road patches for one turtle to
" g6 P' k% W3 {, Y W5 f;; be created per road patch. Set up the plots.
; d! a/ c m% {4 G+ p/ rto setup
" Y" j, Y- Z. J0 u) q ca
9 T$ A# F6 @$ v setup-globals
" E, h1 F: H6 k2 P
4 m" T9 o- x. T9 L! u ;; First we ask the patches to draw themselves and set up a few variables; c- V5 u- v6 j6 d' v
setup-patches
6 S3 M* n- n* _5 M/ { ^7 L2 s* d make-current one-of intersections
- M/ J/ p+ X) m+ `" X; | label-current
$ `' Y$ k- @% b% f. L
0 s1 b6 i) r) I; y set-default-shape turtles "car"
/ b1 G4 B: z) u/ O) h; ^
) v. E% k) |" R if (num-cars > count roads)
7 a+ _- }; J E4 z* \7 v2 ? [
# f0 P* w1 l* I5 e. p2 ] user-message (word "There are too many cars for the amount of "
; K5 f5 o+ D- h- D; c "road. Either increase the amount of roads ". z9 s# A, b1 G
"by increasing the GRID-SIZE-X or "
, I- h+ w2 `( D x "GRID-SIZE-Y sliders, or decrease the "" d2 B0 ~5 O' E c" p8 |% Y1 o
"number of cars by lowering the NUMBER slider.\n"
* a$ e& Z2 _/ M4 Z "The setup has stopped.")
! y$ G( v* H8 K) \. o8 O stop$ A' _, M3 v% F/ \$ q1 j
]+ { k. C+ ^4 H- i* h
% z. E9 i/ |% n0 }5 x
;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color* V) P2 ]% S2 |" G4 g+ W
crt num-cars4 L2 M! R- N1 Z% N
[, X" g% @9 n$ }! l& x
setup-cars3 q/ a; z/ q2 Z8 ?% _
set-car-color' j' [( R( _' K ]6 ]) f
record-data' ~' b2 R9 U) x! a* ]' X2 y
]5 b2 ]3 _: f6 m
3 N8 c& r8 \/ S, i% y! a( ]
;; give the turtles an initial speed; K) G X* c( T1 Q
ask turtles [ set-car-speed ]
& s+ H% ^/ Z/ }) x: c9 z& G F9 l$ P5 B: A0 z, Z1 ^/ t% H. w
reset-ticks
0 K3 _7 H/ o4 Z( Z dend: v0 Q: n! t- c8 n# Y1 ]
& N7 c1 D# s( `! C9 H2 Q;; Initialize the global variables to appropriate values
@ m/ _: W( X+ J* k8 B/ wto setup-globals
8 |5 H/ {' T. h" D0 P4 l9 G/ F set current-light nobody ;; just for now, since there are no lights yet
+ _0 c+ H Y- L! f set phase 0
6 P5 |& |/ v) [; T9 T+ U set num-cars-stopped 0
" [ x/ h+ g, J7 H9 a. b set grid-x-inc world-width / grid-size-x
/ p- S* a. N" h' R3 y0 Y set grid-y-inc world-height / grid-size-y
! v! R1 n5 _6 ~" K3 ~" N- R! H! T4 s' V9 L
;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary }8 O( f% E1 S, Z/ M8 j
set acceleration 0.099
1 }9 z% g" T& y9 Z# u+ Send
/ i/ R( C- {, h. y9 J1 Z5 r! y. J9 L$ `& `+ ]% K3 ]2 A! t4 Y
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
; Z- j8 l, D" a* b6 ~* u;; and initialize the traffic lights to one setting( w/ Y$ I& y' U& a, H5 @! @0 W6 O4 M
to setup-patches
V' L4 B G m( x6 ]& p2 d ;; initialize the patch-owned variables and color the patches to a base-color3 T) A! C9 o0 E! n! c2 d
ask patches
. E' l, `' M. ^+ `' a$ Q! Z [9 |! U7 l, B* \" c* B1 g; |; v1 {5 C
set intersection? false3 o# X% ]) ~1 G. P: }7 k
set auto? false
A3 C9 \ l- } set green-light-up? true# V1 t3 o. z) h6 K
set my-row -1
+ }# C7 e$ C% C0 U7 o+ s/ r* U* | set my-column -1
" q: B: W' m7 l8 Y/ X% | set my-phase -1
9 ~2 Y i3 b. a7 e" A set pcolor brown + 3: e7 W* x% E) K2 A" u7 B
]
3 y8 s$ v- ?% P% b; ]- }( P0 [. j( |
;; initialize the global variables that hold patch agentsets, H S# v& w( h8 G% M- z
set roads patches with
' u! ?8 v. w% [+ @5 W! j7 v [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 f! |' ~1 B" S9 H7 B (floor((pycor + max-pycor) mod grid-y-inc) = 0)], Q$ X& g. i; G
set intersections roads with
" F8 J! c+ [6 l0 v [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and9 }4 X' H9 U) N ?5 @* c( ^
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. E( V# f! j9 @# d: {9 ^$ d0 B8 F0 H+ @$ F8 N: W
ask roads [ set pcolor white ]& j( i3 w9 R2 a3 n' ]
setup-intersections
1 s1 s5 K9 h( M3 @9 S( `, n/ ` Iend
, d9 y1 Q' [3 J其中定义道路的句子,如下所示,是什么意思啊?8 y9 w- V3 C* X% _* a! t
set roads patches with: i q9 ?" I2 Z" p+ e1 p
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
u. X# U5 u, B9 E; b* A! ] (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
' q: |) M3 C3 W) }% K1 b2 P# p0 G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? |
|