|
|
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。/ I& |; y+ U! b* }
netlogo自带的social science--traffic grid这一例子当中,
0 z4 @: R s7 |7 }6 P& r; @globals
- {6 ^0 W/ S7 @% s9 }4 L[4 j6 V4 X6 w- t8 d7 x
grid-x-inc ;; the amount of patches in between two roads in the x direction
# b. d3 y5 V$ g9 { x grid-y-inc ;; the amount of patches in between two roads in the y direction
4 d! b& ~- t4 l& h acceleration ;; the constant that controls how much a car speeds up or slows down by if
# z o: _; g& Q( w3 E0 { ;; it is to accelerate or decelerate+ |( Q- D) J Y% U8 {4 t
phase ;; keeps track of the phase) K" L d1 b8 N4 \+ C- o
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
; a/ F# n% Q. _: Z4 _! s" g current-light ;; the currently selected light+ E* v: {$ @ g# P
8 M; a$ G; Y% J( t1 S7 u6 z
;; patch agentsets6 _' u- t& Q8 g
intersections ;; agentset containing the patches that are intersections
" ]$ i( E3 |% l- c0 _! l roads ;; agentset containing the patches that are roads$ p& P/ K" E$ L& s, e. _6 ]+ F
]
" X$ K# p% Y2 L+ V# G) q/ L9 r! M- e1 L
turtles-own$ ]( M( S0 q! v( r" c
[3 i" V& V* L( k( q% {
speed ;; the speed of the turtle
* r% u, W$ l5 A+ [/ h4 M) Q up-car? ;; true if the turtle moves downwards and false if it moves to the right3 V: F9 {+ F7 r# |
wait-time ;; the amount of time since the last time a turtle has moved
, O4 T4 e r1 H- H. k: h0 |4 W; ]]
4 Y4 w$ @" }6 N$ }
* _3 n j- O& P, ?patches-own$ w' Y, {4 T1 k' l# O
[+ ^- |4 B: m' G
intersection? ;; true if the patch is at the intersection of two roads
6 I9 e& y1 U6 w3 K/ c6 U- G3 v green-light-up? ;; true if the green light is above the intersection. otherwise, false.
7 v5 W2 A6 B) k. B ;; false for a non-intersection patches.1 y1 h: G( I* N& q( l
my-row ;; the row of the intersection counting from the upper left corner of the t) M% u: r4 f9 o9 m, I
;; world. -1 for non-intersection patches./ g& Z& A* y1 f5 E& a; s
my-column ;; the column of the intersection counting from the upper left corner of the
8 D7 I# ~6 y. \# X! y ;; world. -1 for non-intersection patches.
2 E/ {+ o& s6 _" x+ w! [; ? my-phase ;; the phase for the intersection. -1 for non-intersection patches.
3 N. D# M5 }6 R# {0 r5 [ auto? ;; whether or not this intersection will switch automatically.
' \$ b* J2 q! _; @ ;; false for non-intersection patches.
' _1 A: P. L# ~% ^9 ?* j]
* Q$ O+ u8 |; v: |! w }* ?6 c1 s1 p' e: p7 D; h1 v; p
6 X7 _" ]- ~1 ], _
;;;;;;;;;;;;;;;;;;;;;;
" `" z+ P5 X1 ];; Setup Procedures ;;4 y1 g1 }# G9 I( E2 g
;;;;;;;;;;;;;;;;;;;;;;, |9 G* r# Z; ? M$ @8 ~
3 c& ~6 `( I$ W, B5 S1 Q/ M
;; Initialize the display by giving the global and patch variables initial values.
6 U* w' h+ }: I. ?* v;; Create num-cars of turtles if there are enough road patches for one turtle to# e, n+ t8 A0 i, A" h
;; be created per road patch. Set up the plots.
4 U/ ~0 B" m& L! ~$ `# o* Kto setup
$ N, q6 q, y" X* c w ca
5 }6 J8 I9 J' a# b+ Z q7 x6 Y setup-globals6 l; |- g3 T/ N7 s$ e9 Y+ U
6 E Z8 A) M( N7 A ;; First we ask the patches to draw themselves and set up a few variables6 n/ b' `! g# F9 O/ X6 ~- t. ` m; _
setup-patches% Q& @, q9 d& t% z n
make-current one-of intersections4 d' g+ |; v7 r- a6 A6 H; X- y
label-current
) f$ V1 }$ q/ [: z2 `
. f1 l' C* d6 X, R set-default-shape turtles "car"
# Z ?1 m/ h* a( `
& n/ B" N! m) f! {/ Y5 s if (num-cars > count roads)
6 N9 X+ z, F7 I* R T7 W [6 V! f+ {' R* G% U( j
user-message (word "There are too many cars for the amount of "
3 z6 [4 h5 i# }; j( [ "road. Either increase the amount of roads "
+ ~" g3 E4 H3 }$ x "by increasing the GRID-SIZE-X or "* O) W+ b, e: Q( \6 Y5 P3 K; m! K
"GRID-SIZE-Y sliders, or decrease the "
2 d6 A/ f$ S; k+ j* w, d1 d "number of cars by lowering the NUMBER slider.\n"
$ e) P& H% G9 k& r* a "The setup has stopped."), l0 s0 H- C( }8 u: q1 E9 o
stop
8 [0 b" f. z$ y/ z- Q( g( H1 ? ]9 E" N$ U b% l
: d# z( \7 h2 z1 u; w ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color0 q4 U0 a0 X p6 \( ?
crt num-cars
+ q0 l7 j4 G# `; D# C [0 G. h/ n* k0 m. R: Q) P
setup-cars
5 B+ C- b+ s2 t7 d0 Y5 G) A. M set-car-color
0 `. N( N, q! _ record-data4 c9 @: T- V( q8 F! d4 a+ Z
]
3 e: M1 f8 I, _% Y. [( S K- r( \. z2 i7 m! q% G) \3 K" B
;; give the turtles an initial speed9 j1 _! V. X7 F
ask turtles [ set-car-speed ]2 q: I9 ]& @! K" T9 j" P. V4 m" x
, \: Q' K1 z: \) B: |5 s) q8 B: l reset-ticks8 e( ]& \# C0 b! D: m6 e6 `) b3 p
end7 w7 b6 N3 g( N8 X9 ~9 j
Q+ M, @& N6 s- U;; Initialize the global variables to appropriate values2 b& @. E- _' M
to setup-globals/ S5 Z& l7 ?! A" O( @# Q
set current-light nobody ;; just for now, since there are no lights yet, U" I! `6 M! C1 c
set phase 0' D' _% U( E4 x
set num-cars-stopped 0/ P* L4 D( w% e! f* C
set grid-x-inc world-width / grid-size-x
; W1 a' n2 e; T; t3 {& j7 G" t set grid-y-inc world-height / grid-size-y8 U* b/ s( Z7 _( ^1 B
. d. `: r( F, J5 b( K1 }' ^ ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary$ ]" h* J8 X3 @
set acceleration 0.099. l) s$ @ I: \# p7 K/ v
end3 j$ t- ^" T: j$ L- l9 w1 g! Q4 R8 l
9 B7 W* {# u% U( U7 E5 X. x;; Make the patches have appropriate colors, set up the roads and intersections agentsets,: k* G6 x6 u8 w9 x
;; and initialize the traffic lights to one setting8 D- R7 Y& f, L& x+ G
to setup-patches
9 t0 c1 d" L5 u: I ;; initialize the patch-owned variables and color the patches to a base-color
) b$ B8 o1 O/ ?# Y! k* n2 K ask patches. r8 D; f9 t! y5 y8 I
[
" W" F3 y& d; p5 s set intersection? false
6 e3 k' O- o7 L1 r% W% j- l set auto? false
; o) ~7 C0 D6 V& e set green-light-up? true
/ _3 W+ Q+ ]0 B* j set my-row -1
4 Z; S: d! x) X* R set my-column -1
, D1 j% p2 ]0 P: B& ?, g) R" ~, Y2 F set my-phase -1
. R3 m: W2 o& N set pcolor brown + 38 h+ o8 X! v; ^ k P
]1 ^, ^0 H+ B$ `7 ]
! v" r/ u. |. d$ w
;; initialize the global variables that hold patch agentsets
4 U+ ~6 D2 U# z: n0 `' z" b set roads patches with
. W5 |) S1 X4 t$ p1 j0 | [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or9 a2 s l6 u2 u
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]* S8 P) n% B* x$ @$ s
set intersections roads with" g# X0 J2 I8 O5 O5 x! j( S1 C
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and5 w# T5 _. {/ F6 u& _( J
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
- k% ?- V2 p2 S+ P! G2 n- P0 o3 k2 @# d6 V9 |, ]/ o( [7 _
ask roads [ set pcolor white ]
" @- i( ^. Q; c4 A' j setup-intersections
1 ~/ H5 g- I" K }/ j2 `; ^end
& B" G4 x, c. _" `7 {其中定义道路的句子,如下所示,是什么意思啊?
/ A5 ]5 M/ v/ C set roads patches with
5 A2 [) ~; N: M) q; d% k2 ? [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) e+ O+ [) }& Y2 I. H* o
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 o3 P/ L- y! l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? |
|