|
|
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。( B& R; ~3 b" S! N2 f
netlogo自带的social science--traffic grid这一例子当中,
. y' u: N% z! E. U: i9 }1 i T& kglobals
. C2 q: i9 \ [! q9 `[1 p+ ~0 B1 @6 m
grid-x-inc ;; the amount of patches in between two roads in the x direction8 b9 Z! ]2 V6 Q
grid-y-inc ;; the amount of patches in between two roads in the y direction5 {& }. n* l6 g4 g
acceleration ;; the constant that controls how much a car speeds up or slows down by if
1 J' g, J8 C I: } ;; it is to accelerate or decelerate
" ~6 e( c3 d6 x5 F0 \ phase ;; keeps track of the phase) b9 `. L0 y% B' o1 o( r6 v1 @; M5 T
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
3 T: V4 Z$ N S current-light ;; the currently selected light3 w0 z( K. }% Y& i/ m
- f2 y% J5 y& h" K, R7 U ;; patch agentsets( B4 K0 l6 J2 W- s) l4 D
intersections ;; agentset containing the patches that are intersections* l' ?8 U) w1 p, X
roads ;; agentset containing the patches that are roads
+ ]1 l5 S- V* ]2 b) j7 Z: {]
+ i; P+ t S5 U8 W/ I* _4 F0 U6 c" i" x/ V
turtles-own" r: H" c8 b2 p2 {& Q& |0 F: I
[; X( V7 c) u ~3 {8 y+ x3 a
speed ;; the speed of the turtle Z) z0 K4 @1 D" o
up-car? ;; true if the turtle moves downwards and false if it moves to the right
* c+ J- ~1 m+ v5 W4 I/ G wait-time ;; the amount of time since the last time a turtle has moved" k+ _/ l; W, @" A5 d6 f# I
]& |' {! ?1 ^% `0 [3 L+ {0 Z
3 e5 N+ w. j1 C' g! f& `* K2 p5 |
patches-own
' @( K) a) u+ A# h: Q% Q+ K/ Q[
% _4 V. ?% ]. \ }& Q' [( [/ ` intersection? ;; true if the patch is at the intersection of two roads G; }$ e( x. g! S w
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
* y+ u7 G' R, Y! N. ` ;; false for a non-intersection patches.
4 C8 ]* W$ D4 _ my-row ;; the row of the intersection counting from the upper left corner of the
4 l2 B* E5 K1 Y' r+ Q$ [. ` ;; world. -1 for non-intersection patches.
4 Z) Q: }7 `: u4 P* L& Y8 v my-column ;; the column of the intersection counting from the upper left corner of the
1 G- [+ ]+ B- R- P ;; world. -1 for non-intersection patches.
! f- M$ G4 }$ k R# X my-phase ;; the phase for the intersection. -1 for non-intersection patches.3 O! Y- L7 D2 {7 t
auto? ;; whether or not this intersection will switch automatically.
# ~: x) `5 w) V" o; G8 ?; c2 M ;; false for non-intersection patches.
9 P% [- A M6 J2 H% O]& D2 I8 k/ l6 _ e
1 b; X! T+ }( V u) h
& E& ~# A, G4 T2 ]$ e; R
;;;;;;;;;;;;;;;;;;;;;;
* e+ q! [4 j" y' J0 ? q7 M( ];; Setup Procedures ;; o; Y, U5 O- e
;;;;;;;;;;;;;;;;;;;;;;
0 v! X8 A: E6 \* Q& m; J% g6 T3 Z9 r1 H8 F2 Z/ G9 y" _
;; Initialize the display by giving the global and patch variables initial values.1 b( W/ M% r# M+ P: T. x
;; Create num-cars of turtles if there are enough road patches for one turtle to; W3 F3 ^% Z$ M
;; be created per road patch. Set up the plots.8 `* C3 l4 `8 C6 s5 ]
to setup
; w( e* J/ H. r( y! y* y" { J ca
5 R7 H$ e: Y8 }/ b+ c setup-globals
" }1 R5 I" d9 p' R, t9 ]
# T9 \ @# R# H X ;; First we ask the patches to draw themselves and set up a few variables
/ A# t; v# F0 s( x4 z) G% x setup-patches
; x$ k8 l+ c! `( ] make-current one-of intersections* ]; [$ S$ t0 v+ b0 u
label-current
7 h: D x0 e1 f9 G3 W. N4 y0 Y' b. |: n" r7 @& d+ m
set-default-shape turtles "car"' v7 j. @& f1 j) P$ [% l; o
& j9 p* {4 E8 m4 k" ]/ S- r% B if (num-cars > count roads): U9 J2 w. ? D$ Y
[! c$ v4 S' V |7 H+ _
user-message (word "There are too many cars for the amount of "
# M& x" M- ]' A1 K- S; ` "road. Either increase the amount of roads "
& ~* y! R0 I9 m5 a "by increasing the GRID-SIZE-X or "* T2 h# x7 G2 V7 C+ ~
"GRID-SIZE-Y sliders, or decrease the "
' Z9 B& \. B" [# ] "number of cars by lowering the NUMBER slider.\n"/ A" ^" _4 Q( h2 F
"The setup has stopped.")& ?8 t; x) \9 l4 ~) i1 {
stop1 s S# m) D" B4 G& X. J& r
]. m% [# R- q! i4 @1 L
/ ~+ d0 z# M i ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
0 @3 B, E3 k& S1 y; |4 j crt num-cars
3 d* g" O) L7 R+ L% J [
: a- [; z( H9 v1 ]3 z3 w setup-cars
9 D( b) g+ t( w P% H set-car-color
) [, a; W, J. w Y/ ~1 W9 m9 |8 j record-data
7 o% y, v5 _) w" ?: i ]2 |2 [2 \; x% i0 A$ n a
M% g2 m; r+ k: e+ Q9 z ;; give the turtles an initial speed
4 a2 ]0 Q( |6 |; B5 k$ s ask turtles [ set-car-speed ]0 K8 I/ Q( ^% K) c
3 L+ c6 o3 s4 W2 V+ e reset-ticks
+ y1 ~ V) P% {5 xend, `. y I: i$ c6 \7 u: h
1 A% @* t( N: q' B. w
;; Initialize the global variables to appropriate values
! P' l9 f& v+ U( v" g( D& Vto setup-globals
+ X$ E( F: N* @ h* `0 a5 M set current-light nobody ;; just for now, since there are no lights yet1 d" S+ d- q4 y1 D, ] k8 P2 B: z+ Q' s
set phase 0: `/ ]9 k K/ b* f; y6 u& R- U X
set num-cars-stopped 0! m' v: y) P0 X# G5 e
set grid-x-inc world-width / grid-size-x! k. f) j# a" ?5 V u% F* [/ h
set grid-y-inc world-height / grid-size-y
, N4 G3 X6 F: p9 R5 Z; H4 x3 N
& e+ j7 g$ M) h' X6 n: ]5 `$ u ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
; z4 V! C& ~# F1 B, A set acceleration 0.099
( z ^- i' v2 j' l* {( Send
/ j! f1 S6 W& y+ p2 \4 b
4 P; j# U( u6 v;; Make the patches have appropriate colors, set up the roads and intersections agentsets,' R# b" c; {5 i. t0 w8 H! t
;; and initialize the traffic lights to one setting% d9 s9 E# k/ c, w
to setup-patches
% \" i; ]$ |, [ z8 ]1 o ;; initialize the patch-owned variables and color the patches to a base-color
4 n+ P" y0 B! R ask patches
( O5 t' _- [! V6 T& l* L, n% V [6 v( [, s7 ]* E2 C8 n5 T
set intersection? false
1 H" @) ?8 \6 k6 ], ~8 d2 _ set auto? false8 E$ l4 u5 [( i( H- W4 | i u
set green-light-up? true+ |+ S8 B X* U' T. T- g# b# j
set my-row -1
G- A+ L( W, Y set my-column -1
2 }1 B$ O- G9 b& I set my-phase -1
1 |! f, f4 Q* j n" q set pcolor brown + 34 U7 q8 h. o/ E: a$ e7 k
]
6 k; i+ n: A$ X" T. g4 E/ Y/ s9 v* F& f
;; initialize the global variables that hold patch agentsets
$ D, H9 t7 p1 N' K set roads patches with% S* M* N6 @5 m% H; n
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or1 p$ [' l8 Y4 o8 |0 y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* w; q ^' @& O+ G set intersections roads with/ P3 F- C; U! z6 O
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
" \3 T: S& h- L$ ]2 o (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
- W; f' A( o; @+ J- Z. c1 Q- H2 k) q( t7 d
ask roads [ set pcolor white ]4 @8 C9 g; q" T2 Q$ z' X' |
setup-intersections* d- V8 G$ w, P/ Q/ [
end: b* S) R/ b6 _$ v: l
其中定义道路的句子,如下所示,是什么意思啊?
$ b4 r1 m l+ T set roads patches with
. _! W& `5 x* ~ ^8 ` [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or4 d; L0 ]& z X& q4 W+ O9 }
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
7 |8 ]6 H L3 r# T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? |
|