|
|
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。* K, b, \# M2 s, ^' h- @" P
netlogo自带的social science--traffic grid这一例子当中,
A T# w4 V1 t* Cglobals1 i V% q! V! b, c; q
[
+ k1 f4 u" u5 [ e grid-x-inc ;; the amount of patches in between two roads in the x direction
* @9 \+ o) T: t% c. i; C! g+ J+ w grid-y-inc ;; the amount of patches in between two roads in the y direction7 k. _2 V ]* {- D
acceleration ;; the constant that controls how much a car speeds up or slows down by if
7 U6 F4 w7 }' V# h8 x& X ;; it is to accelerate or decelerate
8 H$ d# X6 ]! H5 h$ K phase ;; keeps track of the phase* E" V2 |* W$ u+ [: V; d
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure: ]* ]% D5 A( h4 k, {. q1 p
current-light ;; the currently selected light5 b0 _$ U/ A* D$ D6 O. d) _
y- I0 B4 F6 S2 n ;; patch agentsets
. N- n% t X- Q* J$ M' E intersections ;; agentset containing the patches that are intersections
, u" L- {" `3 q! Q8 G roads ;; agentset containing the patches that are roads' g4 W9 a S3 m: m8 K* ~
]- V4 X' i4 M. G( n( V& s- X. ^
, [" ?- h. Z$ ~0 j+ |& j$ X$ s
turtles-own; |$ P7 L7 ^- r
[
7 u7 J- K: J; S( x% P; M speed ;; the speed of the turtle
& w V, S7 `4 a6 }6 J% H( j up-car? ;; true if the turtle moves downwards and false if it moves to the right5 e& P- d4 K6 i7 }
wait-time ;; the amount of time since the last time a turtle has moved
. ?0 J2 r! C* k8 i1 _]4 z1 \4 n- y% w3 F- @3 [3 h
M( Z; y. J7 A
patches-own7 [( x% x2 \- b; Q& H0 J- [
[
& ?" p" T; E% s/ P5 M intersection? ;; true if the patch is at the intersection of two roads6 M4 M) m$ Q0 B& S( v8 f& H
green-light-up? ;; true if the green light is above the intersection. otherwise, false.5 r3 c. [3 Q; \5 {1 O, c8 N
;; false for a non-intersection patches.1 | m5 V/ b( f$ t
my-row ;; the row of the intersection counting from the upper left corner of the
! U3 ?3 n4 _ q5 @5 z6 I# Z ;; world. -1 for non-intersection patches.
; ]) }! A' j0 s my-column ;; the column of the intersection counting from the upper left corner of the
) B! x4 c5 F+ [8 A: a' w1 r ;; world. -1 for non-intersection patches.
5 |* _# o0 d8 n' O% F7 ^ my-phase ;; the phase for the intersection. -1 for non-intersection patches.! D6 M8 Y$ _: m# ~
auto? ;; whether or not this intersection will switch automatically.
+ b. o& C* V9 r- c0 n: P ;; false for non-intersection patches.
1 o# p) D0 ^+ t]6 o ~5 W9 z" x2 x* ?5 T
/ Q3 O) g9 U& W% C8 a, f' L
: ~$ W- [* d. ]5 D;;;;;;;;;;;;;;;;;;;;;;% }$ o0 x" E* x9 H- z" Y; c
;; Setup Procedures ;;1 g6 D+ v7 }2 x& ^( @
;;;;;;;;;;;;;;;;;;;;;;
4 @& D& ~/ b) F/ C3 q, D
6 n/ b6 {% ?; ?;; Initialize the display by giving the global and patch variables initial values.9 L7 x$ _# u/ n' s& W
;; Create num-cars of turtles if there are enough road patches for one turtle to
9 \% L2 n7 K# T4 u o6 a7 i$ i;; be created per road patch. Set up the plots.0 h9 z+ H, w# s/ f/ |" S
to setup' D9 e2 ? x7 |) f: f+ b+ ]
ca) {! e7 g5 r2 j% l, Y g
setup-globals- u9 F) W7 Q/ G3 G2 m6 z, [
5 z) o# O5 L+ Q% s0 M ;; First we ask the patches to draw themselves and set up a few variables3 e% @3 Q. ?( d* A) d( m/ ^, E) }2 A! x
setup-patches+ H; _/ h+ p* v& B v
make-current one-of intersections' e$ G. g4 d3 h* d
label-current
$ R( C' [" t$ \6 }/ r* D: H6 @
$ x3 T! |4 U" {& I6 M set-default-shape turtles "car". S1 E! {3 J5 M; q8 [% w2 E
1 X) X: [6 s' M3 x
if (num-cars > count roads)
( m* A/ V1 l4 w, [' k7 {& ^ [
) }$ T0 R) H2 f Q! y% |. F user-message (word "There are too many cars for the amount of "! ?. ~$ P3 f/ P9 P% u! {
"road. Either increase the amount of roads "
& r5 S7 S7 F. G "by increasing the GRID-SIZE-X or "
. C- ]' x1 B+ x9 s "GRID-SIZE-Y sliders, or decrease the "' o- [" r5 s' x# _1 s) m. c
"number of cars by lowering the NUMBER slider.\n"- d2 E% T3 O9 ]+ d6 e" M
"The setup has stopped.")
; [1 a& e1 X! a4 o2 a stop
! }( j5 O- K+ W8 [ P2 ? ]
0 V1 D; T8 ^, Q
7 d; j8 K# n* W% w! E ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color* ^! t+ D0 G, \5 Z" M+ Y$ Y
crt num-cars4 S; i0 j+ s7 u0 y* f3 B, Z
[
; f( E) M' M; J( P setup-cars
) E' F7 `+ t; ?/ _: X set-car-color( i, _# U1 [7 {9 w; l5 p
record-data. y3 U0 _$ O* J4 T
]5 O% Q" k( I2 C5 J! ^" Y# J
. Q" n5 m. L* J# t2 h5 C
;; give the turtles an initial speed
9 w8 G& @2 E+ u3 Q! H2 X ask turtles [ set-car-speed ]
% I, F4 ~0 Q6 s+ _0 Q
, ]; ^) e: B' b5 q% g" | reset-ticks6 C7 X( R# c& t
end% B8 U) D2 f' F+ ?
9 R4 ~0 S( v7 t9 m3 V;; Initialize the global variables to appropriate values, y2 S$ F" ^7 U; A
to setup-globals
! H6 Y3 |; g7 M3 X+ D* _$ D7 K set current-light nobody ;; just for now, since there are no lights yet+ q- F- f& O! p7 w2 g2 C) E& e
set phase 06 I% x$ v6 q1 {4 d# ?
set num-cars-stopped 0+ P- u! @" y. m8 w8 W+ f; V C
set grid-x-inc world-width / grid-size-x: G3 |& T7 I# T& I' K6 u; @
set grid-y-inc world-height / grid-size-y( W4 e- {0 v8 F Q6 k
& d, ?" h: D* J4 D8 b0 @( I2 X1 y ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary5 U Z9 o$ b6 I/ [, f! [
set acceleration 0.0990 L4 |, V8 B9 ]+ J9 `, ^( E
end7 V9 `3 w3 b. r! e7 q+ n# N( u6 n
$ v2 A0 |- D5 A; I' v
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
/ _, c0 f1 A' a( b;; and initialize the traffic lights to one setting( w( ~( Q: j) `2 p8 o
to setup-patches
+ E2 Q! |* N" f$ |, P ;; initialize the patch-owned variables and color the patches to a base-color/ P( b% e X9 ?, I( q+ c% f5 M; _9 _
ask patches" H }/ F. {% q, J7 @
[$ O' K( @+ n- n! s r. M* v. y5 P
set intersection? false! l0 I% W4 G$ E$ V8 ?+ o/ D
set auto? false6 i V- i* @" F" n( T: @* V
set green-light-up? true0 N4 Q% ~: [! @" W+ s6 @% A, G
set my-row -1
: r: E2 _( t9 G2 {$ a set my-column -14 [" J- W0 s9 K- B+ e# d! f# }
set my-phase -19 g% j- B0 s: h" R0 u1 o
set pcolor brown + 38 v2 c0 E+ \) ?( G; ^& K( E: R
]
7 f5 E9 C( E$ u8 H& N& H
3 ]# d" l5 i3 ?7 D ;; initialize the global variables that hold patch agentsets) J5 W' {! C/ K9 ?, A
set roads patches with
: ]! G& W D9 U$ E' S3 j [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or0 u. n* E! Q* K! z, w# h
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 Y9 \3 ?8 N; K9 x set intersections roads with
" K! V* Y9 ^, a7 C [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and: l4 ^' P* R6 W2 d: ~8 o1 R
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 z6 D/ T3 R0 ?6 a
5 \8 e4 p; c1 ? h6 {7 b. A% W ask roads [ set pcolor white ]
' g6 Y* n# K7 {2 w; V9 f setup-intersections
0 d6 m' h' x. x& Pend9 R$ q0 M. L. W- R$ A
其中定义道路的句子,如下所示,是什么意思啊?
3 [, i9 [" t5 D" M1 _5 z" M; {# Z" ?) W set roads patches with
) M+ B* `& X$ [6 a- h5 r [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or9 K( p4 g8 M; x( r! S; z H. J
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 ^ _' [8 I6 ]/ R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? |
|