|
|
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。$ a: O: J6 L. g% A$ N
netlogo自带的social science--traffic grid这一例子当中,
) A+ X2 z' b `5 u8 ~globals
! _8 F% e$ p+ C& w0 ^[) ^, S, j: o- F4 T) h6 t
grid-x-inc ;; the amount of patches in between two roads in the x direction
1 H1 M7 T5 Y: F+ }5 M$ G( z: P grid-y-inc ;; the amount of patches in between two roads in the y direction
6 l$ ]3 Y7 b% s: d acceleration ;; the constant that controls how much a car speeds up or slows down by if
0 p/ v9 n9 C, u ;; it is to accelerate or decelerate3 r5 W4 M" Z% B. o/ ~
phase ;; keeps track of the phase
8 {5 N8 a" ~0 ?. G; c6 o num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
, R( }9 o! O; e0 X5 t current-light ;; the currently selected light& R7 {$ A! ^ P
1 P2 Q7 w/ x8 a! J ;; patch agentsets
4 K* I, u4 t- o) E intersections ;; agentset containing the patches that are intersections
& h- |& s V* N8 [ roads ;; agentset containing the patches that are roads9 o. ?" p) _% O2 O
]
+ o3 E4 j4 O; K% j, ^( }0 L8 e/ d% }! D: `" c0 p; c
turtles-own
9 d* l' ]" B3 C( |[
, n1 @6 |2 z9 F( U9 e3 V6 f0 Y+ s speed ;; the speed of the turtle
5 ?, c+ D3 x) C4 ] up-car? ;; true if the turtle moves downwards and false if it moves to the right
1 J/ L" x% K) j, F) B9 g) O wait-time ;; the amount of time since the last time a turtle has moved
: ^9 A% ]* N) ?* Y4 {7 I]$ ]& [% n$ }9 m2 a, s5 |4 \
" p5 ^8 {/ y; U- qpatches-own
+ P$ m4 I! S$ Z: V% Q# N. l0 l% S[( R# K) O# D) M) h% [* c: S
intersection? ;; true if the patch is at the intersection of two roads
/ M/ R3 O& J; z- J. d: F" F0 y green-light-up? ;; true if the green light is above the intersection. otherwise, false.- Y8 \% {, t4 }( V# ]% q
;; false for a non-intersection patches.1 L7 N# W' s& @* D7 K5 u- y; {1 s
my-row ;; the row of the intersection counting from the upper left corner of the
1 O6 \+ u; B3 h ;; world. -1 for non-intersection patches.3 |$ J. t9 U8 Z# r0 v
my-column ;; the column of the intersection counting from the upper left corner of the
\0 ]* `6 Z3 n/ ]. w ;; world. -1 for non-intersection patches.9 T r; F! O j$ R
my-phase ;; the phase for the intersection. -1 for non-intersection patches.+ X5 v) e) R: ?" ^' Z& X
auto? ;; whether or not this intersection will switch automatically.* J1 Q% j, m: S. s9 h& D
;; false for non-intersection patches.1 [' _8 ~+ i" H+ F, _* Y
]2 e- x4 K" F8 ~
8 V, F- j& Y% Z
/ G+ O7 q' g6 e6 q
;;;;;;;;;;;;;;;;;;;;;;
0 C) Z" F$ s! F7 g;; Setup Procedures ;;
- h' h; @) d+ Z* i3 q;;;;;;;;;;;;;;;;;;;;;;
1 c6 B( G3 x9 W2 j' e s! T+ h$ ]( J# x5 @1 c: p. k1 X# w+ s9 T
;; Initialize the display by giving the global and patch variables initial values.
+ e+ U( o, E3 t" _' _& v% a8 u;; Create num-cars of turtles if there are enough road patches for one turtle to
' _. c4 a4 `% E; u0 e7 S;; be created per road patch. Set up the plots.4 x! D! g# c' F( }' g9 M
to setup
0 x3 q- m# h' M3 ? ca
1 I3 z" g5 H# S. W setup-globals
" l- Z9 K) @0 }, q/ f) A& F) b7 Y& Z$ A+ O" u7 |
;; First we ask the patches to draw themselves and set up a few variables
* x# e7 X/ @' @ setup-patches
X2 v6 E& I$ d3 J make-current one-of intersections
/ w' K% Y9 V7 b& H- O label-current1 w m J& f' s1 |% j5 S& F1 r1 p
, ?, B" O' ]( i9 D5 C
set-default-shape turtles "car" i9 t; V5 t* q, R
5 [5 i" j7 n9 B- ?
if (num-cars > count roads)
/ V; F" X v8 W& }% | [
* y4 U3 Z; C4 W# N user-message (word "There are too many cars for the amount of "0 _" X M. Q3 Q1 Y
"road. Either increase the amount of roads "
! O9 J6 _* `/ b* `6 s1 w) G "by increasing the GRID-SIZE-X or "
9 o* I) ^9 f" Q; R "GRID-SIZE-Y sliders, or decrease the "8 w% T0 y" p7 v6 X+ Y, y5 l
"number of cars by lowering the NUMBER slider.\n"
7 O' w: ~# O' Z5 |+ r "The setup has stopped.")
, b) G& O; U+ I, p+ y stop
1 ]/ W1 X! g, @! z4 S0 o ]
( G4 m# [, r% j% K) F7 n2 I. p- l! i% b. Z9 R6 X
;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
% u0 s0 w: s+ S" Y; c) m1 ?5 Y/ f crt num-cars6 I1 u5 e R$ _+ C, @
[ d4 E' c. b, U j3 X3 q$ Z
setup-cars$ l1 _9 x/ d' T# r% p9 w2 Z! k7 O0 ?
set-car-color- J' d+ p3 v. ^8 b7 h E5 ]: [
record-data D L) ]9 E" w$ H+ y' ^* m; }+ s
]" Z2 [! Z% u, J. S$ n5 T
5 b0 @! _2 S+ f, E% A5 a* ^. V ;; give the turtles an initial speed1 r8 u. m# M7 Q: x9 m& P' X. z
ask turtles [ set-car-speed ]( V9 ]5 g j; S1 i
Q, t. Q6 z4 S# X. ?* x3 z3 N reset-ticks
; C, w" |* L% send; U; N5 U' U, v3 l6 I% I
5 C0 U( J$ ]0 b1 e;; Initialize the global variables to appropriate values9 [. L9 `0 e8 |' M Z/ J8 q
to setup-globals g# M3 q3 A3 C4 `
set current-light nobody ;; just for now, since there are no lights yet' C# _9 H0 |/ ?3 I- @
set phase 07 D5 D) s+ {6 b) s6 x9 ~ b
set num-cars-stopped 0$ ~' p2 M/ L' |: R1 N0 _, }- w( f( Q
set grid-x-inc world-width / grid-size-x/ ^$ K0 x9 b C; l& W3 e) m! Y; D
set grid-y-inc world-height / grid-size-y
6 m( i# M$ \% B' @: v
- X$ c+ Z' y k% y* j ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary% e! W9 I5 q4 p% z( e, I
set acceleration 0.099
- y" W& M* z1 A6 Eend3 u9 A3 y; }$ w( U
0 @) W$ L" a, n: M4 v% z6 Y( ?! x6 U
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
" D4 A! Q/ B. @" b! h;; and initialize the traffic lights to one setting
- G% \6 j3 o& C% jto setup-patches2 g/ H1 \# _) T2 e; J# R
;; initialize the patch-owned variables and color the patches to a base-color
" X+ @/ A& c: Z# @; u4 t2 s7 V ask patches6 w. f2 B* q) C l5 X9 x( A. P( z
[
7 W+ i6 Z. L0 l! t z set intersection? false0 D! U4 n9 u/ p4 J% {# t7 w! l$ k
set auto? false) {4 v5 [* `% p2 r
set green-light-up? true
1 p+ X! Z! c. ?2 w, h0 ~$ T, S2 b3 a set my-row -1: @" I3 `) C0 p
set my-column -1
5 W2 G j- `* ~+ ~ set my-phase -1
! ?% d- o3 j( z* Q, h set pcolor brown + 34 v: U' V b7 U5 X Q6 W* B+ D8 g4 u
]
i* l6 U7 w* H) w; i6 Y, V1 _8 U6 h2 S( y8 `3 j
;; initialize the global variables that hold patch agentsets
8 t+ Q2 J! u5 ]/ F$ T& ?5 i' }2 r set roads patches with
' ~6 M6 e6 S+ K; W [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% o, p: Z) W: C7 N2 t7 [, l& A
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 h) Q9 M- K8 t8 |4 U
set intersections roads with
8 }% E- {' |, v3 i# w+ g% m [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
3 T* o4 l2 E8 i' ^: Z7 R (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
& [2 e7 K% U4 `+ p1 B" d/ O5 H$ \% M, x& [- z. Y T) X
ask roads [ set pcolor white ]5 I0 K, O( I6 ^0 f0 N" g ^8 H: K
setup-intersections' o6 z7 d8 g" H
end, k a9 j- d: Q/ P% }5 A6 x
其中定义道路的句子,如下所示,是什么意思啊?3 O Z9 k' j- b+ Y4 D
set roads patches with
$ ~. m5 A. v# E4 F, W" ?2 g, X [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
; u$ ^/ F7 O: N- N2 E (floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 b) n" l; ?8 C+ o9 y- d% D* A
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? |
|