|
|
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。7 N" H/ Q+ _# p0 f9 H
netlogo自带的social science--traffic grid这一例子当中,
" O3 U. [5 I5 b# B% g, ?/ Eglobals) c9 n) U! E, A+ r5 _
[5 j' h4 ~% v3 C$ n
grid-x-inc ;; the amount of patches in between two roads in the x direction% G$ V* X; e3 Y8 j; g
grid-y-inc ;; the amount of patches in between two roads in the y direction4 l% n5 @1 |) Q" D. N
acceleration ;; the constant that controls how much a car speeds up or slows down by if
: y; ^% M7 ?0 ^- p8 ^, ] ;; it is to accelerate or decelerate+ c" L V8 G6 v j' t6 G
phase ;; keeps track of the phase
; F: @+ Z* D+ r1 h% s num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure, N+ R* B+ ` {) {# R
current-light ;; the currently selected light5 q d2 q5 T; x
! z r k$ G3 Q2 B ;; patch agentsets! z) |! z; r" P: I3 D/ v$ m
intersections ;; agentset containing the patches that are intersections
, P8 M$ ~4 f, m roads ;; agentset containing the patches that are roads& i( T, q% N4 N
]8 y7 h. a% L( U, Q' O
' M$ t2 F5 ]/ S+ ^0 ~- e7 Bturtles-own
) ]7 Q5 `) {6 n5 |- D0 O4 O/ J[
8 X0 c$ W4 t4 O8 O6 i speed ;; the speed of the turtle
% k* s1 L r0 v up-car? ;; true if the turtle moves downwards and false if it moves to the right6 x3 K- C! x% d7 N, x) i
wait-time ;; the amount of time since the last time a turtle has moved
2 o" W! Y# [6 t5 r]
' o" K* z" s0 V1 j( @3 v" p; X6 i5 i7 O
patches-own
4 ?6 N K: ^# L9 _0 E! C6 B[5 r0 q! M& K# g8 O
intersection? ;; true if the patch is at the intersection of two roads
! i5 a2 B# m$ W* g green-light-up? ;; true if the green light is above the intersection. otherwise, false.5 m* P6 U! X+ G; [, @ g7 O
;; false for a non-intersection patches.5 `7 t) A. [3 \# p/ \7 F: {
my-row ;; the row of the intersection counting from the upper left corner of the
6 ^ R/ ?0 J# m( G" i7 Z ;; world. -1 for non-intersection patches.; P9 {! {( k2 v5 z
my-column ;; the column of the intersection counting from the upper left corner of the, n9 G# }* u/ _
;; world. -1 for non-intersection patches.
# a ^0 F6 Q1 D, A my-phase ;; the phase for the intersection. -1 for non-intersection patches.
. P+ F* ~* `% W- I5 A8 b auto? ;; whether or not this intersection will switch automatically.; X2 G" Y+ ?' D. D( n& w4 F& b
;; false for non-intersection patches.
! Q* S& c* i; h]9 H7 C4 j" R/ R0 P% o$ F
- g+ }2 y2 F/ b, D6 E3 M$ |- M; I) z0 x8 ?- R) V* Q
;;;;;;;;;;;;;;;;;;;;;;
: n+ p3 P4 U* H& e3 P1 e3 D5 Z;; Setup Procedures ;;
1 z2 x. e% C% R' {* L7 C;;;;;;;;;;;;;;;;;;;;;;
5 x# p. f% j- b3 O% u9 p# f4 ^5 V8 {- J' M! [
;; Initialize the display by giving the global and patch variables initial values. M# G: R/ a: m+ `% o+ [
;; Create num-cars of turtles if there are enough road patches for one turtle to
G$ A1 b. P- u; w;; be created per road patch. Set up the plots.
/ t3 h1 ~, f, e; ^) K3 jto setup/ X" _8 B$ a5 | @8 r! o
ca1 b7 _# A9 Y! @; _! U0 S" M8 _% t
setup-globals+ w+ ^% F, i; g
w+ n0 O0 z5 s: ?' X" Q
;; First we ask the patches to draw themselves and set up a few variables
7 o5 L L& q9 s1 Y8 I: s4 d2 Z0 N7 D setup-patches8 w6 I. P+ \/ |" O; F
make-current one-of intersections8 r( r, O+ E% I0 ~! Q2 u7 q0 o- z
label-current/ ?* C. V6 n* P
5 J8 X& [2 i8 u8 S- ]! v& k" V
set-default-shape turtles "car"
# D# f, D0 @% q, }: p# u
; Y7 d" F n8 a% G6 F6 | if (num-cars > count roads)) T# C. g* R. b u% u+ p
[0 M1 A$ y1 O' `6 p1 A& h
user-message (word "There are too many cars for the amount of "
( J- U9 L& `9 Y% ~& E9 k( v6 Z "road. Either increase the amount of roads "' s- t" W9 Y" F0 `% j6 a
"by increasing the GRID-SIZE-X or "
! l. o( J, ~1 A/ H" @+ w "GRID-SIZE-Y sliders, or decrease the "" ?+ \8 x6 s- i. k% k3 T l. y
"number of cars by lowering the NUMBER slider.\n"
! e- L. B! s! T% h "The setup has stopped.")0 s; T, P* J) F% A' Z
stop
/ ?4 i6 M8 ~. `* l ]
0 y% P/ d+ N* t$ F" @- J# R. U: L. g2 G' F7 m8 ~# W6 t
;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color6 t- w3 R0 \6 S& a8 q% [
crt num-cars( h/ c( L; H5 _( P9 E' G
[/ e8 I; f2 R; k A2 u; B
setup-cars
, E8 L! Y. D. O9 d0 x; R/ j set-car-color
H9 o# o* R) b: C- W record-data
0 b/ ?1 W2 ? u: M8 _ ]5 X# s/ `% l: ~+ L( W
2 i& s. ?/ ~! I! r3 `$ p ;; give the turtles an initial speed
" n1 J( i8 K- _ ask turtles [ set-car-speed ]
, |; G( M1 n. ?
. u! @$ V1 z" u# q" k' k6 J- z reset-ticks4 a) j6 x( F$ ^' p' R$ c8 _
end
8 t$ k& O' j% G& ?4 B5 c
9 N- F& c# d- X2 w4 n% @;; Initialize the global variables to appropriate values
/ P: Q. c4 q( E, H* Y/ u, [2 ~0 d8 y( R# Mto setup-globals B6 R5 s+ C8 |% O% a( e( P
set current-light nobody ;; just for now, since there are no lights yet% |* [! @5 r8 d9 J8 U4 }5 B5 R1 n
set phase 0
$ f; G3 z; S" E! P9 \ set num-cars-stopped 0
6 A6 N2 X. S( | set grid-x-inc world-width / grid-size-x
% O, m3 J( @+ A$ }' m& }5 }+ F; S1 I set grid-y-inc world-height / grid-size-y5 r* a* D4 K% [( n0 P2 s( J
) D1 |( A+ R. O6 g' o ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary: Y1 Y2 R! |( E: v+ }" ~
set acceleration 0.099
7 \1 Z* z9 S- U5 y0 Mend7 [: W- V P$ V- J, I. W
0 t w, ^# C" m8 ^9 V" [ J;; Make the patches have appropriate colors, set up the roads and intersections agentsets,/ J- G$ y: p7 }- c# U5 S
;; and initialize the traffic lights to one setting
/ T( T3 V) [% \5 Nto setup-patches6 H; r9 c4 [% [% P# r# ^
;; initialize the patch-owned variables and color the patches to a base-color. F# B, x& n9 g+ x
ask patches+ z& E* W: P) v% N, S. k
[
5 U; u( Q; n' D2 j. V0 n set intersection? false# {$ Z3 ^3 g6 z" j7 E1 F; b# G* I
set auto? false5 n5 c( y: B; u1 n; z, m
set green-light-up? true/ L. {; l! @. I
set my-row -12 z% }2 M4 B. p
set my-column -1' t2 W3 ?# q6 O' _# G
set my-phase -1
! k" o# T" n) I# N7 f. r: Z set pcolor brown + 3
( {% d, z( {5 o: v) J3 @& O) l ]
/ H7 o7 o( Z7 ~9 _6 n6 ]
. P# |" n8 ?3 B6 `- r7 n: D- M ;; initialize the global variables that hold patch agentsets1 H9 k# N& |4 K
set roads patches with9 b' j( [9 `8 V) |, b
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 B. V3 V4 k# R& y( x0 G (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
& O. C5 y6 q' r set intersections roads with3 i6 @4 {: U. `* [, ~) s+ W1 l
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and7 H# w5 o, U4 n7 M( U9 k8 o$ h
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ I6 k' @& U; y2 T' }! ^) w( ^
* B7 b" T4 C/ _! g* i- e% q
ask roads [ set pcolor white ]
" p$ s" I- l' I' d setup-intersections) R: B# Z/ U3 G8 J- _
end% Q8 ?: \# I: Y& S+ } o% P* \8 ?* B" e
其中定义道路的句子,如下所示,是什么意思啊?
1 ] g: s$ H; `# e- @/ Q$ _. o set roads patches with
& O- u: M8 B) r4 K1 P [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 ?- \6 Y+ n$ t' g! U3 u (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 l7 {& g7 l7 @* L" j k$ c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? |
|