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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。+ E3 ]6 _2 E! f, n1 }# z
netlogo自带的social science--traffic grid这一例子当中,
% z( |1 }! @8 d% o+ E5 Zglobals3 N ~" o9 a4 T( O2 i. x, V" f
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grid-x-inc ;; the amount of patches in between two roads in the x direction- R) y) a/ `5 x% H# Y, M$ y
grid-y-inc ;; the amount of patches in between two roads in the y direction
6 L+ l( _1 M) K, K acceleration ;; the constant that controls how much a car speeds up or slows down by if* n' V, Z! N; N! a8 O
;; it is to accelerate or decelerate' G9 Y' ]/ J0 ~) U8 z6 K
phase ;; keeps track of the phase( i* a( l; |, b: Z% w
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
: W5 V; x K. t+ I1 I current-light ;; the currently selected light4 L! }* C6 b& F( Q
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;; patch agentsets4 b5 g' ?$ V8 e$ q
intersections ;; agentset containing the patches that are intersections
% g% q/ ^! {2 [5 H) ~. w& Q roads ;; agentset containing the patches that are roads! z( t0 U. [7 ]! \* r
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4 Z# P' G8 A: ^# s: vturtles-own
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8 @$ i5 T" p9 j* |% v4 r speed ;; the speed of the turtle
1 k8 K; u2 L; F& T1 ~0 ^+ [/ g up-car? ;; true if the turtle moves downwards and false if it moves to the right6 ~& ~. b1 j$ j, ~; ^5 w% ]
wait-time ;; the amount of time since the last time a turtle has moved
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9 n' A, d. C5 G* ~& _patches-own/ X. v3 i1 R" A6 O8 o9 ^. [, S
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& r! X U! v2 ^, Q intersection? ;; true if the patch is at the intersection of two roads
, r% [& z& d/ R$ i3 I! k. t3 m green-light-up? ;; true if the green light is above the intersection. otherwise, false.
: P L: N) n; | ;; false for a non-intersection patches.! N" ?2 S8 \. S0 y/ K1 c) H
my-row ;; the row of the intersection counting from the upper left corner of the
7 p; j! Z+ B9 M' } ;; world. -1 for non-intersection patches.
' t3 i5 n6 h1 c' A my-column ;; the column of the intersection counting from the upper left corner of the
0 n9 e0 Q# K7 e' n( K/ B8 ?2 u ;; world. -1 for non-intersection patches.
8 }, }) ^7 k, N/ I9 f, ] my-phase ;; the phase for the intersection. -1 for non-intersection patches.
& A/ a; \- [8 W$ Y auto? ;; whether or not this intersection will switch automatically.
# B' u7 R' C, R ;; false for non-intersection patches.
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, p+ ]7 u9 J% s;;;;;;;;;;;;;;;;;;;;;;
9 O' [. B; M5 h+ [: y& C. ];; Setup Procedures ;;5 ]( t9 U. }# @
;;;;;;;;;;;;;;;;;;;;;;
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2 t1 U4 q9 k$ z+ ~8 J3 L7 _;; Initialize the display by giving the global and patch variables initial values./ k7 R5 V" G% V7 j4 W
;; Create num-cars of turtles if there are enough road patches for one turtle to+ d+ o, D! X; q+ B
;; be created per road patch. Set up the plots.3 F8 n: n7 R8 \4 k, ? H
to setup0 x/ |, Q- f# X: t I7 K
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setup-globals
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. T# {' L/ h, t5 ~8 H r( T ;; First we ask the patches to draw themselves and set up a few variables
% |* T6 f0 D7 o) x t3 _' D setup-patches
5 A( ?9 N0 W1 \! X( ]6 Y0 e make-current one-of intersections" }: v: D: K1 B8 Z
label-current1 o/ R. q* |6 ]" Q I. J: `: k* s
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set-default-shape turtles "car"
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "/ E# [" Y- c4 A: S% I
"road. Either increase the amount of roads "
( j$ Y; W7 m# ?+ e$ K "by increasing the GRID-SIZE-X or "
1 ]- e1 @& X8 j) D2 `/ Z* A( ~ "GRID-SIZE-Y sliders, or decrease the "
' o. F# [( U# E' O' l' z; C "number of cars by lowering the NUMBER slider.\n"
# R* a8 T6 _4 o! ]- P7 k "The setup has stopped.")
& { x% M) S1 I, M' T* d stop3 t" i4 C; t. W- f) R6 g
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( i$ Y8 ^3 R1 [! @5 u. I. l ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
: L+ U- l. h8 t* |9 M J% w' w crt num-cars
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+ |# q, S. o! R3 u setup-cars+ O1 b+ W# _1 H: g) s0 V; w
set-car-color- F5 Z) W$ X3 n5 [: H/ L
record-data
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) e' J' ~/ j$ K ;; give the turtles an initial speed
$ Q/ Q5 N4 T! d- j ask turtles [ set-car-speed ]
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* u6 V6 B; r2 K: `+ B. {# {) {$ k reset-ticks3 k* e' \$ T3 W; F% a1 \, m4 Z& B
end
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# v8 x( R/ H: ~7 {2 r* O( V/ t, s;; Initialize the global variables to appropriate values
2 h0 y: `7 Q' b' Ato setup-globals
* `3 [9 v& ` Z$ `' c& W set current-light nobody ;; just for now, since there are no lights yet
; A( i; x: F" f C& u( v/ r6 ]/ s; S set phase 0; @& |, [& X% T0 s' X y
set num-cars-stopped 0
+ s# g2 W4 N5 b8 f3 ` T1 Y set grid-x-inc world-width / grid-size-x
) H9 A' ^$ r# i5 l W% K set grid-y-inc world-height / grid-size-y/ `0 j8 W0 F/ K; U0 i
; i9 Y" R; A4 p' \" f ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary! P5 |5 I% i+ A1 }8 I
set acceleration 0.099( L I- r, m2 W% ?# g5 O
end
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5 h( g3 B! b( T3 j! M3 V2 {;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
1 s+ R' T# ]' G, ~# l; R$ O;; and initialize the traffic lights to one setting
, X0 t' X& d7 B, C! I" hto setup-patches2 ^# S& y4 P6 v
;; initialize the patch-owned variables and color the patches to a base-color: n3 x9 r9 J* ]6 A
ask patches/ _/ s8 X8 X9 f
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& ]2 a' A" ^4 c, N9 j4 q set intersection? false
. J4 V! E/ L5 t2 z$ N& m1 @0 R: [7 m set auto? false
! V3 G; s7 _' L( ?8 s set green-light-up? true
! T8 P( S/ H6 p# P/ ]+ M7 v" f set my-row -1
! n) t6 l6 y- j* @" v/ b9 n set my-column -1
" m+ L. }- s/ P! b; b3 }" ] set my-phase -1# o3 ^" j" O4 i' a) A3 R5 C
set pcolor brown + 3
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0 x& K- a R5 B* E: q ;; initialize the global variables that hold patch agentsets( T: }# N& V1 n
set roads patches with
* p, }' [. V0 I K+ \3 p% }7 { [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
2 P3 w9 A( ~. q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ G: C/ @5 s) U7 v+ R! q( F8 ] set intersections roads with
& C2 h/ v* q- e' i! j [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and& k5 b5 P' a( j
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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" k# C( q- D6 r- e2 J+ W% u: M ask roads [ set pcolor white ]$ q3 T* I: a# D5 R
setup-intersections/ a. B2 u4 t7 h& t& `7 L
end
) @2 _8 O9 N8 }3 U: G$ P其中定义道路的句子,如下所示,是什么意思啊?; A* ~6 k* Y9 ^4 L
set roads patches with6 x% Z2 I5 k1 W# Q
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or: g2 z) C7 `; A& q
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) v2 V6 ~. U5 u8 Z. p7 h: ?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? |
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