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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。
0 y ~: U+ j! ~! i- J4 V8 snetlogo自带的social science--traffic grid这一例子当中,
, r+ C, g) d% U- ~2 `globals
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5 E6 S7 n" b" f2 q, [& c# [ grid-x-inc ;; the amount of patches in between two roads in the x direction
/ z( [8 ^& Z& D grid-y-inc ;; the amount of patches in between two roads in the y direction
. w0 y# I& i& p( i* k3 K1 v acceleration ;; the constant that controls how much a car speeds up or slows down by if
8 q# C/ z* f/ y3 O9 r) X3 O ;; it is to accelerate or decelerate
* e% n+ |6 O$ N* T$ k! y; { phase ;; keeps track of the phase6 Y; B. ~. @/ I( R: t) f c% Y
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
" z( ~. v2 U& Q* z- S current-light ;; the currently selected light4 h) i; a% x4 ?8 P1 J+ N
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;; patch agentsets
% a) \* Z8 K/ X" U9 u5 ] intersections ;; agentset containing the patches that are intersections; [1 F; h1 [0 w( C7 {) y
roads ;; agentset containing the patches that are roads
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9 F/ ^+ X V3 @* Nturtles-own
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speed ;; the speed of the turtle
+ A2 u& C7 N) H+ i0 u9 u" R up-car? ;; true if the turtle moves downwards and false if it moves to the right
0 m! u9 M' ~! y+ Y- \8 O wait-time ;; the amount of time since the last time a turtle has moved
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" A* V- F$ ?5 z; ~2 V9 V& m, Opatches-own" [/ B& J1 x2 s# i* b
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intersection? ;; true if the patch is at the intersection of two roads
8 l% I' m) f0 H7 p4 x* O' ^9 | green-light-up? ;; true if the green light is above the intersection. otherwise, false.' V q2 J7 j) l
;; false for a non-intersection patches.
+ y: f8 V$ B' \1 e$ M my-row ;; the row of the intersection counting from the upper left corner of the
: W) w) c: g0 r4 ^7 i ;; world. -1 for non-intersection patches.
# j m4 J% u& w- C0 W( R5 m my-column ;; the column of the intersection counting from the upper left corner of the
* i% o. B, R5 M$ b) s, w! q ;; world. -1 for non-intersection patches.
7 `( H6 r6 b T" c6 f) N* U& z6 k my-phase ;; the phase for the intersection. -1 for non-intersection patches.- |0 q8 w8 _& l7 @9 s6 T
auto? ;; whether or not this intersection will switch automatically.
! }& e5 [- L+ W7 R ;; false for non-intersection patches.4 p# m; P, A" I$ T. u, I" w
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;;;;;;;;;;;;;;;;;;;;;;: w: ~+ A. ~( `1 U G) b% p$ ~. m: R& I
;; Setup Procedures ;;
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* A7 v4 D: `+ t0 A& g;; Initialize the display by giving the global and patch variables initial values.1 V5 l' n' C' Y; x0 i# m+ `% t
;; Create num-cars of turtles if there are enough road patches for one turtle to& [, z) Y1 F% m- T
;; be created per road patch. Set up the plots.! T9 J- X- }) }+ Z9 n* i9 U
to setup
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! {$ n) c( O! q setup-globals, t4 D/ O M* a! S1 c
- `+ e1 K3 d: G% d& |! R ;; First we ask the patches to draw themselves and set up a few variables
6 v% j) T3 ?6 @ _8 [+ S' w- ^ ? setup-patches
?- k s) B' b* t make-current one-of intersections- E$ t! z- g$ w
label-current0 H! ^6 [2 `* w$ ^0 f* D7 j; p
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set-default-shape turtles "car". w6 f- v+ Q, _, N
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if (num-cars > count roads)" h$ k& U4 h5 Z: ]
[
' \: f: W/ `1 U; V7 c user-message (word "There are too many cars for the amount of "
; q6 H# J% ?7 P* |& j/ n" S "road. Either increase the amount of roads "' O* w. w+ t; U
"by increasing the GRID-SIZE-X or "
; G* d {7 P5 v2 H: F# e "GRID-SIZE-Y sliders, or decrease the "
; K l' ]4 m- n/ @* J( |+ p% | "number of cars by lowering the NUMBER slider.\n"
9 a' Z" d' D3 ^( I4 H7 T) ^) p "The setup has stopped.")
8 d) G( X# Z6 q6 j! R stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color% }, s" y' M! x2 @. l% ^3 H
crt num-cars
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- e j# i1 P2 p4 L; @5 J setup-cars% s: Y! V+ b; b# r7 g
set-car-color
T4 \# A% }/ `3 `* P' b3 @2 `9 R record-data
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;; give the turtles an initial speed$ d# o/ ~! t; B3 ~# Z2 Y
ask turtles [ set-car-speed ]& y5 r9 i% i2 }3 ^ b6 T7 ~2 e M
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reset-ticks
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5 i7 Y6 Q& `. ]7 t* y3 v1 l4 x B;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
% ^# p; y" l. b set phase 0- ?' ?: i o) G. p$ R1 X9 `6 s& F
set num-cars-stopped 0
. o/ v% ]1 Z! ~ set grid-x-inc world-width / grid-size-x% Q$ @% ^* v! ]% J F$ r4 K: o
set grid-y-inc world-height / grid-size-y2 l: P( j) D! J) ?; g. A
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
2 A- C/ `$ c3 v set acceleration 0.099# \& N" _8 g8 `5 Y/ o* G$ A
end8 A/ e6 M% \4 e/ J
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
0 ?* }7 ]' `0 m$ k% W6 L1 _;; and initialize the traffic lights to one setting
0 f3 E3 P- {) v: Uto setup-patches
: q$ Q6 C* t" D2 G9 H0 ?/ t+ K ;; initialize the patch-owned variables and color the patches to a base-color
- M8 j8 N) s9 ~) r3 y ask patches
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9 `$ L! _1 s& Y6 C2 u set intersection? false
9 n; S/ x6 t" Y: y- E set auto? false+ ]) A& l& J, t" \. N" k s8 D
set green-light-up? true/ T! P6 ?5 A8 p7 [, U2 i
set my-row -1
( D; t% @; N) \6 b1 K set my-column -18 B, |9 K7 _8 q. l
set my-phase -1
/ m. h. Q" h3 W5 D# m: |" U$ } set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
) `1 o7 Z& u- Y5 \$ F1 t set roads patches with. F- X3 @: O# s/ M+ w7 c9 L. @
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
( E( y h% F' q7 p (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ Q1 l4 g4 U a% F set intersections roads with' Y. T8 |- ^1 C/ y( Q# @
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and4 V$ S/ X; X. ~8 `
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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" I/ W1 @ s6 w5 Q$ X: N3 S ask roads [ set pcolor white ]! f; w$ K3 v3 `
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?0 l1 J+ y1 k# c* Q6 K+ n
set roads patches with% ?$ m5 u- i3 t2 N
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' M/ F, Z# q7 Y" f! ?( l% y7 N (floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 p* s' d) W# ^8 |1 Z* 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? |
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