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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。
1 U$ U4 u1 ~. N# }! xnetlogo自带的social science--traffic grid这一例子当中,
( b1 F: M, t) O. k" C- O7 {: vglobals, w; B/ Z2 N" B J
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grid-x-inc ;; the amount of patches in between two roads in the x direction
: c, Q+ _4 ?" A" P grid-y-inc ;; the amount of patches in between two roads in the y direction
' a) V9 H( N" [/ f6 u- v- @ acceleration ;; the constant that controls how much a car speeds up or slows down by if
* w- Q, b N' x9 _& h( } ;; it is to accelerate or decelerate, l6 B- N/ v$ h) }# B0 G. @( F
phase ;; keeps track of the phase
( C# N6 x8 t+ M& T! ], d num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
# D; M7 m: J; X7 [3 o( I% w, ` current-light ;; the currently selected light
8 ]7 F4 l& _6 \. {
9 R) }' i0 Q8 u5 q) ]5 D$ L ;; patch agentsets; r0 F, l) I! q# y! Q4 s3 d
intersections ;; agentset containing the patches that are intersections* f# }$ Z' _" k
roads ;; agentset containing the patches that are roads; c: F0 [# \4 Y* o7 j+ z
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9 p1 } I1 c1 F+ C- d) Q6 w9 o4 E$ Z' nturtles-own* z- R% p; L7 h" z
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speed ;; the speed of the turtle7 U& e) v' ]5 I/ c- W
up-car? ;; true if the turtle moves downwards and false if it moves to the right' _$ }4 B6 |0 C
wait-time ;; the amount of time since the last time a turtle has moved+ M# ~1 m" H( R' R/ r
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* d$ i( J, z7 d; @( p0 y2 upatches-own
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intersection? ;; true if the patch is at the intersection of two roads
# I. N$ R( G* } green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! \: u, q, x% C @ ;; false for a non-intersection patches.4 R& b/ m/ F' ^. G' h n5 @
my-row ;; the row of the intersection counting from the upper left corner of the! g7 P. t8 n+ j" g" P' \4 {: x; {
;; world. -1 for non-intersection patches.) g- X6 ?3 }% Z
my-column ;; the column of the intersection counting from the upper left corner of the
! C/ N( [! j) K; Q ;; world. -1 for non-intersection patches.
3 u4 m* j$ D5 ?5 Q) ~ my-phase ;; the phase for the intersection. -1 for non-intersection patches.
- |. H. v2 |6 D9 H4 u! C auto? ;; whether or not this intersection will switch automatically.
6 E8 }8 Z7 H) J- u5 K' D ;; false for non-intersection patches.
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; Z2 k( P9 W# ?* E* }3 _( u;;;;;;;;;;;;;;;;;;;;;;
! `. W( M' X! B7 X& n;; Setup Procedures ;;3 F7 L7 m" Y6 i0 X! b# y$ d
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;; Initialize the display by giving the global and patch variables initial values.
# ~) t/ c# T" H6 o. E% S7 z;; Create num-cars of turtles if there are enough road patches for one turtle to. v0 l! V5 O: C% y$ k) X
;; be created per road patch. Set up the plots.# C7 ?* m% q. z8 n' b) Q. C7 @
to setup
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% t% {# q& B; A- h- a setup-globals
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;; First we ask the patches to draw themselves and set up a few variables& p& \( f# s) f
setup-patches) X6 _. J6 D9 [8 o- o0 P
make-current one-of intersections! a# T: C) [" Z; V3 B
label-current$ ]0 Q9 P6 c9 @! |0 y6 [# b: S# l
4 \9 L2 s/ T2 X: h1 c2 {2 z set-default-shape turtles "car"$ d6 s* N" j/ \( X9 O, v2 ~
: @: p' o' g5 t, s2 l: H+ l if (num-cars > count roads)5 L0 `" ~/ x4 x9 r: i5 y" M) Z
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( t* J3 }3 W! C4 v0 @7 [ user-message (word "There are too many cars for the amount of "
k% |& h1 |2 Z. G "road. Either increase the amount of roads "! n! p, b8 Z) `+ n7 g
"by increasing the GRID-SIZE-X or "& C( W5 C% {% M
"GRID-SIZE-Y sliders, or decrease the "
& d3 G& G0 O2 p5 ^4 }: C- D "number of cars by lowering the NUMBER slider.\n" u3 B/ C$ N' a, g
"The setup has stopped.")
' a' {. R4 d% s& { stop
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! W) ~; |' V; K \0 V6 [ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
1 _# g/ o! l8 H C3 ` crt num-cars1 `2 W/ j2 Z1 K' G+ Y+ M0 D2 y
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setup-cars
5 r* s2 C( V' @, g {3 E set-car-color
2 M4 C, q4 F3 T9 w record-data+ S& K# S/ v# q7 ^
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;; give the turtles an initial speed. x( z$ _1 q8 Z4 X1 R
ask turtles [ set-car-speed ]
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1 D; ~5 X& o. A reset-ticks
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; \8 c- K4 h4 I7 Z# f7 k;; Initialize the global variables to appropriate values
# l3 S1 d8 |: S) F% }to setup-globals
* p' M9 o8 V. L0 _* W5 F set current-light nobody ;; just for now, since there are no lights yet1 [! T; q% B5 A3 R6 R& O' X% b; s/ a% d
set phase 0
: ?$ J- w* J, b5 `4 |7 v0 o1 u+ B set num-cars-stopped 0
5 ^1 n# L# @8 @/ g) o set grid-x-inc world-width / grid-size-x2 S; g. k& Q! Z/ W2 T4 S9 M
set grid-y-inc world-height / grid-size-y
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1 l' [6 d) |- Q4 T! \! z ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
6 `9 o8 C9 S1 r: A1 T+ z* l- D set acceleration 0.099+ l2 r/ o9 i+ t
end0 j* J9 ^; Z( R0 U" _* f# C& N7 w
/ z( L; w6 w6 A" s;; Make the patches have appropriate colors, set up the roads and intersections agentsets,* _+ m$ v- R( S) V
;; and initialize the traffic lights to one setting
1 m( L6 `3 c' x5 d- @# lto setup-patches+ c( i2 L4 P* c
;; initialize the patch-owned variables and color the patches to a base-color2 }( u; x- G: X L' x9 I
ask patches
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# f6 r- ]4 C( F/ O4 p, T set intersection? false
1 z5 k; D% \0 o" u0 M set auto? false y9 Q/ }+ h' |5 L; F
set green-light-up? true& m' d# P4 r% f7 x M
set my-row -1/ [6 k8 f" ^' i3 G
set my-column -11 |# h" o/ t' J; ` a4 B6 e& Z
set my-phase -17 y; | x! P, M: g
set pcolor brown + 3# Y: K/ g/ }! n4 W. I" M
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;; initialize the global variables that hold patch agentsets; u( M1 V4 N! K) F N$ Q1 X
set roads patches with+ i3 k" O4 T- |7 e! z: N
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
2 `: l. g# r3 Z0 B. V (floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 d- a2 G' G1 s- e o
set intersections roads with
% ^* S2 `2 @" q. Y" ~ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and1 R0 ?/ T) i& E' g. b
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ o: O! L3 t" V8 j
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ask roads [ set pcolor white ]
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其中定义道路的句子,如下所示,是什么意思啊?; Q6 c/ f5 e! d
set roads patches with( {" |/ e" M: q: O4 u: ?+ c( i9 s! m
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or; v4 ~# Z* v% s) _! W
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ @, a- h( ]. B. k: `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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