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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。
; b6 v3 N! q2 e$ b0 pnetlogo自带的social science--traffic grid这一例子当中,9 H8 G4 ]2 i" y5 c- M
globals# q, o1 {2 w& S! g
[
+ J9 C O- a4 y grid-x-inc ;; the amount of patches in between two roads in the x direction9 n+ ]& T) V* z5 v! c
grid-y-inc ;; the amount of patches in between two roads in the y direction
' }& X! B. C( K: ]* i" l+ f, ?- ~ acceleration ;; the constant that controls how much a car speeds up or slows down by if3 \- G3 @7 R/ A; y: r% @8 Y1 D1 {/ C$ m
;; it is to accelerate or decelerate+ x+ @9 P1 j/ u
phase ;; keeps track of the phase; d/ Z5 ? I" O7 R
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure4 P& s3 K5 M9 W* t. [8 q
current-light ;; the currently selected light3 w" l2 o; {: K5 {7 ~& M
# e( L8 y% M' [" V, P; [/ G ;; patch agentsets3 m. w. |; f4 ~7 y8 X; t9 i2 `
intersections ;; agentset containing the patches that are intersections: k" Q& L4 t! l7 }* N; e
roads ;; agentset containing the patches that are roads2 t& E" {) G" g& a4 E
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turtles-own
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8 k- U7 l! s% K speed ;; the speed of the turtle! S! l9 ~! ]' h' U1 i. }) {" _3 \
up-car? ;; true if the turtle moves downwards and false if it moves to the right5 M5 I" A: L% \" \3 K
wait-time ;; the amount of time since the last time a turtle has moved/ ^* l7 a/ a, w
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/ ?) F* B S6 G/ Upatches-own
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intersection? ;; true if the patch is at the intersection of two roads
! e% M' y3 ~ i, Z8 K$ }1 x green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! _) L& T/ {; f' z ;; false for a non-intersection patches.
; v/ J6 o- ~0 W# g. S) V+ u; O$ P my-row ;; the row of the intersection counting from the upper left corner of the
/ P+ p' a" O( v2 e, a3 S ;; world. -1 for non-intersection patches.
& i/ Y2 O9 q) W" q, M$ e! R J my-column ;; the column of the intersection counting from the upper left corner of the& R U, e4 S+ ?- V; |
;; world. -1 for non-intersection patches.
/ W: M9 w8 R$ ?! ?" t. N my-phase ;; the phase for the intersection. -1 for non-intersection patches.$ n1 t" T0 \' i, z) x4 E
auto? ;; whether or not this intersection will switch automatically.
+ D4 P% \& i: I( B$ ?# q0 ` ;; false for non-intersection patches.
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3 p2 `1 a7 }: }' y& G;;;;;;;;;;;;;;;;;;;;;;$ y7 s4 y0 }+ X' l* @
;; Setup Procedures ;;
. `8 A1 Q1 M. a& E3 l;;;;;;;;;;;;;;;;;;;;;;
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. }; b( j9 q w7 |. X2 i;; Initialize the display by giving the global and patch variables initial values.( ?1 {$ l8 U: n4 ~& V
;; Create num-cars of turtles if there are enough road patches for one turtle to
8 w2 Q6 e8 P! `3 u/ }3 J;; be created per road patch. Set up the plots.
& Z3 J. {) v0 z- X/ x2 c. Eto setup
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1 I6 ]) ]$ r& m" j: e7 w setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
e3 d+ x3 N8 V1 ]4 f+ l setup-patches9 N( F% S- p5 C+ D* `: g
make-current one-of intersections
' P, ]4 ~# O( d label-current
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set-default-shape turtles "car"- d2 N0 ] P' s( f
; L* i* X4 s: Y. F: \2 |% \ if (num-cars > count roads)0 u0 M" l0 ~) K9 S& ~/ h/ W3 M
[
' i2 G, g8 `7 J! w: C3 T6 G user-message (word "There are too many cars for the amount of "
9 ?# c! V. u$ E% F "road. Either increase the amount of roads " V3 y$ \$ Z0 `" w( _
"by increasing the GRID-SIZE-X or "+ A8 f# B/ X3 h" ]* h& _) r
"GRID-SIZE-Y sliders, or decrease the "3 R' \" M: c4 T
"number of cars by lowering the NUMBER slider.\n": ~0 q/ w M0 x, A9 {
"The setup has stopped.")
- d$ O# V- m# f% R+ d, `: R stop
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) a' V, M( z& P% \1 o) W* Q ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color9 }2 E+ o" J- c- x1 Z
crt num-cars8 j1 Y4 Q$ F' y9 u7 M1 S
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& d, j9 ?. {) O! Q6 `( b" H5 r4 _; p setup-cars& _" }2 b8 ^3 ?' A' p* }. U' @
set-car-color$ b0 k3 E9 X0 T$ z+ I& R
record-data' N& \, S+ T- A2 g2 Y- L j9 r$ r* j
]
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;; give the turtles an initial speed q3 m' E# t# U' o( W
ask turtles [ set-car-speed ]
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5 \" q' Y$ L2 j0 F* X7 v$ o' H reset-ticks
4 I+ v! Z: P. q4 p/ R1 i- Send
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7 q! k' U+ n) e2 n @0 O. v' i;; Initialize the global variables to appropriate values* \1 m3 b$ M; P/ W* A1 L
to setup-globals( q% I1 h6 S- `4 ]
set current-light nobody ;; just for now, since there are no lights yet
' f C" V& M0 e4 f' b5 A) h set phase 08 M& i+ q) w( E+ M% O( c3 k7 J6 e
set num-cars-stopped 0
% W x4 }! |; d- J1 i, P: [% E set grid-x-inc world-width / grid-size-x
1 a+ W# o3 v7 H" S% u set grid-y-inc world-height / grid-size-y9 d9 _! b, ?2 ]; o; l4 M
/ t2 v x+ e2 j ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary4 _8 }! |, D: K( K* m
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,! \0 K% _3 [* g$ c2 P; H
;; and initialize the traffic lights to one setting% Z; N+ m% H+ ^
to setup-patches
: y6 E3 G% \8 j0 S- R ;; initialize the patch-owned variables and color the patches to a base-color
5 j5 E$ w# t. W. ^: w ask patches
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set intersection? false3 y9 \1 O/ p+ j8 U5 n
set auto? false
" O% F' i$ S; V9 Z; ?1 v set green-light-up? true' z9 Y8 X( J6 [" |& f
set my-row -1
& d8 s4 P& C7 L1 ?; L7 B* g: |- L/ | set my-column -1/ L: k/ f6 ?7 i0 P! _' I4 H- j K! ~2 `
set my-phase -1" [1 [/ [8 j3 l; _
set pcolor brown + 3 I6 L* x: e. w8 ]
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" H8 a6 m# _6 `% ~ ;; initialize the global variables that hold patch agentsets
) |* {% y* o, J- y$ z set roads patches with4 _& Y+ I6 X/ R0 \! L, S* }- W5 P
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or/ }7 E# c. z2 n, ]$ f! [1 B; u
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 D, W; m9 c. _$ i1 i! k6 [
set intersections roads with8 ]1 b. w: X1 t7 y
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and- U. }) Q! T) H U7 i
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 c+ E8 ~: n( E- g' l
: Y) q6 T+ J3 N! i7 e ask roads [ set pcolor white ]0 B1 a3 k, p! M4 @ k! [% w
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?5 u9 S- p& k- w+ V0 A9 @/ d: C5 S
set roads patches with/ d. t; R. C- D1 L/ i
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or3 V. ~; P+ T3 ?; h, }- U3 [8 _
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; I: R5 s, \/ l+ g5 Y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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