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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。
: w2 T0 c8 z7 u$ \netlogo自带的social science--traffic grid这一例子当中,
1 S" n2 ?, }6 i3 Q3 y4 e; a) X' M1 \globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
3 V2 Z" V9 D0 p& [6 n$ u9 w: Q+ I grid-y-inc ;; the amount of patches in between two roads in the y direction
; v. P) T2 n: K$ n- ` acceleration ;; the constant that controls how much a car speeds up or slows down by if3 _) M! p! A: b \( |9 ~, J* v$ C
;; it is to accelerate or decelerate2 N; Y$ P5 q( l0 t' H
phase ;; keeps track of the phase D" i( H2 ]* f6 c( d/ c9 E4 v
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure: i7 a l$ V# w* j4 K: M" }
current-light ;; the currently selected light
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. z, o* A6 |2 k+ W; g. w& @ ;; patch agentsets9 t+ |! R w$ F* ~
intersections ;; agentset containing the patches that are intersections0 A0 x% h' h! s }5 o: _8 I( I* W
roads ;; agentset containing the patches that are roads
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turtles-own$ g1 @- k4 r' Q. A1 D& D5 x
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speed ;; the speed of the turtle
" X2 K& S6 s' _ up-car? ;; true if the turtle moves downwards and false if it moves to the right- x, H5 w- I$ i
wait-time ;; the amount of time since the last time a turtle has moved: K1 |/ H0 `+ _7 L( Q- q
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' W% k% S0 u7 Lpatches-own3 q8 j6 n7 ~3 Z3 l& l J6 l, n
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intersection? ;; true if the patch is at the intersection of two roads
, x* G! S3 d7 d" S& Y" Y$ n green-light-up? ;; true if the green light is above the intersection. otherwise, false. u6 H( M8 X U7 ^' ?
;; false for a non-intersection patches.
' Q3 h/ u7 w p$ Y# ^ my-row ;; the row of the intersection counting from the upper left corner of the4 C9 n! i" |7 U4 E
;; world. -1 for non-intersection patches.
9 _" {8 Z& ^9 [ my-column ;; the column of the intersection counting from the upper left corner of the
* N4 q% F3 Y X) a5 @4 }. i ;; world. -1 for non-intersection patches.& r% n. ~! w, m0 @9 U8 |2 V5 ^( \3 P
my-phase ;; the phase for the intersection. -1 for non-intersection patches.- O! o( N9 ^5 X( p* M
auto? ;; whether or not this intersection will switch automatically.- B7 w: i# C( v' g
;; false for non-intersection patches. I0 a4 f; j, x( u, G" M2 ~
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;;;;;;;;;;;;;;;;;;;;;;
8 S* @& f. W7 n. ];; Setup Procedures ;;5 X3 v; c3 p5 |6 n1 W/ U+ G
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;; Initialize the display by giving the global and patch variables initial values. l$ C! N0 u# b8 _
;; Create num-cars of turtles if there are enough road patches for one turtle to Q. D3 F/ m0 p/ T# C9 g
;; be created per road patch. Set up the plots.
# a7 Y+ N% V m0 G: i4 E$ r2 z2 J& }) Qto setup; v. @$ U7 G* \$ ?3 Q S
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setup-globals4 s: ?: {7 G% e" w0 _, @
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;; First we ask the patches to draw themselves and set up a few variables5 I+ u; K2 d1 B6 a% |; d- L
setup-patches
* O' q! C |# a2 c2 ` make-current one-of intersections) p' E' ^4 f8 L( [
label-current7 ~4 S1 Y; z. E
: Q) X' f0 [0 N7 `9 R set-default-shape turtles "car"$ G. V {8 v+ K# C! k9 R
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if (num-cars > count roads)
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1 n& C* m7 V# e$ W4 u* O% M user-message (word "There are too many cars for the amount of "3 g1 q$ R; X6 p. s" e) n, y5 l
"road. Either increase the amount of roads "
* D V; l3 z) M* n "by increasing the GRID-SIZE-X or "
* @% G+ H3 J' q5 E8 d "GRID-SIZE-Y sliders, or decrease the "
7 j y# Y4 l$ H# y "number of cars by lowering the NUMBER slider.\n"
: Q2 x# W% D4 Z* o6 T8 D "The setup has stopped.")
3 N& j, i( h' S- \ j6 F6 N stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
/ x. a. ~5 f$ Y, ^: k/ z crt num-cars
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setup-cars
0 G5 \$ M. j6 L- l set-car-color
9 V0 [( N1 `) n; K: n record-data. w: x/ A8 n+ U2 }$ P% E: O. s7 M& V" L4 s
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0 U/ M3 E" G0 z: `! J+ x9 }( D! y/ x ;; give the turtles an initial speed3 N: j3 O- n7 J$ k) f
ask turtles [ set-car-speed ]
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reset-ticks, K7 s, E! w: e2 L Z# p: w
end# i" l3 l! L6 w. v+ w' {
# {: t7 ^" T% W; n" T;; Initialize the global variables to appropriate values
+ i) A2 M1 V# J% y+ |5 E4 s8 R' Ito setup-globals. p& j, \7 ?+ s# G- t
set current-light nobody ;; just for now, since there are no lights yet
: D$ i/ d) e( ^, } set phase 0
: s7 A6 J" \" \+ n* c" ~1 p set num-cars-stopped 0
6 s) \ W" c4 y. y( o: B; R5 J8 a set grid-x-inc world-width / grid-size-x( s8 B3 I5 {6 L9 p) U+ E- x
set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
; z3 y0 E/ H8 g7 z( l+ n% J set acceleration 0.099
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5 I- L: h% U" A1 |;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
( n7 z% F' }9 b8 m8 n;; and initialize the traffic lights to one setting
3 a8 F% Z) a# U3 b& g6 J. Vto setup-patches- n, ?. B4 d7 Q0 y) z3 t
;; initialize the patch-owned variables and color the patches to a base-color" C4 c# w7 l! E6 j
ask patches a7 v* c5 W3 G6 J# ]5 F
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set intersection? false
2 J; q B" m7 X& Y' W( Z set auto? false
* [* |8 _0 o7 | set green-light-up? true% Q- J! }3 e, Y
set my-row -1
( m& T# b; W# e' u. x; ]1 U6 e2 U set my-column -1
# e" P7 `- v! K- V) I4 R- H' n7 ? set my-phase -1
: D9 }( {" n8 I8 Z& [1 K' j+ ` set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets9 ~! h* E8 e9 y @) }
set roads patches with
/ ~- X" O6 T7 p8 l3 D9 x [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
. M, ]6 }: E5 J, z' p! p- } (floor((pycor + max-pycor) mod grid-y-inc) = 0)]) k3 z" [9 p6 l9 n! }
set intersections roads with
1 e; K9 W4 P7 E [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
$ l% Q x* `" ?' c. E- e3 b% y (floor((pycor + max-pycor) mod grid-y-inc) = 0)], [! ]. n/ J4 Y1 ?
. N( P8 s* v% h" M2 R+ A! Y ask roads [ set pcolor white ]
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end
* @9 N6 ~/ L6 ?9 y6 Z其中定义道路的句子,如下所示,是什么意思啊?
- Q& {: |+ P: b" t$ p" i! A7 ] {* ^ set roads patches with
: c' E( s7 ^. [/ ` [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
- ?' a6 C- Z; W7 S0 ~" F! ` (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
4 D# K, i( c9 z/ z' _' ~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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