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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。, R2 Z4 [( d5 A' {% S. ?
netlogo自带的social science--traffic grid这一例子当中,' q' B1 i$ k5 c' ?# h5 `
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction( m, C" |* x/ F* o
grid-y-inc ;; the amount of patches in between two roads in the y direction
5 M9 \* w) \: e. [ acceleration ;; the constant that controls how much a car speeds up or slows down by if
" C0 l' |1 j4 ~. U* P3 l& w) D ;; it is to accelerate or decelerate0 \6 }6 J9 a3 a Z) e+ g, C! u
phase ;; keeps track of the phase
4 e5 w% v, Z( J num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
# j8 T+ r1 @: D1 C) ^ current-light ;; the currently selected light/ l3 q Q. ] {1 [
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;; patch agentsets
) M5 J* v a/ Y+ | intersections ;; agentset containing the patches that are intersections; i5 Y$ d f+ L" R" i \
roads ;; agentset containing the patches that are roads
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9 e. X( w8 t6 F9 o' I: q) cturtles-own( z# ]% H3 D; Z5 N
[
, C# w5 V. ~3 t0 y2 ?' T3 f3 @ speed ;; the speed of the turtle
, p; ?! Y1 F. P& i6 w4 ?" O+ Q up-car? ;; true if the turtle moves downwards and false if it moves to the right3 i! A/ D- c O- X: o+ k& ^
wait-time ;; the amount of time since the last time a turtle has moved4 k2 O. ^, n& K5 \, G" }: K
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patches-own0 c! o2 K9 {0 i$ A4 I$ ~% f
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intersection? ;; true if the patch is at the intersection of two roads- f* T9 ~* T+ U, P" I
green-light-up? ;; true if the green light is above the intersection. otherwise, false.; s# k8 y+ ~& _3 n2 n2 J/ {" y. I( Q
;; false for a non-intersection patches.- |: P0 m8 {; e4 |& {6 j7 J
my-row ;; the row of the intersection counting from the upper left corner of the! t# s2 Q. d+ N$ I/ ?
;; world. -1 for non-intersection patches.6 u" v' T, [; ^' R" G
my-column ;; the column of the intersection counting from the upper left corner of the8 R4 l$ [2 d6 L S$ l# D
;; world. -1 for non-intersection patches.2 s; e' V" r( N/ s+ r
my-phase ;; the phase for the intersection. -1 for non-intersection patches.1 X1 Q- `$ @# B, J# n& v" b
auto? ;; whether or not this intersection will switch automatically.
9 E9 _ E/ m; h/ T. C5 r( t7 \ ;; false for non-intersection patches.
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. j! l: L1 O4 W/ j9 `;;;;;;;;;;;;;;;;;;;;;;
" Y. l2 v7 `: P7 C$ _9 y;; Setup Procedures ;;# p3 }) g5 E+ G9 L' [
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
5 x' k3 ^4 g4 p& e W" O;; Create num-cars of turtles if there are enough road patches for one turtle to/ U3 I# L8 a8 r- c
;; be created per road patch. Set up the plots.7 q5 |' J; j j$ v
to setup
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
2 ?; o& @! F" X8 Z setup-patches
, M& m9 g. ?5 ]4 D$ R& s/ G R/ ]' b make-current one-of intersections
6 ~2 c7 i; c9 d5 [8 M, h label-current
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: Q# }7 P' v, C/ p! ?6 M" [. D set-default-shape turtles "car"+ R I( |: t1 G% l% @5 o
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if (num-cars > count roads)6 ~2 p. \* B2 t$ [$ J
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user-message (word "There are too many cars for the amount of "/ X3 o+ L3 {9 `, F' H
"road. Either increase the amount of roads "
3 Y0 I( j z- a+ S' P$ e% j8 u "by increasing the GRID-SIZE-X or "- _5 C% A! |) H. ~
"GRID-SIZE-Y sliders, or decrease the "
& r2 J: z# [3 h+ ?, q H "number of cars by lowering the NUMBER slider.\n" C4 i4 i: L' H( J9 _
"The setup has stopped.")
. R2 h9 ]( J5 n- X8 E! H9 Q stop
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# B% U8 d& f- Y, X ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color! X( K* c% ~2 l; t
crt num-cars
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setup-cars
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4 x) m; ^+ v X' Q" \ record-data- Y0 E. \; O% H; G: d
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& q+ b% e- v l ;; give the turtles an initial speed' T* j: e2 v% V& T
ask turtles [ set-car-speed ]
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reset-ticks
! o2 g8 B. Y: m3 \- N9 Y" Oend
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' c1 e+ _. q" D;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet" F/ K' G- `7 z
set phase 0
& I* l7 X6 j" B9 a v2 l3 d0 p set num-cars-stopped 0+ g8 ^$ H, b3 Q' \! M
set grid-x-inc world-width / grid-size-x9 L* m r1 L# u, [( _
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 boundary1 x E3 u0 j+ V- K9 Z. X2 n
set acceleration 0.099/ X! m8 N f9 X" l" H
end# n# b% v8 D+ ~* J1 X
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,8 y* ]/ U6 r3 }' O c3 s2 P- _
;; and initialize the traffic lights to one setting
4 ?2 `) j0 z- c3 X* vto setup-patches
: G/ F, P4 Z" z9 y( _ ;; initialize the patch-owned variables and color the patches to a base-color
( ?1 P( w0 a5 y0 ^4 _/ E ask patches
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* _( g7 N( D5 a/ g set intersection? false/ ]$ j' S* o8 l, ^
set auto? false
8 v" _1 V! a+ c- S7 m set green-light-up? true
& G# |% M8 S4 K, \ set my-row -10 b$ Q9 f: T; D$ m
set my-column -17 T+ T9 j P: Z% q; n- s0 \
set my-phase -1( s# |3 @" W/ ]: o- W. w
set pcolor brown + 3
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; i/ ~- @" ~8 |$ K. W ;; initialize the global variables that hold patch agentsets
% b/ G3 Z: G, v2 R6 \ set roads patches with
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+ E) e, n+ L, y7 M3 M+ G6 ~6 } (floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ z* v: L/ ~: J
set intersections roads with0 ] P: R+ m; b" O
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and" i4 C' t# {3 ?
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 g" c% ?" T- q/ Q
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ask roads [ set pcolor white ]1 u1 \' G# M: J2 o" T3 M" m; |
setup-intersections2 Y, B1 H7 Y) s5 }$ ]; l5 G
end
- E' a4 Q. D$ N* v" U0 N其中定义道路的句子,如下所示,是什么意思啊?
8 e# [4 _) ^. |: P7 n# z0 h4 J( w set roads patches with
0 J* L4 b4 ^ B v3 Z+ {" T [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or$ [& b) R# L: @" [4 M- H3 g
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
- y5 d+ v; ~' ?- @, d0 C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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