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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。
7 B) P% r L* ?$ S2 ~netlogo自带的social science--traffic grid这一例子当中,, I( Z$ T @/ ^% P: i
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
- n3 I) |) ]) G: \4 b grid-y-inc ;; the amount of patches in between two roads in the y direction
( Y' }3 ]. i5 [ acceleration ;; the constant that controls how much a car speeds up or slows down by if4 w8 ]% a9 a( |" h
;; it is to accelerate or decelerate
; k+ @6 X7 h0 d+ z phase ;; keeps track of the phase' }8 [$ X; d" T" M) i& z, t+ G
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure& Y% t" h% R+ O) b0 A, G0 l% z7 M
current-light ;; the currently selected light z) t& k# `3 w/ [% N. q
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;; patch agentsets! s9 x! u( `. A; J* N5 P5 `9 T- V* V# l
intersections ;; agentset containing the patches that are intersections
. w* f. u) w2 Z* _- W( E roads ;; agentset containing the patches that are roads0 `2 s- l; d& R$ s1 n; h
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turtles-own
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6 w2 ]+ E7 h- u4 L0 [9 |2 z speed ;; the speed of the turtle/ [1 }6 G" a: [4 ~3 L. T
up-car? ;; true if the turtle moves downwards and false if it moves to the right- W8 [+ A3 Y5 H' _
wait-time ;; the amount of time since the last time a turtle has moved4 X* F, I T/ G* w9 g
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6 k8 o3 ~+ F/ [! P/ B' w9 W6 Jpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
4 V F! ^+ W' x) r8 O8 t green-light-up? ;; true if the green light is above the intersection. otherwise, false.+ q p5 m" Q" p
;; false for a non-intersection patches.' H/ w% [: G, N
my-row ;; the row of the intersection counting from the upper left corner of the
, l5 I$ D, f5 `. ` ;; world. -1 for non-intersection patches.
t3 i2 _& c9 Y: n my-column ;; the column of the intersection counting from the upper left corner of the0 a% W4 K# L6 n0 |* w Q9 z
;; world. -1 for non-intersection patches.1 R" P- T$ r# r; a
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
# K/ [6 M/ E g0 ?5 T9 N4 C" B7 O auto? ;; whether or not this intersection will switch automatically., z: P" L- c3 ?2 s& D( |
;; false for non-intersection patches.2 ?/ ]6 S: ~, f f9 V( D: m
]
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2 q( |/ E) }2 b+ q! ]' Q3 \;;;;;;;;;;;;;;;;;;;;;;) Z. P4 t: [$ @% u4 x- ~( z' c* L5 q
;; Setup Procedures ;;
6 G4 y( l3 P( b' ]/ T; Q;;;;;;;;;;;;;;;;;;;;;;: A: y. Y8 k5 \! T0 M! y
6 U: ?, ], Z0 @. X" c;; Initialize the display by giving the global and patch variables initial values.
) _: ^, ^- _; g" w* _' c5 S;; Create num-cars of turtles if there are enough road patches for one turtle to
1 |- R% h/ F6 a. {, b;; be created per road patch. Set up the plots.
' T9 B* X. j$ k6 rto setup; Y( l- o2 z2 T1 Q9 e. X+ r
ca
2 r {$ ]7 {3 O {7 { setup-globals
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! A5 s1 a* \) S9 Y ;; First we ask the patches to draw themselves and set up a few variables( g! _. K& p9 q) j
setup-patches
" B0 A; A( c$ R+ m$ I make-current one-of intersections* ^1 j, K6 S0 d& x' q, `
label-current
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5 i& `8 Y' ?' K) J2 h set-default-shape turtles "car") R2 u/ ?- a: q, q) M, d& U1 ~2 A
: T) f5 `* ^ Y# `( l. f' h if (num-cars > count roads)4 c/ t9 [6 `( d; Z/ I- z
[
: C0 x0 w0 X* i user-message (word "There are too many cars for the amount of "
. a _; H( o f" [8 e% H! s "road. Either increase the amount of roads "
* j' |! Y) S/ { "by increasing the GRID-SIZE-X or " `" u' W/ S- \# Q; r
"GRID-SIZE-Y sliders, or decrease the "
% r0 ]' S6 j* a& U "number of cars by lowering the NUMBER slider.\n"
! J# V' t* V; Z "The setup has stopped.")
$ q1 D- P! n! ^# D. B. X stop' B; F8 T0 ]) O" v/ Z% L5 t
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- J/ e0 s" q! z: Q9 Y, t+ a% v5 _ ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color& e: F1 `* y% J9 A0 _1 {
crt num-cars
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: T: I1 r6 }1 l j8 L setup-cars
% i3 W3 k0 O8 d7 o! X P4 M set-car-color" J! M/ @9 F; q. ?, ?( |7 ]' {
record-data
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3 I( g# w9 P8 L2 F ;; give the turtles an initial speed: x) w$ c& c f' Q3 d6 ~
ask turtles [ set-car-speed ]" y, |+ z8 [5 j2 f$ F# `2 z
5 a, w+ z$ B. ^5 V$ |' G7 k b reset-ticks" T8 T7 M/ w4 S$ h; B/ K Z$ Q
end9 o' j' R. P( E3 y
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;; Initialize the global variables to appropriate values
2 B, Y( G+ p0 G9 M: p9 M! ?to setup-globals" p4 _/ i; H6 j0 \2 P6 V
set current-light nobody ;; just for now, since there are no lights yet* y- A. p& N( d) I7 v4 }3 ?
set phase 0, X% o6 T `$ C
set num-cars-stopped 0
* J* T0 H' U, e set grid-x-inc world-width / grid-size-x
' W6 R# S) l. d( Z; b% r0 n set grid-y-inc world-height / grid-size-y
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) |. I* z# a- a' l5 ]+ E ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary/ B' V2 V: x& V; t, G
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,* l: [, W. Z/ ?& X& H' R) D4 R3 w
;; and initialize the traffic lights to one setting
$ M* I- \* Q0 d2 |$ ito setup-patches3 T4 o$ |9 S F- K& ^" f
;; initialize the patch-owned variables and color the patches to a base-color8 h8 \& k/ S3 I4 T: t" I4 j
ask patches
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set intersection? false
0 h+ p) A' [7 f1 n: y: G% O5 @8 O set auto? false3 |$ w R- Z3 \3 e; B. h9 v
set green-light-up? true4 j. k+ C# F! X2 H' f6 l$ \
set my-row -1
6 N8 I, \- J6 a' r6 h, c set my-column -1; {4 G o4 B% l* M: P& \% W$ s+ f; n
set my-phase -15 y$ [% r# V3 @: @
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets# u: E$ \* s* l/ W
set roads patches with
O; T" B L6 T$ |# \* U [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 @8 `& q) _0 _6 ^) i (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
8 Z: P7 ]" p+ ^ ] set intersections roads with2 ?! U0 o1 y1 n/ F) U) S$ s3 E
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
) j: }# |0 U/ s: D- u (floor((pycor + max-pycor) mod grid-y-inc) = 0)]& L6 u- ]) r$ O- o% |
6 u2 @! y- x4 [' Z5 a. ?4 d ask roads [ set pcolor white ]& v4 a8 Y' m: `6 k% o
setup-intersections0 N, E( b0 N, B4 o# u
end
. C0 c) T- C' W/ n8 m$ k. b其中定义道路的句子,如下所示,是什么意思啊?
5 }' Z6 x+ u/ Z2 ^. H% D set roads patches with) q8 \% x# ?& G4 i+ E
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 U+ F7 d4 p, s2 J) L (floor((pycor + max-pycor) mod grid-y-inc) = 0)]' U& S. T& d, _. f W2 j# o
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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