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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。; z5 F5 _# m4 V% d, y
netlogo自带的social science--traffic grid这一例子当中,
' t6 {7 k. S* Pglobals
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) u" a) H- ^5 ^$ N: M grid-x-inc ;; the amount of patches in between two roads in the x direction( E; G5 y) l1 E% c
grid-y-inc ;; the amount of patches in between two roads in the y direction
- j% y- Y" }3 Z( A, B" ?# r acceleration ;; the constant that controls how much a car speeds up or slows down by if
! B2 O! r( K, v* C) l ;; it is to accelerate or decelerate
- j- T' F Z! b phase ;; keeps track of the phase7 z2 ?% F Z6 V W
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
* y, h" s' V" I% V current-light ;; the currently selected light l" Y: k. M* {9 `+ e* F% \% q% @
" Q! U9 u/ D! n) V# O, i ;; patch agentsets
r+ G; p) S! a intersections ;; agentset containing the patches that are intersections6 U& w% l5 V8 f: c2 B) O
roads ;; agentset containing the patches that are roads
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turtles-own9 u" V' B2 A% s
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speed ;; the speed of the turtle
( s+ \% @' S, Q8 ]" B4 c up-car? ;; true if the turtle moves downwards and false if it moves to the right
7 C5 F/ c5 x0 c+ L wait-time ;; the amount of time since the last time a turtle has moved
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; }! ~' e: n: B% V* z5 [2 j2 tpatches-own8 ]; I) F) S6 T/ Y! Q/ h) `; v
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@. y1 U& x- q2 S7 [ intersection? ;; true if the patch is at the intersection of two roads0 {, V: |! U0 `5 I
green-light-up? ;; true if the green light is above the intersection. otherwise, false.: S* } r/ p2 R* i
;; false for a non-intersection patches.
+ o% G1 A% ^' q+ K" r# R, I my-row ;; the row of the intersection counting from the upper left corner of the
& H/ B1 L f. C) M ;; world. -1 for non-intersection patches.
- }5 p7 P1 g5 W2 Q- M) o) B! f my-column ;; the column of the intersection counting from the upper left corner of the* |' u! A$ P' I5 C7 t
;; world. -1 for non-intersection patches.$ ?$ _& }4 c e: b8 ?
my-phase ;; the phase for the intersection. -1 for non-intersection patches.' }% }8 @' R" b
auto? ;; whether or not this intersection will switch automatically.
& c3 k) w8 G$ v+ |8 p c7 x ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;$ |$ w t/ \% y2 r' I5 q
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.5 b, t- ?0 G5 Q9 X/ E+ S( y# }& ?
;; Create num-cars of turtles if there are enough road patches for one turtle to
/ y6 o: U C& Q T6 S9 h;; be created per road patch. Set up the plots.
1 ?# y: C6 m. v" O% pto setup
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% F: H9 X4 @ s g3 L/ t setup-globals" F, g- U8 e# i0 W; w' d
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;; First we ask the patches to draw themselves and set up a few variables
+ O& f- R# C [2 w8 {; b setup-patches
# i! B( T" m }# w make-current one-of intersections
8 h4 K9 T5 T- m$ z. K. {+ g* ?6 ? label-current6 z$ Z6 o2 g* I( i2 }0 p, m
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set-default-shape turtles "car". ^9 U/ Y# O8 G# Y3 f
& |9 M+ Z0 p, ?7 I7 M3 w: ] if (num-cars > count roads)
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2 f% u) O R- d: q1 |/ p user-message (word "There are too many cars for the amount of "1 @' O$ U( h+ ^ e
"road. Either increase the amount of roads "3 j- i' `& j% u+ o9 J
"by increasing the GRID-SIZE-X or "2 k& Q B0 |1 i6 R
"GRID-SIZE-Y sliders, or decrease the "* [" ]0 R) [2 ^/ k4 H
"number of cars by lowering the NUMBER slider.\n"9 M$ L V( z6 J: o
"The setup has stopped.")- p/ s* ~/ Q$ n
stop; B+ R( Y& _- t; D$ j& e6 Y% V D" O
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4 T# O! W+ ~1 B3 ^. O! C* d ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
, ~6 \) {% n. i4 [6 c' @' ] crt num-cars+ i9 m$ r2 t0 z4 q
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setup-cars: o! G$ h! Y" q6 D" [
set-car-color
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;; give the turtles an initial speed$ s+ }; r# N7 {! f, ?2 n
ask turtles [ set-car-speed ]
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! ]# i1 R" P& K! ^& \ reset-ticks
. v: {% N; f4 ` k3 Oend
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;; Initialize the global variables to appropriate values+ |0 C* S, ]# U+ M! z7 D# A
to setup-globals
* ]4 ?- P& A$ f* Q) y set current-light nobody ;; just for now, since there are no lights yet7 D; w: R' \/ b) F
set phase 03 M2 Q! y5 I, z) s' ]' @/ V! A
set num-cars-stopped 0
- z' R* w0 j8 U$ U, X9 S8 N) T set grid-x-inc world-width / grid-size-x
7 J0 t6 @% u5 K8 q1 o. K set grid-y-inc world-height / grid-size-y! K. J- J2 t6 ~ k! \
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary1 q& _% k5 t S# o$ B! R: P
set acceleration 0.099
! }0 G* t4 k4 S) l( y1 |% X/ }end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,$ A5 d* Y+ t: P1 Q
;; and initialize the traffic lights to one setting
7 b9 n' {" m# cto setup-patches6 J9 a. }5 ]6 K! F6 p: Z; @
;; initialize the patch-owned variables and color the patches to a base-color' V J! c; c% M& D% q
ask patches0 Z$ u' q) [; k
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0 f% h/ d1 S7 w: }( z- j set intersection? false
* i: t: Z* ]2 k) E set auto? false
j$ l' ?' [ P$ ^9 A$ q& e9 y. `8 U set green-light-up? true
2 n- I; W2 ~2 L+ r set my-row -15 G# L* O! x+ p& c9 S9 \
set my-column -1
& q2 s6 ]0 n4 E/ q" I( J set my-phase -1
8 i& @7 Z. k) ?1 h& F, l set pcolor brown + 3
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8 L$ E% w% n% u! y2 w; P8 Y/ i ;; initialize the global variables that hold patch agentsets
& C" w9 `8 R# q% U set roads patches with
0 W2 T1 |# i! N( c: B; R; W [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" x4 i- s7 X" z( y0 f
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]" U( C" Z1 \2 K: G7 I
set intersections roads with
& U# a; P+ f L( O1 i- B; A4 @6 U2 E" W [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and) Z: y5 `! r# V
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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7 B% a6 K' I2 G: u( r! @ ask roads [ set pcolor white ]! C( v" |1 x1 L. z7 |
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?
1 w C! A; n: p5 }- I6 X set roads patches with! F; f+ }3 ^$ A1 g& c9 s8 |; J& {, t
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
( V7 @# N8 ^* b& S$ {. |9 \ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 G9 c5 y0 [: o; 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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