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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。
8 f6 N0 T) f. ^- O/ d2 Anetlogo自带的social science--traffic grid这一例子当中,
! u0 K4 A' n$ J, h( Lglobals ?0 K& h8 n! t) G' v
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grid-x-inc ;; the amount of patches in between two roads in the x direction
" C9 W5 N t& a- d1 t grid-y-inc ;; the amount of patches in between two roads in the y direction
# G+ E! T+ i3 ?! }" s) j- y, l acceleration ;; the constant that controls how much a car speeds up or slows down by if
7 Z* u5 _# P1 y. T) ?: c2 {- B ;; it is to accelerate or decelerate
9 a7 z9 I- {) l3 c, I" l phase ;; keeps track of the phase
4 N3 {8 D( Y8 N! N num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
$ r: `1 P0 o6 ?! t) O) _ current-light ;; the currently selected light
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;; patch agentsets
0 H" P: e1 j9 ~* i% t4 o intersections ;; agentset containing the patches that are intersections
& `7 K6 J/ t) @- m0 B& m roads ;; agentset containing the patches that are roads1 D/ X$ R4 Z& e
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" I2 d. V. X( J3 U- c8 Vturtles-own/ I8 M1 H' p% s( d" r! G6 I% T
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! p* j5 S/ d+ X) y( o8 R9 O speed ;; the speed of the turtle+ P' B \# Y0 R; V# b1 Z8 S: Q
up-car? ;; true if the turtle moves downwards and false if it moves to the right( |' @& S, `! D- a( d4 C* N& b
wait-time ;; the amount of time since the last time a turtle has moved( x5 {+ w9 G- T6 l' x4 {' H! a
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# h& f3 L" ?+ v5 M4 i' M L. o& lpatches-own
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0 x( e: ?. p# u intersection? ;; true if the patch is at the intersection of two roads
/ U9 `$ m2 E. s9 [6 | green-light-up? ;; true if the green light is above the intersection. otherwise, false.
) Y0 {. p. ^- o E ;; false for a non-intersection patches.7 V( _* @' c, |
my-row ;; the row of the intersection counting from the upper left corner of the
! s! e1 v0 L0 k+ V- g ;; world. -1 for non-intersection patches.. K* X2 E u' o* G% M8 q" H/ a
my-column ;; the column of the intersection counting from the upper left corner of the
/ L+ R7 _3 W E! t/ N ;; world. -1 for non-intersection patches./ u& A3 l1 s# ~! v" D7 b! P9 |
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
3 O7 H3 C0 S* D9 q+ t# \ auto? ;; whether or not this intersection will switch automatically.
7 ]$ F l9 K/ \% a ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;, ` c% {0 x0 a
;; Setup Procedures ;;4 |# P$ a! Y0 ]* h3 V
;;;;;;;;;;;;;;;;;;;;;;; E) H; W) S9 \. s% e) G+ V6 k
+ J, G ?5 K5 Y4 A' }
;; Initialize the display by giving the global and patch variables initial values.7 r+ Y- Y1 H& E1 _& {* L
;; Create num-cars of turtles if there are enough road patches for one turtle to4 |# k) k1 z9 [" L9 h
;; be created per road patch. Set up the plots.. N {$ _* x$ L. d2 x# z2 E
to setup
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setup-globals
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7 H. q$ U6 N/ s& `- Y& O ;; First we ask the patches to draw themselves and set up a few variables
8 B! C" M( |3 E8 K: f% a4 P$ N q setup-patches
; T3 y) J. O5 u) \: S* [% m1 ] make-current one-of intersections
2 X1 K% B F, |$ {8 C* I label-current. S% R g* M. A/ a* l% s
+ R* n C4 |( t: V2 C6 K- S set-default-shape turtles "car"
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if (num-cars > count roads): r8 v5 m% d5 j5 f
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user-message (word "There are too many cars for the amount of "% a" Z; E; l! A1 U0 Q+ a& K d2 Z
"road. Either increase the amount of roads "5 C+ N% K" l1 v1 v2 V1 T
"by increasing the GRID-SIZE-X or ", x0 H% U3 s' F$ E! }! Q
"GRID-SIZE-Y sliders, or decrease the "
e) A/ @8 ~9 g6 @ "number of cars by lowering the NUMBER slider.\n"
) j( U7 d5 U- D C "The setup has stopped.")# @0 y4 O- o2 n; G' g
stop- \1 A' C$ ^; U
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color/ A; {9 y$ \% }4 T0 S' R) A* N
crt num-cars7 X5 a. G; c" _% q! z$ _" }- d3 ^
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9 k: d1 w7 F t1 z: d& D setup-cars: R. |5 d7 e4 A( T) P/ x( y
set-car-color
9 j! ?2 m+ y5 t W7 C$ Y" J record-data
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;; give the turtles an initial speed' U5 {) j0 ^+ l1 `' I
ask turtles [ set-car-speed ] G. G: F( H4 Q5 K
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reset-ticks+ _" Y4 D2 \2 H
end1 p9 v! p) Z" Y5 s, Y6 H
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;; Initialize the global variables to appropriate values
. A1 e0 N) k; v% Uto setup-globals4 w( N+ p! f" z0 Q% P
set current-light nobody ;; just for now, since there are no lights yet; }( D. O# U/ [8 o# }% s/ X5 y
set phase 06 B! A# z. [1 s2 x
set num-cars-stopped 0
$ |( ]% |( S% r, R* H1 ~8 B set grid-x-inc world-width / grid-size-x! j& e! r# i C7 ^, G6 d+ S. B
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/ I0 X3 ^: t0 c1 Z
set acceleration 0.099
1 X @. ]. _* Eend
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# X& e6 W/ i. P# C F+ U' \;; Make the patches have appropriate colors, set up the roads and intersections agentsets,9 _* x2 D$ w/ I( g4 H7 m
;; and initialize the traffic lights to one setting! j: @. I0 p' ~: F( J
to setup-patches
+ a; Y! r3 U( T) G) s* g ;; initialize the patch-owned variables and color the patches to a base-color% s) Q! ~# ]" p0 C) r
ask patches
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set intersection? false
" m9 ?3 T8 v# Y. Q set auto? false
) q% d: t3 ]& o/ V3 w& ]" A set green-light-up? true
" I1 k, v4 y' E+ o5 t set my-row -11 a! T& Q' \* u) a8 c5 V' {
set my-column -1
% U) n* V# s, w# @' k set my-phase -10 \6 D( U. s) J8 _' v
set pcolor brown + 3
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5 p2 Q2 F! S: {2 n ;; initialize the global variables that hold patch agentsets
' P7 S& o8 B% n$ U set roads patches with3 V) A7 S1 r6 M" a/ S( A
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' @7 r3 D6 d$ Z" E
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 @4 a; r$ Y( ^) e: C: Z
set intersections roads with, |& j. U7 h F4 |
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
0 |- j+ G4 {4 @2 }6 i- A' \ _ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]4 o7 m) _$ F0 y O9 h2 \+ G
, ?: k# m& {" N ask roads [ set pcolor white ]+ ?& p& |1 j! S6 E4 b$ f
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?3 Y. F" q" g' b% P0 e
set roads patches with+ G" H; b6 x9 y u. j
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
* _+ S4 s# c4 j/ y (floor((pycor + max-pycor) mod grid-y-inc) = 0)], s: h* _0 x/ B5 Y8 t 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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