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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。
0 Z' S5 S# Q9 Dnetlogo自带的social science--traffic grid这一例子当中,
' ?2 }0 [, `! gglobals3 h0 c+ J7 f9 H) e
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grid-x-inc ;; the amount of patches in between two roads in the x direction# R( r) Z- q7 ~& M
grid-y-inc ;; the amount of patches in between two roads in the y direction' U* g6 ~5 q ^" ]4 b* ?
acceleration ;; the constant that controls how much a car speeds up or slows down by if" \; B {, [" Z/ T2 [0 T8 A8 |# p
;; it is to accelerate or decelerate- ~) W2 R& d, l
phase ;; keeps track of the phase
) N2 m- e2 x2 n9 n; l: A9 I% p num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
* V D! M- Y; k current-light ;; the currently selected light* Q/ h6 C0 d' {, Y3 J, a
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;; patch agentsets
9 o$ t$ C: {. m/ z6 V intersections ;; agentset containing the patches that are intersections @% L0 v' D A
roads ;; agentset containing the patches that are roads
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turtles-own
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- [1 _7 D: N1 ?: z! P speed ;; the speed of the turtle
0 Z! }; d) b3 o4 f up-car? ;; true if the turtle moves downwards and false if it moves to the right0 J6 p. p# ?5 v0 t* @. h
wait-time ;; the amount of time since the last time a turtle has moved, v; }6 q [. X. Y% k3 {6 s P
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: e9 H& A1 e: Zpatches-own: c7 W% d8 V, y, G
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intersection? ;; true if the patch is at the intersection of two roads
0 v; [. K4 i% h) z4 g1 q green-light-up? ;; true if the green light is above the intersection. otherwise, false.
: t$ q, [/ A) @% H ;; false for a non-intersection patches.
$ l l' B3 }- `& h1 f. z my-row ;; the row of the intersection counting from the upper left corner of the
* j! W) k" d6 H' I ;; world. -1 for non-intersection patches.
0 M& A% W+ s' Z+ A- F5 A# w9 l- w( h my-column ;; the column of the intersection counting from the upper left corner of the/ A4 i, @/ u: e. I& f/ }5 Q$ w
;; world. -1 for non-intersection patches.. q# F" d$ d& v" `: W, C5 o: k
my-phase ;; the phase for the intersection. -1 for non-intersection patches.0 O" o3 @) `$ ^; g9 L
auto? ;; whether or not this intersection will switch automatically.3 ?% M8 o7 r+ A, q
;; false for non-intersection patches.
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+ {; Z' p$ ?# K5 @! |, p;;;;;;;;;;;;;;;;;;;;;;
, o3 e, d; ~5 };; Setup Procedures ;;
6 q" e* @7 W9 S( o8 Q+ _;;;;;;;;;;;;;;;;;;;;;;! a% M1 R3 E5 o3 W
7 ~0 H1 G; [5 s; \8 };; Initialize the display by giving the global and patch variables initial values.
" N' b6 b3 h$ D. G$ \;; Create num-cars of turtles if there are enough road patches for one turtle to$ w Y$ Y) [) Y1 [0 y
;; be created per road patch. Set up the plots.
* o9 H/ z% t4 U: ^( l; C. Mto setup. ^1 U- N$ X+ o U' O
ca
' j+ T3 P. U5 P5 X8 w setup-globals
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2 W5 e( ~2 I: C3 r5 W ;; First we ask the patches to draw themselves and set up a few variables* x0 T* B5 T1 z3 z/ f& {0 |5 ?7 O
setup-patches
1 t! V! n% T6 Q$ Z/ n2 z make-current one-of intersections
2 t" ~/ x% W R: ]* a2 S label-current1 H2 [% V* r+ ]3 h
+ `1 c. I( l' C9 O1 c* U: d set-default-shape turtles "car"
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if (num-cars > count roads)
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4 M- U4 \8 J& B0 c5 b user-message (word "There are too many cars for the amount of "
- `9 @$ H# n: A9 Q# p0 G% x "road. Either increase the amount of roads "% j, U" ^* ]" K" \ W! k* y7 B, g
"by increasing the GRID-SIZE-X or "
+ Z2 G( _! [% f( g' X "GRID-SIZE-Y sliders, or decrease the ": A- j2 E1 x4 I) G- _0 F0 ^
"number of cars by lowering the NUMBER slider.\n"+ K7 m8 k0 W- f4 Q* ~, N
"The setup has stopped.")5 O2 v6 O) p6 q- |( Y
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color% c. q" N+ K; K5 T! Y- _8 Q0 _- |
crt num-cars r7 |: c# g- e' S; g* i
[
: C' w V3 R! T, L; n! R+ a setup-cars. Q' E2 V; X3 f2 ]0 G7 ?% Z" i
set-car-color
9 m- U6 a) Z( P$ ~ record-data
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;; give the turtles an initial speed& A5 J- c" \( s$ j. k6 t3 u
ask turtles [ set-car-speed ]3 P7 S$ P6 q# x" W* q2 Q
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reset-ticks0 K$ y" I* m! C- p9 c4 ?$ D
end
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;; Initialize the global variables to appropriate values
) A5 z7 \8 g& c; \to setup-globals: o/ ~: X* B9 `9 w: F
set current-light nobody ;; just for now, since there are no lights yet
1 S, j/ D* B7 h! h& m4 I; J0 f set phase 0
/ W2 z& b4 U0 N set num-cars-stopped 0
% z0 F# a1 @6 l set grid-x-inc world-width / grid-size-x
; Q% S Q2 Z, a0 A set grid-y-inc world-height / grid-size-y
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: `9 Y0 o d& D+ y6 Z ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary2 {2 f4 ]4 s! w; r8 o
set acceleration 0.0997 _3 e; ^3 _5 t; i
end9 w0 Z' ~6 E4 w4 j+ ?
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
$ f4 A9 u+ n2 k, c) n2 |;; and initialize the traffic lights to one setting! g" ~$ H. i; n3 o- w
to setup-patches
7 F( u& b1 Z; Q1 P+ z" Z% H$ q ;; initialize the patch-owned variables and color the patches to a base-color
0 [, e5 x( c3 ] ask patches
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set intersection? false0 E( `( ^% Y% `* o: a
set auto? false
; a% ^& p1 ]1 j+ \" `% J4 u set green-light-up? true5 C( b: x# G7 Z+ ~, k0 y
set my-row -1! |- i" j& \7 e j
set my-column -1
3 F6 ?' ]3 p8 |. V8 x# J set my-phase -1* R# g+ K& H3 |; ~9 a" }, b
set pcolor brown + 3
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3 |* t3 A3 \6 L$ w ;; initialize the global variables that hold patch agentsets
8 q+ Z1 Y: R. H0 G; ?9 V4 ~" c' A set roads patches with: f. ^( j& p( v- d7 F% b, W
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
* j1 e. s* q! C4 Z6 _+ M) W (floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ K6 X* [8 F8 q- @
set intersections roads with/ K W* ]& j: `2 m. H
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and. e' H7 N. W/ F# g* z( }
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 P% Z' T# w* `. T. z: g
; J: B7 e/ t1 y- c) V0 N0 k ask roads [ set pcolor white ]* u# v. V6 a( @
setup-intersections: G# [' H8 h, V% c5 T
end" b8 m2 q l) ]# T
其中定义道路的句子,如下所示,是什么意思啊?2 b) P- C7 l8 N. {# I$ z
set roads patches with6 Y9 n L( D! x) R# v* a8 p
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
0 u' Z% R2 p$ V8 V; H, W9 X (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
8 `' [" ~: N4 u/ F( `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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