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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 k' Q. N% h; a }netlogo自带的social science--traffic grid这一例子当中,
6 R: V( @: T5 I% p5 w7 S/ B. x6 Mglobals2 G0 {: ?9 {& K! ]
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! C% L X ^: M7 J+ p$ A grid-x-inc ;; the amount of patches in between two roads in the x direction
; V3 v5 S7 \' k4 g2 A grid-y-inc ;; the amount of patches in between two roads in the y direction
" D4 L R6 l6 P+ _6 m9 L acceleration ;; the constant that controls how much a car speeds up or slows down by if+ w5 n1 h, U' i' E" d
;; it is to accelerate or decelerate b! q. c2 e. I. r3 b
phase ;; keeps track of the phase
& A/ p% O$ H9 s num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
4 A2 z6 T/ H! D# E V current-light ;; the currently selected light+ u+ A0 v2 A# K. m1 Q9 l
0 p/ d+ }5 ?+ b6 s, D5 ?
;; patch agentsets
- G7 W L, D; M/ T/ `" Z intersections ;; agentset containing the patches that are intersections6 a6 R1 M- {4 ?2 x4 z- G
roads ;; agentset containing the patches that are roads
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turtles-own2 }8 v9 w( s. l9 }
[2 a* \1 G a$ B
speed ;; the speed of the turtle
" |& {7 T4 H) I# F; a. y up-car? ;; true if the turtle moves downwards and false if it moves to the right
% F) U9 B5 U6 G! M# D% v: E wait-time ;; the amount of time since the last time a turtle has moved
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2 i: c% C; y9 {; n* M9 D$ Ppatches-own8 Y, a+ V- k. u/ z. r
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intersection? ;; true if the patch is at the intersection of two roads" a, n! J/ d/ p) {! _ b2 m
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
: d9 B* X3 |" ?, s X. z N% P ;; false for a non-intersection patches.
1 @0 D- D, K1 y+ a7 n2 W my-row ;; the row of the intersection counting from the upper left corner of the9 y% ^0 u2 J$ Y, C
;; world. -1 for non-intersection patches.: {* {: n) Q2 \5 m; _: x# z% ~
my-column ;; the column of the intersection counting from the upper left corner of the
3 \8 \) W8 h5 Y* n ;; world. -1 for non-intersection patches.- O; ]8 j3 [' K& Q, e
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
2 Y! |4 \) k/ p$ S, k+ h auto? ;; whether or not this intersection will switch automatically.
- ?/ ~8 A, j) s* ?9 ~$ j% a ;; false for non-intersection patches.! b* j! L5 Q9 a n9 p2 X& Y
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;;;;;;;;;;;;;;;;;;;;;;9 p" t# W/ e: W. \# G
;; Setup Procedures ;;
$ W! ~% M# L& w; r( E: x/ k4 n: e$ t;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
% @ |& z+ H+ e, r' Z; N+ _;; Create num-cars of turtles if there are enough road patches for one turtle to6 z) {, @$ g: U4 z0 F9 |0 M' u
;; be created per road patch. Set up the plots.8 I7 B+ \7 [: t7 M1 o( O
to setup" \5 ~+ E( A& y
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setup-globals. K, d* c( r9 j5 ^" U
9 r( i$ l" w' |( _ ;; First we ask the patches to draw themselves and set up a few variables0 ?' F% `$ N4 s! v6 ]# L4 D
setup-patches
1 j6 w4 n) z. v make-current one-of intersections; J6 |* s" x, ^. O ~
label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "1 ?6 p. m) p: Y
"road. Either increase the amount of roads "6 e% N5 L: o. v# Z, K7 }3 }
"by increasing the GRID-SIZE-X or "
& i. l* c2 g s6 N1 N "GRID-SIZE-Y sliders, or decrease the "
& u; ?' V& h( I' R. ~- d; j- m6 t7 |0 e "number of cars by lowering the NUMBER slider.\n"# ^# l* G @! ~2 t9 F! i
"The setup has stopped.")
& r' U" H- i/ j8 w9 | stop
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( h, i; J1 o/ q- K: h ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
3 Z0 F1 m5 ~/ a( A1 ~0 _* G; q4 b crt num-cars
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2 x l6 L. m) y setup-cars
: e# X3 M/ S# |3 N% `5 b/ N) v* B1 r( P set-car-color8 E6 ?8 _) E; ?7 x2 @
record-data
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: O9 X% H* A4 z _1 U, D ;; give the turtles an initial speed
+ G; Z: _6 D& u# U ask turtles [ set-car-speed ]
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reset-ticks: `9 b# X. l2 i
end" M5 M0 G% \, X! d- I
- d, {' V( G/ d1 ]! ]& y* n;; Initialize the global variables to appropriate values. ~1 h/ g3 i7 Z7 K9 o
to setup-globals
$ Y+ O' I. g0 d4 [ set current-light nobody ;; just for now, since there are no lights yet
4 v6 [9 V" i" ^' m. k" p set phase 0
7 d. W- U% A* T9 N, W set num-cars-stopped 0
6 I( l% i# \! g set grid-x-inc world-width / grid-size-x5 c6 x9 A6 ^" x) m0 Q7 D k
set grid-y-inc world-height / grid-size-y/ K+ X! g' E( I" m; ]5 n7 Z
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
. o+ i! {1 P- a2 O set acceleration 0.099
* v! {8 r3 b6 k( W: _end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
" h V# i1 n8 G0 D- \( H;; and initialize the traffic lights to one setting
( o" F2 _# D( ^: fto setup-patches" d+ U+ L7 [+ ]8 Y/ D o( k
;; initialize the patch-owned variables and color the patches to a base-color
) T7 p' F( {4 Y# J9 d) B. l5 Z( k ask patches1 o* ^0 r: J+ G
[
8 u$ A7 {0 b: g+ `$ \/ _- N set intersection? false
; `# O, a7 I; x) ]: } set auto? false5 Z+ m' {1 X, L4 L& A) V3 I
set green-light-up? true/ w) f3 O6 P# R$ l+ X' ]& X
set my-row -10 f; u% z7 A5 r7 H; _
set my-column -1
1 ^& y( |) _* |$ ^2 ~0 j: }- k. T set my-phase -16 c; Q# J/ ^7 I: A7 ^0 D7 U- w
set pcolor brown + 3+ Y+ x$ H4 H3 b; d
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;; initialize the global variables that hold patch agentsets
2 h* G! N1 T8 c set roads patches with. o, }" s+ D3 p% q
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or$ {: A8 m; g: b# c- _2 W; C9 o7 T
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 C+ T* F& e# i0 f. m set intersections roads with
* a1 ^) ~' s" j/ P' A1 a [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and8 C; V. B( j& W2 N
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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5 t+ }6 W- q! [' Q$ A8 r; t ask roads [ set pcolor white ]
. {; H0 J+ Z) P6 w# X0 c% O- F setup-intersections
* U3 [, q N1 d/ `end
( a- l! {# X& T1 F7 o其中定义道路的句子,如下所示,是什么意思啊?
9 N6 O0 J, `# W/ {& e set roads patches with
* b8 ^/ B; ?& h: l1 m+ ] D7 C: h8 D [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" @ x+ z( [$ A8 C" `: {# Z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 P( _/ Y+ x# j4 e
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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