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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。# z! }& s, ^; \* b6 ]
netlogo自带的social science--traffic grid这一例子当中,
! R! o% q$ r) o+ O1 n% iglobals7 t* t2 e0 Y& ^' o) l6 Y5 D
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/ ^9 p, u& s8 |* ^3 R grid-x-inc ;; the amount of patches in between two roads in the x direction3 o! f# _: I* \+ z% W2 D& G+ P
grid-y-inc ;; the amount of patches in between two roads in the y direction
/ A: F' u: _! w5 Q8 n9 w& { acceleration ;; the constant that controls how much a car speeds up or slows down by if
* @: L$ P* H5 H3 N8 y. e ;; it is to accelerate or decelerate
/ {* t9 J- {, @/ b0 n8 @ phase ;; keeps track of the phase8 y4 U6 h) O+ x% E
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
5 y9 w8 n/ X( |! \* F5 n# |! L current-light ;; the currently selected light9 Y6 v- Q* d, `1 \3 \
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;; patch agentsets
3 b3 |" V! M3 g8 i intersections ;; agentset containing the patches that are intersections
! t6 U$ p# U& |8 v2 R; [ roads ;; agentset containing the patches that are roads
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turtles-own! h2 z. i( Q/ Z b5 o6 e
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speed ;; the speed of the turtle& ?5 O5 N& t* l2 S
up-car? ;; true if the turtle moves downwards and false if it moves to the right) `8 P# h2 G7 @: E# b! k% x
wait-time ;; the amount of time since the last time a turtle has moved
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6 r- _: P M$ K1 Xpatches-own0 W( `* `* [. r4 h
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! ]2 `& K4 M- t3 {/ _ intersection? ;; true if the patch is at the intersection of two roads" w4 o8 M1 e3 o7 J5 P! S7 _
green-light-up? ;; true if the green light is above the intersection. otherwise, false.4 L0 _1 J1 c0 X. y9 m
;; false for a non-intersection patches.
: D# [7 h9 }% i; { my-row ;; the row of the intersection counting from the upper left corner of the
0 m- W! R" A9 A0 |" y% i4 W ;; world. -1 for non-intersection patches.$ d/ q k; a* E* F0 ?
my-column ;; the column of the intersection counting from the upper left corner of the& Q8 k9 R' L6 h% b# w
;; world. -1 for non-intersection patches." _- g5 r0 V6 a* H$ w+ \( _
my-phase ;; the phase for the intersection. -1 for non-intersection patches.# L' h- t, j# }4 N/ B
auto? ;; whether or not this intersection will switch automatically.3 e0 I& [" E0 B$ l6 E
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;5 |0 U0 |+ Y. N5 a
;; Setup Procedures ;;
& H: T4 |5 z: {7 x( R;;;;;;;;;;;;;;;;;;;;;;0 h3 z$ }) y. f& l: d- f8 m
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;; Initialize the display by giving the global and patch variables initial values.
" d- h% ~4 X1 p) a;; Create num-cars of turtles if there are enough road patches for one turtle to
$ O" d; r0 ~2 r;; be created per road patch. Set up the plots.# g; d! Q+ a/ v: r* t. b8 T1 s
to setup. h4 m( b5 S! m9 e0 p
ca0 C3 n. `' ~) B* d" _
setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
3 e5 j* |- M4 p8 E$ n+ F setup-patches
W! K3 ~3 y; p& | make-current one-of intersections
: w; s1 x2 V# W: x label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)) s! \+ L- n% d' K+ z$ R: @0 T2 R
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1 S4 A: u: ]- }3 W* g user-message (word "There are too many cars for the amount of "
( X7 o+ w/ ]6 r( f# k "road. Either increase the amount of roads "
( p0 m: i7 L. e7 U8 t$ u& i( s k9 ^ "by increasing the GRID-SIZE-X or "
/ _" Y- d! F6 N& ]8 _ "GRID-SIZE-Y sliders, or decrease the "
0 L3 f, q- a6 \; R "number of cars by lowering the NUMBER slider.\n"
7 q' S' s3 {$ _: C! m5 f/ x* [ "The setup has stopped.")
! T6 \' |+ {0 @ stop
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/ ]9 u! l3 q' M2 e& {! L- x: ?/ X ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color( p3 R5 w/ k$ f
crt num-cars. s1 a" i7 O# G0 d2 g- w4 V
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1 X7 k0 W% \4 c' S: A. m8 h5 F setup-cars
$ h3 f3 o }& \( x set-car-color
U( s: R, U9 Z! _ record-data
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0 k7 d$ S9 t" k+ |# S3 ]# M$ t ;; give the turtles an initial speed. t4 }& K& h% { U" S7 i
ask turtles [ set-car-speed ]1 X$ J, ~' O5 D" j6 n9 p2 K! \. T
$ O. _! `$ t3 H! B4 k reset-ticks. _, D( g8 V& h0 ~8 w w( S
end9 V) J& B1 T) t4 o0 s& R
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;; Initialize the global variables to appropriate values! w: @8 a! r. Y2 U
to setup-globals
: T! O& N# q. ]4 B* N5 } set current-light nobody ;; just for now, since there are no lights yet4 Y5 J' p0 K8 N7 W' x
set phase 0
9 ]( X$ x, B- i, H0 H set num-cars-stopped 0
& R" w7 {: k% R' F% O0 M0 B set grid-x-inc world-width / grid-size-x) _/ A5 f' I, D. }, v$ B8 i+ W7 G& w
set grid-y-inc world-height / grid-size-y# A; Q, D% a0 r9 a: V/ c4 j
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary: c7 w4 L2 Y9 W: K
set acceleration 0.099
+ a. N0 K; J8 send
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$ j* X8 p% F8 ~ y7 } z& K- q;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
7 J# G$ y2 q2 D: p" R;; and initialize the traffic lights to one setting( C: b% g% m% @4 J% y; O- S) L* F
to setup-patches: \0 S$ T6 K; [+ R. t' r
;; initialize the patch-owned variables and color the patches to a base-color$ z& H7 T: `$ m: W F
ask patches4 M. I! p# U N; B: f2 [
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set intersection? false- h$ Q- e6 w. @* e
set auto? false: r i- j0 R( _$ i( `! B; E
set green-light-up? true
7 q* I. I5 Z4 C( Y, G3 M set my-row -1) n6 `8 E( U* x- B' [- Y+ B
set my-column -1
& ?/ e) i5 I4 f. Q set my-phase -1! X# r9 \4 }2 }+ \2 [- C
set pcolor brown + 3/ K' u2 W' p$ J) u# m
]
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/ J$ F0 ?5 e s8 p* b ;; initialize the global variables that hold patch agentsets- c7 n$ z E3 y4 Z
set roads patches with3 r, ]5 L! I; _
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" H$ B4 Z* _7 \
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: N7 m( y3 b: [ set intersections roads with/ k5 n4 S! I6 R, W4 J0 Y, Z# Q- ^
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
5 [0 ?( d3 D7 k! b& q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]# I. _% w5 |- O3 y0 @; P
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ask roads [ set pcolor white ]
8 H& O& N& S& _, m$ A7 w- P4 i setup-intersections8 K$ A3 g: ~( |. B# @
end6 L7 H" u6 P! A& ` ^0 F( W
其中定义道路的句子,如下所示,是什么意思啊?$ M( ^0 Y& [: a+ ~2 P
set roads patches with5 \9 V; r! U7 f# u" B
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or& C9 ^6 Q( o% U+ I0 }
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; U& p3 d4 D2 k; \% 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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