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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。; w3 O6 Q* g/ U5 d0 p
netlogo自带的social science--traffic grid这一例子当中,
a c$ S2 A) h" e* }globals- s6 |+ c; e# s/ Y( i6 |, l/ w1 w& {
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grid-x-inc ;; the amount of patches in between two roads in the x direction* o- Z* y" Z1 i
grid-y-inc ;; the amount of patches in between two roads in the y direction
3 r. G6 p' I u$ e q! a4 U8 s# @ acceleration ;; the constant that controls how much a car speeds up or slows down by if
( t* O1 d0 ^2 y; b ;; it is to accelerate or decelerate
0 y2 p8 i" q9 g phase ;; keeps track of the phase
( r. {& Y+ [6 w/ |; R. o4 D num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
# e% A9 c* @5 i+ I; b- W% C current-light ;; the currently selected light/ r1 f/ K5 ?2 }& C0 G9 }( \4 w
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;; patch agentsets. ^; U/ T/ j5 W) y3 d0 O. O
intersections ;; agentset containing the patches that are intersections
( z, Q5 f: K1 D" E6 e roads ;; agentset containing the patches that are roads
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; u5 R! Q. D, @' j+ o5 m0 Hturtles-own" b1 i( ]4 N/ X7 R/ @
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+ k1 \+ |) v, U } speed ;; the speed of the turtle
7 i* M# g: F! R0 n0 j+ F up-car? ;; true if the turtle moves downwards and false if it moves to the right( j) a2 B \. V/ b$ K7 w& y
wait-time ;; the amount of time since the last time a turtle has moved! L" X* x4 P- ~0 p J: @5 E
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patches-own- ^7 N! x# }+ ^1 F' ~
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5 z) W6 d- k7 i5 K, j' [ intersection? ;; true if the patch is at the intersection of two roads' e1 H9 H( {* o5 T2 R4 n
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! Y6 j" E) W& }- m$ F( R+ a ;; false for a non-intersection patches.
0 k( u* t# y, c9 t7 u my-row ;; the row of the intersection counting from the upper left corner of the
: ?" s7 I; f$ ~0 R ;; world. -1 for non-intersection patches.9 |$ K7 X* M7 `) D4 i8 O
my-column ;; the column of the intersection counting from the upper left corner of the5 L3 Q, r3 I2 s! v& X
;; world. -1 for non-intersection patches.
" A- R9 z8 l% d5 U/ ` my-phase ;; the phase for the intersection. -1 for non-intersection patches.
E, O$ N4 |6 N. \: i5 h8 G0 y auto? ;; whether or not this intersection will switch automatically.7 Y5 }5 k. F6 X7 r5 b
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
5 g7 |0 L$ v$ V# H% M;; Setup Procedures ;;
" }& n$ A; ~7 ~3 B;;;;;;;;;;;;;;;;;;;;;;! z0 w' n9 U; _! h
7 _: G$ _* C( @$ z7 ~' H;; Initialize the display by giving the global and patch variables initial values.
5 ?" c w! `& ]2 @- z1 w/ X4 \;; Create num-cars of turtles if there are enough road patches for one turtle to) [% }4 T p5 X0 D/ H) u
;; be created per road patch. Set up the plots.! m. v) ^8 B* ~4 ~" d2 W1 g' f
to setup V* v. Q8 D& l9 D. y5 |
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setup-globals' ?) D8 ] b# w' P# l
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;; First we ask the patches to draw themselves and set up a few variables: g4 ~. E6 P! F5 i
setup-patches
3 z1 i/ m! Q/ y* _6 B M# t5 \ make-current one-of intersections2 k9 l" g: l8 v5 H( V; O
label-current
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set-default-shape turtles "car"
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5 ]6 l* B; o8 e+ t% ~ if (num-cars > count roads) s3 \+ @4 g; o
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user-message (word "There are too many cars for the amount of "
2 S @1 w0 m# {. p1 v "road. Either increase the amount of roads "
4 `' s& {$ f' G1 n4 d "by increasing the GRID-SIZE-X or "1 t% i' ~, ]& w, s
"GRID-SIZE-Y sliders, or decrease the "5 | Y' t& K' }! o6 g5 ?
"number of cars by lowering the NUMBER slider.\n"
5 l* L5 N4 Z, p, g( p "The setup has stopped.")
; N$ ~' R4 P. s" P9 ^8 Z% r stop
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$ P% Y, a3 Q# U1 }8 e ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
% v; |& r7 h! l crt num-cars
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setup-cars9 ]" a6 c9 K! |) F
set-car-color: }8 ~- U! _' h
record-data/ j$ V( G5 l2 i& M+ H6 i5 @
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7 Q8 i7 x1 ~6 w5 Z9 C" ]6 n" T ;; give the turtles an initial speed
# H! e! m4 N- J- j5 G7 E5 C ask turtles [ set-car-speed ]
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reset-ticks9 O9 @6 k! H$ b4 i
end2 |. B% R" y2 X4 K, S6 h) u' v
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;; Initialize the global variables to appropriate values
8 l7 R0 q0 T- m2 o1 H, Kto setup-globals
4 F# n9 z& }( T% n' u' @9 ^ set current-light nobody ;; just for now, since there are no lights yet! C! Q V" A# B0 _
set phase 0; R, n# C5 N+ `+ H' c
set num-cars-stopped 0
* {% @6 ]& y7 P7 J set grid-x-inc world-width / grid-size-x4 r3 F+ _ U9 L1 A$ v4 ^# s
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 boundary1 w& I. Q! m" w i: J0 V; A5 S l1 ]
set acceleration 0.099# M* |$ h2 z( R! ?* ?0 F5 [3 Q
end9 z- d u( Y0 H) {" y/ n
" ~) j# R$ F& t( h% z: D6 I1 Z;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
G+ C; q4 d; C* k6 u: i;; and initialize the traffic lights to one setting6 H. K& W1 b6 ^" t3 T
to setup-patches. h+ ^& ~5 }6 q' U2 H8 j
;; initialize the patch-owned variables and color the patches to a base-color( G# `/ U* {. s7 a" c9 z# z* I& v5 l
ask patches( J% @5 Q9 G. K
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. c$ ]/ a& I }6 o. m7 H4 e9 D' d set intersection? false$ R# X9 A6 P+ x# H# n5 j
set auto? false
% g1 n5 }# @, I5 D L6 N set green-light-up? true: g' D( ]! e( D/ X) g
set my-row -1% F; \3 g+ h0 Q) L$ W
set my-column -1
% ^, n, p. M' H set my-phase -1
* A2 V, D$ b" y+ ?) L' }& d set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets" I" O8 t. x9 e+ X; b5 W2 E, d) s, F
set roads patches with6 `' {: ^+ x6 \0 b: b m j/ |
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
. [# m0 j6 `, l, E, K6 I% B (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
- F; w8 K+ p: C; e: ] set intersections roads with2 s8 @9 V+ M$ Q# B
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and- o0 t# J! o1 \0 u2 e6 k
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 [2 t* j3 C: W" |6 S- D/ k
4 k% ]3 C w' b1 Y. Y ask roads [ set pcolor white ]# j& r9 X J% G2 n) S
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 }& H8 u* x F# { set roads patches with
5 D6 F2 E5 s! \ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or, V& _3 ]9 V. @- {! b; S1 W
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 d, V& p+ J3 t* {, 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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