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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。/ t: a3 n+ b4 s) I- Y( V0 l
netlogo自带的social science--traffic grid这一例子当中,
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grid-x-inc ;; the amount of patches in between two roads in the x direction
8 h4 s: Z2 d- R( g1 K* l grid-y-inc ;; the amount of patches in between two roads in the y direction+ v; r( _* N* ]# ~% J
acceleration ;; the constant that controls how much a car speeds up or slows down by if
" L- q, E" O" T5 B- I- M" | ;; it is to accelerate or decelerate
' e( n1 R n2 x. H0 M phase ;; keeps track of the phase# c, l7 v2 r! b: a$ {# h" N9 j) ^
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
. V/ O2 r" Q% ] current-light ;; the currently selected light
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5 B, g$ W: J V& K! d0 @& V" i/ i ;; patch agentsets
\; o" z3 c3 O) M0 }7 V* E% U/ o( _ intersections ;; agentset containing the patches that are intersections) S* q1 l3 A- R& \9 g
roads ;; agentset containing the patches that are roads
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turtles-own
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4 h2 ?. f* G2 Z( O speed ;; the speed of the turtle
9 |: |- C' W/ G up-car? ;; true if the turtle moves downwards and false if it moves to the right+ C" y* Q: K0 h; {
wait-time ;; the amount of time since the last time a turtle has moved
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1 A' w! _3 a3 a. |0 j opatches-own# O* R/ W M+ X. x# K
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: p. H4 n. D% r' K intersection? ;; true if the patch is at the intersection of two roads; T9 G" v$ b" m/ ~% L/ {+ }: z; D8 p0 E3 h
green-light-up? ;; true if the green light is above the intersection. otherwise, false.! v' t% q4 }8 g2 V) t/ U* c
;; false for a non-intersection patches.* c: |% p( V, i0 k0 g. D
my-row ;; the row of the intersection counting from the upper left corner of the
& Q% C5 g( H' y* X$ j# L0 @( A ;; world. -1 for non-intersection patches.. S6 `5 H8 }- S! v% n
my-column ;; the column of the intersection counting from the upper left corner of the- \) x/ O W) X7 A3 ?2 ~, k8 V
;; world. -1 for non-intersection patches.8 g! Y. j# i9 c% n) C0 H, m7 o
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
: @" r0 C0 _0 y# C2 `( E+ p2 j- X auto? ;; whether or not this intersection will switch automatically. V1 h6 n3 T/ U0 d& K
;; false for non-intersection patches.3 V( Q! ^; r; j& f3 e: G
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4 K9 e3 A4 G1 Q- ~$ j& P;;;;;;;;;;;;;;;;;;;;;;8 e! }! x, M k& O( o0 h
;; Setup Procedures ;;
9 _) n' |% k; {5 q' z( R;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
" X! E9 ]4 ]0 a, l" |;; Create num-cars of turtles if there are enough road patches for one turtle to# @/ ]4 q3 h8 |' T2 U5 ~+ R. f. c
;; be created per road patch. Set up the plots.
$ u5 U8 F/ I7 e- A; ~3 z C3 P/ Y6 ]to setup% W& b) D1 U, Z. c+ m
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setup-globals6 b; d1 A" `/ ?! Z
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;; First we ask the patches to draw themselves and set up a few variables
( F+ b$ y) F a/ F setup-patches
/ S3 ?/ p; V& X2 P5 ^) v* v! z make-current one-of intersections
6 m; ?( p2 p1 u$ ?( O label-current
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, L; v6 J% a! y set-default-shape turtles "car"4 _( G1 B i. m3 Q2 ^
5 l0 T, r# @ }) B3 J" ]& S if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
2 S, R1 E A! X# u: |# Q "road. Either increase the amount of roads "* ^' u+ }: _! D; a% ?! j% E
"by increasing the GRID-SIZE-X or "
# D& z' ]) B2 ^& N" ?) p "GRID-SIZE-Y sliders, or decrease the "
. F5 a7 _2 F" H X s# j Z$ ~ "number of cars by lowering the NUMBER slider.\n"" T. \1 |3 _+ E- L' ~9 B9 `8 T7 ]
"The setup has stopped.")
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R) l% a+ x& N" b ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
3 T* n. h4 A6 M1 m8 q- H- ^6 X+ P) K crt num-cars
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setup-cars5 L% a% z. c( X' Q% h6 ^, R
set-car-color
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;; give the turtles an initial speed
. A1 H$ c: M6 \6 D3 r. k ask turtles [ set-car-speed ]) y" n0 k' l% m g/ p# m; x C& `- U
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reset-ticks4 W, @; S' x( k R, X
end" D: _; y- h$ p: j" H4 r
1 x U9 \; T1 e+ z# V/ x;; Initialize the global variables to appropriate values
6 @# |3 G" j9 sto setup-globals
, {* W8 O3 _& M' J7 p0 F" R set current-light nobody ;; just for now, since there are no lights yet* t- L5 L" p! ]
set phase 0- t. d' r) E; A1 f, j
set num-cars-stopped 0
8 e# H& G, Y9 p. W7 c. O3 K set grid-x-inc world-width / grid-size-x9 ^/ |1 ?0 |; U, G @" i P
set grid-y-inc world-height / grid-size-y7 w; P8 ^- j& J) e& Y
_( F+ G5 d2 K O ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary& G- M. q5 H: }& e# u
set acceleration 0.099
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8 f! x' _$ U, G: m3 ^;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
+ v' E. U8 {3 c;; and initialize the traffic lights to one setting
. p+ b7 d/ c |( Q. _: B& H7 ]to setup-patches3 P8 s* u$ r1 U7 T
;; initialize the patch-owned variables and color the patches to a base-color
5 j: d; s# o0 l/ u/ }6 V6 |0 z ask patches
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set intersection? false
* b. p! | v3 u F2 _8 c/ b set auto? false
' }8 F$ f6 ~: D( {& ] set green-light-up? true* ~9 \7 h& }, W* i' n
set my-row -1
3 M. m# P! l: ~, b set my-column -1
7 J7 E" t4 c7 B( Z. r( g% ^! m set my-phase -1% f* L# `! Q: V, G" I% {
set pcolor brown + 3
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: `, \/ u6 ^4 g' A ;; initialize the global variables that hold patch agentsets9 E5 t. o; x1 ~" P3 |6 A
set roads patches with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]# y3 J1 M' \% F& O( A9 |: y0 p
set intersections roads with
! C$ e# j7 g5 P3 D9 z2 K4 g ~ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
0 v) Y& i: A% C4 ^( e4 B! d (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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0 q/ _- A# H) e# S- _, Q" H/ x ask roads [ set pcolor white ]
3 l* B4 J: n% ?5 H: l2 L4 x5 I 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?* X' Q- [, p: z
set roads patches with) l A6 [8 P& `! Y T) L! L
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" ]! G% ]; j+ T& i% o! a# b
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 J& Q) B6 I9 v% b, \$ p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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