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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 I" k# L0 }$ [$ s/ snetlogo自带的social science--traffic grid这一例子当中,
- @4 [; p* @0 t3 L2 {globals8 U9 L- |+ F/ W# e& {
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grid-x-inc ;; the amount of patches in between two roads in the x direction% G! H1 l7 F4 N) F; Y
grid-y-inc ;; the amount of patches in between two roads in the y direction
) e. e5 b9 W2 O3 y. v acceleration ;; the constant that controls how much a car speeds up or slows down by if
+ j0 h3 E" H# r, D9 \' a ;; it is to accelerate or decelerate* ^) A, ? \1 ^! Y6 O1 r
phase ;; keeps track of the phase) j) E; r9 g( @
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
" U v/ ]' d( C current-light ;; the currently selected light2 s; Q$ \/ C6 o1 N" E" l% i" F
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;; patch agentsets
8 B4 L/ D( S3 c7 ?) |9 z5 k intersections ;; agentset containing the patches that are intersections
& c+ J& y$ p g4 m$ F roads ;; agentset containing the patches that are roads
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& {( m+ h7 o, W" X% _2 \turtles-own
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speed ;; the speed of the turtle6 X6 P- P+ h' K% f; ^
up-car? ;; true if the turtle moves downwards and false if it moves to the right8 ~+ X& }: z* `3 v h
wait-time ;; the amount of time since the last time a turtle has moved/ {0 Q! ? I: ?+ n& V$ e, V% s
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patches-own
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' `$ \7 C8 s( u; g intersection? ;; true if the patch is at the intersection of two roads
9 e( e, X* _+ k+ w green-light-up? ;; true if the green light is above the intersection. otherwise, false.) ]' _1 w; ] m; x0 w3 E
;; false for a non-intersection patches.1 e5 {4 K; q9 P5 P( e4 V3 y. n, z
my-row ;; the row of the intersection counting from the upper left corner of the
9 n4 R, N, t& u: O1 v) ? ;; world. -1 for non-intersection patches.
8 B% X# U5 Q! {7 Q4 c my-column ;; the column of the intersection counting from the upper left corner of the) j! W+ e' ?) B5 N( f: D
;; world. -1 for non-intersection patches.
3 A1 o* R. j% }# d H3 v, X) j my-phase ;; the phase for the intersection. -1 for non-intersection patches.9 F$ a" x% `7 R( f+ [# P6 V9 x
auto? ;; whether or not this intersection will switch automatically.
1 Y5 `4 X# \; }5 c8 N# O; _8 a ;; false for non-intersection patches.
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8 C( S3 u6 h9 c& I;;;;;;;;;;;;;;;;;;;;;;( z8 [. W6 H2 x9 F
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.( n5 p) i' z& Y7 z+ Z
;; Create num-cars of turtles if there are enough road patches for one turtle to
: Q$ S" e) K4 x;; be created per road patch. Set up the plots.- r# ]( w# \" Y! x4 l
to setup
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% [2 k5 w! @0 i" c. v setup-globals
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; v' r1 W0 f a$ b6 e ;; First we ask the patches to draw themselves and set up a few variables& e/ S0 w- ~5 p
setup-patches
# J5 q; X4 M6 v/ ^( w8 {/ H/ J make-current one-of intersections
5 b3 u, g0 R- S- s6 e# T label-current
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set-default-shape turtles "car"$ V7 \6 `+ S3 T5 ?0 q; \ w% o
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if (num-cars > count roads)+ q8 ~( n3 Y# Y# q& a5 t* w
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user-message (word "There are too many cars for the amount of "
! W% D! @5 j& t# L V "road. Either increase the amount of roads "
: m: R* I$ P- Q: m S5 ` "by increasing the GRID-SIZE-X or "
6 h/ x. i: b$ z R4 s7 w! e1 s "GRID-SIZE-Y sliders, or decrease the "7 y6 S: I$ g$ b) w; G: Z
"number of cars by lowering the NUMBER slider.\n"+ d: k! A, m" b8 h8 e
"The setup has stopped.")
: {! E4 v& q2 e: l stop
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9 E" K1 m, ]- n6 l ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
( r( K+ p! z; q- e$ A crt num-cars
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3 n9 y# H+ ]- K- p# { setup-cars
5 G7 M3 g! |, @. Q# c' P set-car-color3 } z1 q5 f' J+ Q% C: f2 z+ q
record-data1 J: t. ]5 n! _ c0 ?: B- \
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, ?) _" {5 }0 D. l/ H ;; give the turtles an initial speed" x+ m% C4 v6 R% G$ s
ask turtles [ set-car-speed ]
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reset-ticks3 f# W! p- x0 c! y
end
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' D, l: a7 ]& H8 c% N* g;; Initialize the global variables to appropriate values
9 |. }, W5 F8 o$ u' \: K9 ?to setup-globals
8 n7 A' ~* n# q# E |* u set current-light nobody ;; just for now, since there are no lights yet
5 X" H/ g% J ^4 ]8 {6 O3 Z set phase 0
, ?3 `: h. ^5 d& n) b& P( b set num-cars-stopped 09 A4 v+ m. x3 {
set grid-x-inc world-width / grid-size-x
2 R6 O% f j1 {0 u7 I% ?+ x 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 boundary! [; R$ x: Y) f" R9 y9 }, U
set acceleration 0.0990 N2 r* S t, {
end( ~# S% } y0 n' m0 \* m5 `
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,' U! A5 j- r# _+ P- o
;; and initialize the traffic lights to one setting
7 o1 o$ ? e: e3 T/ o( r4 f" Wto setup-patches' ]6 \0 A0 L( Y+ K6 n1 P
;; initialize the patch-owned variables and color the patches to a base-color
* N2 s* I9 r' K+ r* ] ask patches
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set intersection? false
) M# j* k; G" Z set auto? false
! G& S# R: l( Y# t set green-light-up? true
5 D8 x; U+ m' e6 R7 @0 {% w' n set my-row -1
# n. R3 V( D! ]2 T7 [0 X2 A) [7 l a set my-column -1
: C9 E8 u+ t5 T8 I* ?1 [ set my-phase -1, ^2 C% j* G0 j% q
set pcolor brown + 3' u% _( t! W. c$ p
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;; initialize the global variables that hold patch agentsets
- G6 k5 p; n' u) J6 q9 J( A set roads patches with
7 R1 `$ @% J8 ?' Q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
- {4 [! D: u# o1 G (floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 A( i% V' h1 i& Q) N& e
set intersections roads with0 f7 E9 v* M" ^# o/ C
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and; r, M1 m9 _1 `' [; q9 w8 t
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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$ c/ }; o0 p: @" i ask roads [ set pcolor white ]
0 z# y: h0 C9 r2 ]/ {5 ? setup-intersections0 M, a9 l* p1 L$ ~0 E2 l
end7 o+ x4 m1 l; L+ o' x) _" {( c. N- Q
其中定义道路的句子,如下所示,是什么意思啊?
, h$ ^! O1 x; O2 q8 Y set roads patches with$ g) l9 G! _+ d7 o+ C
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
. C" A7 ~1 _8 ^ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
' r6 C2 g$ `9 v* 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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