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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。
, O. h8 [5 P3 i; ^9 ?9 _netlogo自带的social science--traffic grid这一例子当中,3 X% Z3 S; N# G$ C4 d
globals
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* K& L( c4 U8 y! k1 d: T& K1 | grid-x-inc ;; the amount of patches in between two roads in the x direction
; p+ w& Y( p- \' \, [2 X grid-y-inc ;; the amount of patches in between two roads in the y direction
- P) t3 i$ H; G acceleration ;; the constant that controls how much a car speeds up or slows down by if; J# V8 w+ Y9 e/ e
;; it is to accelerate or decelerate
% B! k' ^5 n* H) {) H. q phase ;; keeps track of the phase$ C$ u' H2 _0 q- j: |
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure2 w4 |& N7 J: H0 A( I* `) N
current-light ;; the currently selected light' s: ]% W: F: D5 F
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;; patch agentsets1 ^3 m/ @, ?! n9 W ^. u5 v
intersections ;; agentset containing the patches that are intersections
B9 v7 g7 d, q$ _3 h roads ;; agentset containing the patches that are roads4 b* x. o% Y% x- l
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5 I/ J5 p1 d# ?turtles-own
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& W% c% k$ \; C! N( t4 N speed ;; the speed of the turtle; `/ r& K0 z/ X4 N4 P0 |+ ]: T9 k
up-car? ;; true if the turtle moves downwards and false if it moves to the right2 b2 ]! F# P4 k7 m8 a5 U
wait-time ;; the amount of time since the last time a turtle has moved# g( M6 Q# Z1 f* F0 t
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patches-own
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. O" Y' A" Q# V6 R intersection? ;; true if the patch is at the intersection of two roads
2 z2 {! z2 w& [' ]6 W$ `/ Q green-light-up? ;; true if the green light is above the intersection. otherwise, false.
' S/ U* I5 |: D ;; false for a non-intersection patches.
: l; i" f: m1 N- o my-row ;; the row of the intersection counting from the upper left corner of the7 j' G* |4 B' Y+ ^- ^
;; world. -1 for non-intersection patches.6 a, E2 ]5 {+ t+ ^
my-column ;; the column of the intersection counting from the upper left corner of the q. |5 j* b$ n) A- f9 v
;; world. -1 for non-intersection patches.
. e i# [) I* }6 [+ Y- }' D my-phase ;; the phase for the intersection. -1 for non-intersection patches.! i7 o9 D9 o( z& ?* I
auto? ;; whether or not this intersection will switch automatically.
" C k) J& k7 E! D5 t6 s5 t ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;! j2 _% H u! ]9 J' j2 M! H+ P. z
;; Setup Procedures ;;5 x( B1 j: q& \, L4 @5 |4 n
;;;;;;;;;;;;;;;;;;;;;;4 k! B5 e- ~; R P
~4 L* p$ n; ~1 T;; Initialize the display by giving the global and patch variables initial values.
3 q; x3 T% m( `9 {% B' ^/ P2 B;; Create num-cars of turtles if there are enough road patches for one turtle to2 O2 R" p* f, [" K
;; be created per road patch. Set up the plots." y H* x: o2 g, g# U, K- d' }
to setup6 p/ |8 O4 a) `
ca
6 x8 @* v: o0 w& }. ?# |- R" R9 k setup-globals
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( N. o; J% W. w9 ?- s" a ;; First we ask the patches to draw themselves and set up a few variables+ v3 _2 g$ {8 M. ^% z
setup-patches4 t6 u3 ~0 y9 a1 E' a _
make-current one-of intersections- s- M, `, r+ z& K
label-current7 @, _( o1 M# X
$ K* o* t& m! }0 q9 o set-default-shape turtles "car"9 f4 r. s; s) `3 @5 x4 N l7 N
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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 ") Y1 N, t/ b3 s1 p7 {$ _
"road. Either increase the amount of roads "* R4 ?+ P9 |3 ]% _7 M# T9 Z
"by increasing the GRID-SIZE-X or "
3 H( [1 k6 |- q, C. G "GRID-SIZE-Y sliders, or decrease the "# d7 J/ K6 E; {, J9 _% F7 c0 l
"number of cars by lowering the NUMBER slider.\n"
5 A+ N- r$ C; H8 k. n3 b0 f "The setup has stopped.")1 T8 Y, c3 M5 L1 n, |6 t8 T
stop; L3 ?* v8 G# {; [% k5 M2 M; |* N
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color! L; P& {% J: X/ r, T
crt num-cars4 V2 o( B, X6 k
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setup-cars" z. S& m9 y/ I6 |# k$ I; @
set-car-color
! z }) p5 [# e, K# q( x9 m record-data$ q" {: ?) x0 D. {6 l. Z( p
]
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;; give the turtles an initial speed
- [9 m9 V* E, o! }- Z4 }- M2 D A ask turtles [ set-car-speed ]+ q4 H7 ~& ] _% \! i) ?0 A
- [5 v4 k" F, E) m1 w reset-ticks
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;; Initialize the global variables to appropriate values5 b, h) x* ^; k: j7 I6 p5 _
to setup-globals' j3 ]1 J* k2 s8 G6 ^, B+ O" k/ h
set current-light nobody ;; just for now, since there are no lights yet) W$ \3 U L9 F) U
set phase 05 c2 h8 ^) Z: z( |9 {
set num-cars-stopped 0
/ R$ ?( @3 x% e5 G2 U; s4 ]' [; X set grid-x-inc world-width / grid-size-x7 M6 P8 D B7 ]+ `8 Y
set grid-y-inc world-height / grid-size-y
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/ q0 r* n: Z" }# G ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary8 W2 {; V/ ?: w& d4 I0 s9 s% Y
set acceleration 0.099" k. z$ e! C @+ T2 J
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
, f0 ]( S3 _; o8 e$ i;; and initialize the traffic lights to one setting
' }( c5 v# \1 S n9 ?1 C2 ]; P( Pto setup-patches
" ?# q( O* d6 v& X+ o7 l ;; initialize the patch-owned variables and color the patches to a base-color
- V- @& O& z/ u ask patches' M5 t4 `1 w$ y" \# o
[
( F' c( B1 j% u/ e set intersection? false
% n u8 k8 ^1 } set auto? false
+ P8 B0 ] g$ A set green-light-up? true# d1 P; c" @2 O4 U
set my-row -1! [* U% ~" }+ v+ S! q+ F
set my-column -17 j: k. w3 q- T$ i, V6 e/ b+ x9 A
set my-phase -1
~5 L9 D. x! M# F( e" \: P set pcolor brown + 3) {% u( {2 g: S" i$ t$ J9 N/ A
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5 E9 Y5 A- D4 B. A3 e ;; initialize the global variables that hold patch agentsets o" z/ R) I1 s) o6 _" B1 t& S0 T9 m
set roads patches with
# W! o+ b- R+ _9 G [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
' Q3 Y8 Q4 r4 w5 R (floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ ]+ s# r% [6 B4 Y
set intersections roads with
# W( D. j5 C6 p$ w8 f8 w [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
# D, v( p4 f3 O! r (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]+ t8 i6 b z* ?+ x4 j8 Q$ ^8 J
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?
9 R2 _- i* ~: z: J# n6 q set roads patches with
4 ]/ g l$ S/ Y' }. v0 B [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
0 |% `5 \8 w4 i. d. E: `( U (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
! m. a7 y0 }& b* L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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