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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。1 A `1 ?( E/ k; o
netlogo自带的social science--traffic grid这一例子当中,
' P U! Q; b+ F& aglobals
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4 M! D7 v8 R/ M! T: W- T1 q# z% z$ Y grid-x-inc ;; the amount of patches in between two roads in the x direction5 D6 z) {. K; Q7 [- s$ B' M
grid-y-inc ;; the amount of patches in between two roads in the y direction7 Y s( L* X5 Q0 N9 H
acceleration ;; the constant that controls how much a car speeds up or slows down by if
5 z0 ^; Y- R+ {5 O ;; it is to accelerate or decelerate; [, N, {: \" N& G6 v! U
phase ;; keeps track of the phase. T$ s# S2 W( l4 T, a4 I8 t
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
: V* G* C' p3 w" ^# j) |3 N current-light ;; the currently selected light
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. k+ j+ S1 \, x0 U( g6 k ;; patch agentsets0 g7 Z. Q6 K. m& @
intersections ;; agentset containing the patches that are intersections& q! z6 M; w" |. F9 _" ]
roads ;; agentset containing the patches that are roads) |+ H, G3 z/ U
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turtles-own$ k. C% i J5 g# m
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speed ;; the speed of the turtle
' g7 k( o, n3 ~* A# v6 j6 D' ~& u4 ] up-car? ;; true if the turtle moves downwards and false if it moves to the right1 t4 R+ a4 G3 b; ~3 G% p% r1 D
wait-time ;; the amount of time since the last time a turtle has moved2 a/ B$ w1 t8 I3 \+ q
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patches-own I8 b l! M8 C' T
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intersection? ;; true if the patch is at the intersection of two roads
. @' n1 Y, H& D! _' ]: t' J green-light-up? ;; true if the green light is above the intersection. otherwise, false.
' M# T0 z1 i/ |% L4 D ;; false for a non-intersection patches.
9 H7 e' Z" F9 V+ v" ]$ t7 n my-row ;; the row of the intersection counting from the upper left corner of the
! D8 H, { s) w m1 m$ I1 W0 \ ;; world. -1 for non-intersection patches.
/ c: |: j1 u1 q% Z6 M my-column ;; the column of the intersection counting from the upper left corner of the
( Q/ J9 a" [$ T7 R+ H# c# q$ v ;; world. -1 for non-intersection patches.
# b1 ~) {* g8 {$ B my-phase ;; the phase for the intersection. -1 for non-intersection patches.
, K0 _9 k) X* C {& p) h auto? ;; whether or not this intersection will switch automatically.( m7 _" ]3 A% v0 w9 v
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;& N6 q% s) d. @! [6 a
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.8 }2 W; z! e7 A6 q* f( _
;; Create num-cars of turtles if there are enough road patches for one turtle to
! d" r6 n9 n3 c/ ?;; be created per road patch. Set up the plots.
" ~ H) J* a0 K: V: r8 Sto setup
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! h4 W2 P) F9 t L* L0 } setup-globals1 J1 U6 t- }6 h
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;; First we ask the patches to draw themselves and set up a few variables, C2 V D! ^& g, d9 e! t
setup-patches
* ]: X- L9 \. q1 _+ t2 z make-current one-of intersections% R* ~/ o- m) {2 D
label-current
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set-default-shape turtles "car"
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. p1 z& ^; a/ Z( y5 X$ P if (num-cars > count roads)& y. d( D. i4 e: O7 o
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- z6 S& A* o! Q& \( R user-message (word "There are too many cars for the amount of "* x9 u4 `2 a/ Z2 |% e/ H
"road. Either increase the amount of roads "- D, p" a( f, D& D
"by increasing the GRID-SIZE-X or "
1 w9 E P9 M( W" O9 [2 U "GRID-SIZE-Y sliders, or decrease the "
" D# w, v5 Z9 C$ c, x& r "number of cars by lowering the NUMBER slider.\n"
; H+ R4 f: W3 W6 I! W6 L "The setup has stopped.")6 t! F2 P- d) H5 {7 m6 A
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color8 `& x' n! ^3 I) C& v( G
crt num-cars8 |) r# j/ k; w+ G
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- O* ]2 \; p4 z% o; f setup-cars: r7 k+ a: H. |5 q' f
set-car-color
( c* f O2 r( E( h; V9 W record-data
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( K/ w" }$ R8 B, V0 z4 G' C ;; give the turtles an initial speed
8 |, Q# K4 |5 \8 a6 {* q1 Q ask turtles [ set-car-speed ]
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reset-ticks
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;; Initialize the global variables to appropriate values! {9 ^% h2 q. |$ `% B" }
to setup-globals
" s$ l( r3 e3 B/ s! G set current-light nobody ;; just for now, since there are no lights yet
, T" R) R/ K. p8 T* f6 p- N1 S set phase 0
4 q' b2 p/ U" J* ?, P2 Z set num-cars-stopped 0
8 t$ x$ U' |5 H) B set grid-x-inc world-width / grid-size-x
+ n9 R5 E9 |6 T, Q2 d& R& O7 H set grid-y-inc world-height / grid-size-y
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! P7 s- I& ^& ^1 b0 w. N9 x ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
- S7 [2 ?& }1 u3 O set acceleration 0.099( i, z7 t2 ~" q' D6 o, E
end- g: Z3 }7 a) ]
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
$ u m& U- @8 U) B) I0 p, g0 [# G;; and initialize the traffic lights to one setting* K" _4 B/ u2 X. _8 X- M" r% K' ?
to setup-patches4 O9 y @ R Y. X0 z1 z- o! _; x
;; initialize the patch-owned variables and color the patches to a base-color
9 t/ n$ I. B/ E' Z x ask patches6 R2 ?( c* P* R Q0 s5 l
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9 y- j- q7 a1 q. ] set intersection? false u/ s' r/ ]3 _( V' B! h$ V4 d. S$ W
set auto? false% }6 L9 p ?+ L5 |2 ]7 r2 g
set green-light-up? true
" G) B2 s+ ]% M+ N- s, Z set my-row -1
4 O( C/ z7 W5 \ set my-column -1' t H ^" y, ]! X: g2 }2 ~
set my-phase -1
# I9 Q0 {8 e, I0 t- V7 I: q7 v set pcolor brown + 3
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$ T& n$ X( |: e+ Q" g. F; h% h, ?. \ ;; initialize the global variables that hold patch agentsets
* B! r6 J: H; {, _5 `' ` set roads patches with+ |) ?; Q, V; Q# x. s/ ^+ n
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or* W! n" m( g, V, d: Y# f, |
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 h! m1 o5 @* m8 ? set intersections roads with2 S1 ^8 f& B. c2 X; t
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and) C7 J: \- V$ B0 R2 k: y5 c- F
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]! u* N/ y8 D' G* s- q5 [- W+ u( S
- E8 g! [$ k) F1 e" \ ask roads [ set pcolor white ]" } W8 D$ D. x2 W* ^# G9 G' {
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 ], L, t k6 _# @9 }7 F
set roads patches with$ \1 T1 O' I" x# h
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
& x7 W& T) Z7 j' |& ~. ~/ S2 ~ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) P" W/ e) o+ c2 U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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