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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。5 O! | T# S2 |1 k% f k! ^
netlogo自带的social science--traffic grid这一例子当中,$ {( o1 t @1 a% Y, a3 g
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction, X6 ~7 t2 e# H
grid-y-inc ;; the amount of patches in between two roads in the y direction
8 Z% \8 g8 T3 V4 x5 j acceleration ;; the constant that controls how much a car speeds up or slows down by if
( z1 r* ~3 Q" j& |# k/ N" y ;; it is to accelerate or decelerate
4 P$ [( Y- G6 x3 A! \ phase ;; keeps track of the phase( u! C$ s3 P) W( Y) b: o* Q
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
5 E6 D# o) n- x current-light ;; the currently selected light
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;; patch agentsets
: v: x5 Q' A8 n* v intersections ;; agentset containing the patches that are intersections
! R' z- U) f8 N" J" o roads ;; agentset containing the patches that are roads: b. f4 H( Z2 Z& E! Z) f6 `: L
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turtles-own
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speed ;; the speed of the turtle
7 s: Y; @+ N9 q2 a& X up-car? ;; true if the turtle moves downwards and false if it moves to the right
) b# F+ |1 q) ?5 r% f# Z3 u+ C$ Y& S wait-time ;; the amount of time since the last time a turtle has moved
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! p! G9 P1 c, {! l8 Kpatches-own5 o6 f+ k3 z4 S2 E# C6 G
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$ v; P# u0 _; X intersection? ;; true if the patch is at the intersection of two roads
9 }1 ~* l; R2 g- A* t4 | green-light-up? ;; true if the green light is above the intersection. otherwise, false.
" b! n7 Q9 z9 S& \8 b ;; false for a non-intersection patches.
5 g; n. ]2 @( a my-row ;; the row of the intersection counting from the upper left corner of the7 p' R# X; V+ W, t
;; world. -1 for non-intersection patches.
" v# X+ U, {# i5 ?% _# g0 X my-column ;; the column of the intersection counting from the upper left corner of the
, |% X* @4 S- x M ;; world. -1 for non-intersection patches.' t: \! ?! n2 x( b3 ~
my-phase ;; the phase for the intersection. -1 for non-intersection patches.4 L& W s9 h6 Z) Z- _3 @
auto? ;; whether or not this intersection will switch automatically.
2 a3 `* n1 f" n. k ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;1 ]3 a* V" J/ R# e
;; Setup Procedures ;;' B. X D7 i) \
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
! U, B8 b8 u0 e. v;; Create num-cars of turtles if there are enough road patches for one turtle to3 O5 Z1 @9 j; b$ E3 a L0 \! \' A
;; be created per road patch. Set up the plots.. _. f7 g! P( X; q8 O
to setup
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setup-globals; A; \+ |# V0 k
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;; First we ask the patches to draw themselves and set up a few variables+ X0 i$ T, z4 f1 a0 H: l0 S
setup-patches
/ A$ m+ C: T5 s* q, E0 h9 | make-current one-of intersections
0 A$ O9 S6 e! r( ^' j% D" o4 U label-current
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, z" f4 o' y N$ R4 h: K3 H set-default-shape turtles "car"
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; l: Z% h+ d( l" } W if (num-cars > count roads)
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& c2 X: ?8 K! p/ u user-message (word "There are too many cars for the amount of ", I" q$ R3 v1 B
"road. Either increase the amount of roads "
) O+ ]/ ]# F/ A6 l( F! l2 W "by increasing the GRID-SIZE-X or "! ~5 c& e4 ]& x& ]8 r# t, D
"GRID-SIZE-Y sliders, or decrease the "
% g/ @5 |2 k. a# B6 o "number of cars by lowering the NUMBER slider.\n"
; A7 w# ~3 j h+ w# K "The setup has stopped.")
5 C/ u. }; ]' K2 F0 X stop& n+ Z4 X# n! x
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color6 O- V, u3 P$ I2 R9 _
crt num-cars
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6 I/ y" x* e7 b7 w0 K& x setup-cars7 k$ F" }1 R: i* `) S
set-car-color
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;; give the turtles an initial speed& V3 F5 s# h! ~9 t6 [9 b
ask turtles [ set-car-speed ]1 M3 }& C. Q8 A7 @ v8 l
7 j" X* W0 g% u, @# F' Q reset-ticks" ~2 q% k! {2 j8 U+ ]) L4 e
end! t7 ^1 P- K) |" e0 e
3 x% z* O! H6 p7 ?. m: w8 y8 p;; Initialize the global variables to appropriate values# D' j ^; O7 `0 B, l
to setup-globals
: t" l% ~( Y7 u. S set current-light nobody ;; just for now, since there are no lights yet
, }9 ?* E3 ]' K5 i$ v0 Q8 h set phase 0; e1 G5 O3 B3 d7 H7 G b
set num-cars-stopped 0% A/ u7 j; H, s6 b5 Y
set grid-x-inc world-width / grid-size-x
) l4 K( b* e% p+ F! x set grid-y-inc world-height / grid-size-y* _, H) |( v1 G
+ W) Q! l2 J$ A6 _- P1 [ ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary/ E2 I: h5 a0 B$ f9 S5 b" ^2 W1 V
set acceleration 0.099+ S/ r9 j4 T* Q
end3 q7 A/ L e1 J: h* L$ B, b7 L
* i# E) O$ K- Y4 g# S |* j;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
2 v. _( K5 o+ c' d1 q; l" i% M;; and initialize the traffic lights to one setting
8 n8 S$ U( S u2 H" Fto setup-patches
" C" R8 s; `# n( e2 g& } ;; initialize the patch-owned variables and color the patches to a base-color
0 V" Q: O1 J4 D, \1 | ask patches
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set intersection? false
4 |# d3 y- } C. M. }, _ set auto? false" K9 M6 k, g# C# L/ p r
set green-light-up? true
* X7 f" f0 x/ h& E/ [ set my-row -1
. S* B$ p2 b" P) ~3 K/ U0 K# j) @ set my-column -1 K7 W7 r' Q7 b! F [9 Y
set my-phase -17 N9 W( ]* {% n. f9 [: y- S
set pcolor brown + 3( k( [2 t( D4 F
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9 t; r/ H/ g' w5 y4 l ;; initialize the global variables that hold patch agentsets( V8 x5 Y7 o0 w j4 S1 f, T
set roads patches with% H2 D. t3 @0 L* [ O% K1 X7 A
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" j, `. _% o5 q- i (floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ d9 c2 H+ c: }
set intersections roads with
1 u5 t3 }! ~4 E7 z5 ~! P, a [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and7 j+ Y0 O. Z" ]% R& [
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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- C, l. z. q2 y. k! U ask roads [ set pcolor white ]' d2 _1 g$ d. |* s2 a
setup-intersections0 j) P' \: h9 B# j
end# H8 b, T/ {& a$ A) k) x$ z
其中定义道路的句子,如下所示,是什么意思啊?6 M7 V0 Y9 a0 i1 l0 p6 T
set roads patches with
; A# n# O- f6 E" Z, O9 H7 @ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: A6 O/ `6 D/ d& v ?0 g# n: X (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* g. U8 }# K+ b/ y& r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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