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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。" l0 c9 Y+ v3 N+ W: x" s+ N; C
netlogo自带的social science--traffic grid这一例子当中,
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* g! y, j3 U ~6 h grid-x-inc ;; the amount of patches in between two roads in the x direction
& F$ c( H- m8 i& x( C$ P! O grid-y-inc ;; the amount of patches in between two roads in the y direction; c2 Y3 ^, r$ y* G- G+ s( O
acceleration ;; the constant that controls how much a car speeds up or slows down by if+ U) _* }* m9 \" k
;; it is to accelerate or decelerate
1 ?! e1 J6 n/ p8 T phase ;; keeps track of the phase" S9 o( K1 H9 V5 m* h0 r! t
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
- B: c) c" M% R) O9 v current-light ;; the currently selected light+ k) B1 d" s; _* A4 W$ l
# w: F. V! M6 I0 } ;; patch agentsets
% y, x4 C# A2 G intersections ;; agentset containing the patches that are intersections$ G7 j, ^1 x9 x5 a% P( F+ k2 Y
roads ;; agentset containing the patches that are roads" e! M' n& g( Q2 h p, d
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* O8 y2 q% f ~/ Fturtles-own
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( @1 x4 m8 ~* V0 a) G speed ;; the speed of the turtle0 k8 W! b2 m0 S2 R
up-car? ;; true if the turtle moves downwards and false if it moves to the right
: d1 b3 e% L* `3 v( _# z. w. l. f wait-time ;; the amount of time since the last time a turtle has moved% c! F. d' E% P# Y) N8 V
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patches-own4 ~) \' F; l5 d0 E- f5 ]
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& ?: A) c# q5 o9 f- y. X intersection? ;; true if the patch is at the intersection of two roads
, K# n. s! T' _5 L green-light-up? ;; true if the green light is above the intersection. otherwise, false.
% o& }9 q; f2 {3 g8 A1 l2 b$ A ;; false for a non-intersection patches.7 w" l$ V, n6 F. E; k
my-row ;; the row of the intersection counting from the upper left corner of the
! k+ }% \6 f- x( K. t ;; world. -1 for non-intersection patches.. b& b* ]6 {8 `, c# Q- A9 y; _
my-column ;; the column of the intersection counting from the upper left corner of the
2 s- k, ^! T1 g1 C. N1 ] ;; world. -1 for non-intersection patches.; E) w! V: d _5 l- j7 _
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
/ F, ?9 r* m2 {7 S6 c auto? ;; whether or not this intersection will switch automatically.
, R- X) D9 ]# |* X& \ ;; false for non-intersection patches./ w# w& w6 f, e$ i3 h: X
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;;;;;;;;;;;;;;;;;;;;;;( T3 V5 J1 \5 A( h/ w% V& U
;; Setup Procedures ;;* ]) T8 N" i2 n# G0 |: n
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.0 g' P) [: w4 @0 G( Y- h
;; Create num-cars of turtles if there are enough road patches for one turtle to
' Y5 i+ Q4 A/ C7 Y- o2 Q% E$ P;; be created per road patch. Set up the plots.8 w t2 D G. `+ q2 w
to setup
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' l8 N1 i0 H1 v! p, C4 `! a4 u setup-globals( r, |4 A4 G) z. t8 [
: d& K) C6 Y! \; v# D" F ;; First we ask the patches to draw themselves and set up a few variables
8 k$ k" _, O+ R( N* Q setup-patches
4 d, k& e. M9 F0 | make-current one-of intersections; G! H3 r3 v% r/ I
label-current
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4 P8 G/ [. A9 R# X/ h& y4 \, r set-default-shape turtles "car"9 R1 C) B* o' y0 a: n
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if (num-cars > count roads)5 B) k- P/ x5 T7 O$ D
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user-message (word "There are too many cars for the amount of "6 Z" g$ E+ @6 \! T
"road. Either increase the amount of roads "
8 r$ U! ^7 |& C: l. y, z "by increasing the GRID-SIZE-X or "
! D' n) s4 Q1 n! X, j "GRID-SIZE-Y sliders, or decrease the ", k+ H' N- z x- x: D# u) t. ]
"number of cars by lowering the NUMBER slider.\n"
3 U5 L3 Q0 K0 E' [" M& @ "The setup has stopped.")
) q5 l2 q! r _8 `1 c4 b' {* | stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color8 l( N' P" U% w g* X9 Q
crt num-cars$ w5 D3 ^: J* K. l" Y* \3 f7 K: q0 X8 R
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setup-cars! O4 X. h, A/ T* M
set-car-color* H+ `9 s7 M. M
record-data
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: `( ^! O4 @" f7 R" [& [, V- p ;; give the turtles an initial speed
5 C( V7 N# n4 p T ask turtles [ set-car-speed ]
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reset-ticks1 o1 i$ G$ @- m8 `: T. t4 p
end
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;; Initialize the global variables to appropriate values& h) R& @/ L$ S2 K
to setup-globals
4 t; r* E. M- k' E4 s) }, X; `) m set current-light nobody ;; just for now, since there are no lights yet' l! g# T( i) W ^
set phase 0
$ v0 c, S* |1 Z* c/ \ set num-cars-stopped 0
$ d' h) P! F- }) W* r set grid-x-inc world-width / grid-size-x. o: r' q8 k; E& j7 M l
set grid-y-inc world-height / grid-size-y
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) p2 c9 z/ Q. u' M ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary* q1 Q( {. }0 r# U& l& v7 f; q
set acceleration 0.099
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9 q2 p8 ?2 g2 Z;; Make the patches have appropriate colors, set up the roads and intersections agentsets,: ]* L# }8 G" {6 }- H. ` I
;; and initialize the traffic lights to one setting
! r; C7 T C" _* Wto setup-patches7 n; M" @' j0 r
;; initialize the patch-owned variables and color the patches to a base-color
Z; [' `' D! R' l" c( _( S1 ] ask patches* s0 R8 A \ U* y" x% M- T- n6 Y$ N
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set intersection? false
3 ?* V+ {- g2 k% [5 x+ c set auto? false
3 S6 B( v* e J* N( O A set green-light-up? true% a; {+ O& B+ S# B" P$ [
set my-row -1
! e. p G/ G% z; ^& c, J' {" I set my-column -1
4 H+ X* K* I9 [5 _4 ^& `+ S set my-phase -1! u: E* O3 ~" C; x/ q& v8 q
set pcolor brown + 3: N. z6 `/ i8 R
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;; initialize the global variables that hold patch agentsets
- G7 b6 m' B# p# _ set roads patches with
" q8 k e9 h1 ]2 m [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
9 S3 [% E, }2 }) C; Z8 Z$ _ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ c9 d% X% z2 t# B7 B# M
set intersections roads with3 C. [" l6 R J8 |
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and/ s* Y, D9 g+ O0 M8 Y. u. M: ?
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]0 n" w8 S- k- O& t
setup-intersections- q ?- I+ _& I1 Y3 I3 v2 E
end
2 }! C' G5 b8 t, O# f; d其中定义道路的句子,如下所示,是什么意思啊?5 y1 w% ?5 A9 }3 I0 E* c
set roads patches with
8 G, J: A( Q- q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
3 u0 e6 h' `% }! Y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
( O+ b* r- L0 ]7 l5 o" V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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