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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。# O8 s1 j' F5 u3 q
netlogo自带的social science--traffic grid这一例子当中,+ ^. Y. z% o) Z/ _0 d! x
globals' D: {7 K2 _+ J1 l3 Y: @% m
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# v1 U4 M s. |0 e' i4 h grid-x-inc ;; the amount of patches in between two roads in the x direction8 \5 \( |3 R( V$ y* j5 ?) V8 S
grid-y-inc ;; the amount of patches in between two roads in the y direction
3 k) t3 D; l3 b0 X3 [; O acceleration ;; the constant that controls how much a car speeds up or slows down by if
' K5 n$ e) Z. o2 V$ l ;; it is to accelerate or decelerate
2 ]* c9 @# J9 K$ g phase ;; keeps track of the phase6 L+ h0 B3 F7 X4 D( e5 Y
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
4 }/ i8 d* m" N6 {% Y current-light ;; the currently selected light! q' j& H# @2 \& B* I
: C: u* ?) Q" }" u( T2 b; ^: c) ^ ;; patch agentsets+ T. J# H* U9 H1 k1 a# \& M
intersections ;; agentset containing the patches that are intersections9 K1 C6 T+ m; C( v2 n. ~
roads ;; agentset containing the patches that are roads! H9 j A. o, z( a3 l
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turtles-own
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speed ;; the speed of the turtle
+ d5 D/ X/ q4 Y2 u up-car? ;; true if the turtle moves downwards and false if it moves to the right
5 [4 Q) p: {# P( D# m wait-time ;; the amount of time since the last time a turtle has moved! P1 |5 _0 P+ i+ { ~/ R# V
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# M! D5 M1 \6 f& X5 E! z6 n8 spatches-own/ x! o S3 O3 `( h* ^* r
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( P$ |1 A* D* F; L% M) [4 z: d& m5 z intersection? ;; true if the patch is at the intersection of two roads6 m4 B9 t# {/ _- r+ k' g- @4 v
green-light-up? ;; true if the green light is above the intersection. otherwise, false.4 Y3 ?5 _; |4 Y. N1 _; `7 J
;; false for a non-intersection patches.
% S. K% z% A3 H' E& C* z my-row ;; the row of the intersection counting from the upper left corner of the6 a! t7 J' P' X ]
;; world. -1 for non-intersection patches.
% Z5 r' x- W% M# L9 l" u$ T, F: F6 s my-column ;; the column of the intersection counting from the upper left corner of the
6 P/ K: \9 Z* E! L& K+ z ;; world. -1 for non-intersection patches.7 c9 X6 \4 c: G! H8 P& S; L$ ?
my-phase ;; the phase for the intersection. -1 for non-intersection patches.! [8 ]+ }, j, q4 \; x( [
auto? ;; whether or not this intersection will switch automatically.8 V, p% Q, G5 a( e
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
9 V' n/ b/ W( Y: g1 I;; Setup Procedures ;;# ]" A/ x: a' }6 f& b) y
;;;;;;;;;;;;;;;;;;;;;;* P* x( \, H- T# Q$ j6 b E* q
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;; Initialize the display by giving the global and patch variables initial values.4 B/ m& z6 V) c9 z4 m* [ ]
;; Create num-cars of turtles if there are enough road patches for one turtle to2 B; _% p; U! x& ?2 @; N) h4 C
;; be created per road patch. Set up the plots.
4 |7 A, f8 J1 z B- t, O" t' sto setup
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& `: K4 P% C1 N. P2 e+ j4 I* P setup-globals/ m( K5 i: f4 b2 M
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;; First we ask the patches to draw themselves and set up a few variables
5 T9 G. s2 A, H- C$ Y3 y setup-patches
9 Y) n# i P9 D: s7 ] make-current one-of intersections
; X# s6 J4 [9 \6 F8 y, H4 H" D- n9 l label-current% \) _% D) q3 o+ ~7 I) u
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set-default-shape turtles "car"+ I$ O* ?( x: M8 ^5 D, c% ?- F
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if (num-cars > count roads)
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' V/ S% q7 E* D; v: W user-message (word "There are too many cars for the amount of "
9 R0 b# s0 c/ r: E5 f. x "road. Either increase the amount of roads "
% w3 D7 L' q2 w$ F& r( Y- A, `* V "by increasing the GRID-SIZE-X or "
7 f5 C3 d8 T# x( }& {$ S7 @; k "GRID-SIZE-Y sliders, or decrease the "
& \6 T" m7 l4 s& I! m! Z5 C2 @ "number of cars by lowering the NUMBER slider.\n"
0 g, i5 m' z8 W* D9 K' L "The setup has stopped.")
4 M1 Z4 u5 r5 O2 Q) T- m9 K( M* V stop
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0 Y7 [/ l) _5 s( E ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color5 o/ t8 P5 ^ }5 F
crt num-cars
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setup-cars
& T: j$ Z1 s- |, z2 f+ O set-car-color
, N. [/ A9 [1 a record-data1 F. W5 Z1 R' D& l6 F6 q% j
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;; give the turtles an initial speed* S I$ N2 m# s( I
ask turtles [ set-car-speed ]
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) W# V1 Y' H- v2 f reset-ticks) S" c- b/ K: X# _. t. l: l
end) q7 P1 a7 n+ B0 J( R# ~$ X, [& a
8 m# W3 ], A/ }8 K. M' k( T5 G+ ~;; Initialize the global variables to appropriate values0 U+ v% e7 a# W5 f' [
to setup-globals
( u* k1 y" m# F# W( w( R" o set current-light nobody ;; just for now, since there are no lights yet! O/ R0 { H+ s4 o G0 h" m
set phase 0, L- P% b, n0 R* ~
set num-cars-stopped 0
9 R/ C2 B' B# T( g, n set grid-x-inc world-width / grid-size-x3 p" @! `- Y d
set grid-y-inc world-height / grid-size-y8 K1 g1 ?- U: O2 u
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
' U' |$ n: `0 l2 Z4 O Z set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,9 q ]' [. k: r: o2 C: x+ {
;; and initialize the traffic lights to one setting
! e! {7 @6 x- F6 Q9 f4 qto setup-patches
# ?3 `. g# O+ U" D" e# ? ;; initialize the patch-owned variables and color the patches to a base-color: @ g( }, h9 R8 _( F; h( X3 \# ]1 k% E
ask patches
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0 {" ] @5 ?9 Y5 m set intersection? false
- o7 G* g" M D: j; x* n A( y( x set auto? false
( V. j8 d1 P( ~; x0 C+ o set green-light-up? true, z" t3 j: D7 W% D- @( C' Z) |" I0 L
set my-row -1' J- S6 W! o0 U' g2 b
set my-column -1+ r* m2 K/ H+ @: I; O- `, ?" F8 v; Z3 G
set my-phase -1
: w: I9 C8 c/ F# y# U set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets, \. ~9 i m. @" @4 G1 H
set roads patches with
! T. e+ ?/ M0 }' V [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or. O& ]% F% x5 N @$ X. T3 K" n3 z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]! \% X) w6 A# s) ]' P
set intersections roads with
4 f X8 X- O: s8 \' E \ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and3 H X5 I/ ?6 Q7 ?2 ]
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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- [5 }' _9 ]- |7 o/ F4 r$ [2 { ask roads [ set pcolor white ]" p5 ]8 m% @ k& [: U" r
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?2 L0 @4 v! y0 ^; H) K
set roads patches with
* q+ z( h- E' y [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or0 v2 b9 U4 O6 w
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 S+ y; o9 @, [, K' U5 N. x- j# D
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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