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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。3 L6 L. j- m. c
netlogo自带的social science--traffic grid这一例子当中,
$ L$ D/ H; T8 k8 Pglobals
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7 x4 U9 p; g' C, J$ b( ? I grid-x-inc ;; the amount of patches in between two roads in the x direction0 T; r( \. F" n8 a5 W; |4 Y( p
grid-y-inc ;; the amount of patches in between two roads in the y direction
4 w! K( u$ A0 _8 e" v$ d; h acceleration ;; the constant that controls how much a car speeds up or slows down by if4 k. P0 `; l! j$ f
;; it is to accelerate or decelerate
1 G# ~6 j3 G, x" y3 j phase ;; keeps track of the phase
. w2 g3 c/ I# Y8 E9 c+ b num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
' b! C, k; R" [6 B# f8 n( r7 _+ M current-light ;; the currently selected light
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# k6 [ m7 V0 d" W0 i. x0 d7 O ;; patch agentsets# @9 O G7 b* f3 f+ _
intersections ;; agentset containing the patches that are intersections5 V. L, |) I E& M
roads ;; agentset containing the patches that are roads
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( Q: D# o, p+ [8 }# f+ Gturtles-own6 A( L u3 N7 S: F+ C
[
+ J! v# e: B% U# d1 k speed ;; the speed of the turtle) c" L3 I( r3 h6 z& a
up-car? ;; true if the turtle moves downwards and false if it moves to the right
2 j. |: u2 u, m. P wait-time ;; the amount of time since the last time a turtle has moved
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: e6 s$ X& x6 P# Q# ?. Ypatches-own
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intersection? ;; true if the patch is at the intersection of two roads+ y& g% Y' ^7 p( m& A. E. C
green-light-up? ;; true if the green light is above the intersection. otherwise, false.. t# F2 }$ |& E2 D+ h. M
;; false for a non-intersection patches.
0 j4 R% Q, ]- c1 `5 K" [8 ] my-row ;; the row of the intersection counting from the upper left corner of the* p0 K! G% f& {
;; world. -1 for non-intersection patches.
# M) i" ` }- Z) ^$ l! v- K3 Y my-column ;; the column of the intersection counting from the upper left corner of the
U9 g5 {: t. q$ z) |6 g ;; world. -1 for non-intersection patches." Z4 l$ ]. y$ G8 X* I6 j
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
: }8 V( s9 @8 [ auto? ;; whether or not this intersection will switch automatically.7 ?0 W1 ~) C( ^; Y }; p
;; false for non-intersection patches.: L" W# B7 b; H/ l, o8 R
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' K3 ?7 N/ i4 r" p( _' i;;;;;;;;;;;;;;;;;;;;;;
& Z' j! w/ [/ ?( Y;; Setup Procedures ;;$ t+ T$ v& j* r5 I
;;;;;;;;;;;;;;;;;;;;;;
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* s" ^! ~1 E; J;; Initialize the display by giving the global and patch variables initial values.
' ] b1 X& R- m0 g( S' U3 C;; Create num-cars of turtles if there are enough road patches for one turtle to& e/ Y1 t! x I+ U" j- d0 X' k
;; be created per road patch. Set up the plots.( u! E; h# |9 L8 y w; H% f
to setup
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4 S! n, @, k: u setup-globals- h$ q- j7 a$ j, r
- B: Z" w8 h0 X& `9 Y9 ` ;; First we ask the patches to draw themselves and set up a few variables
# t5 B! Y+ X% F4 z$ @) S setup-patches8 v0 t4 Z, e% J+ B2 [/ L4 A
make-current one-of intersections
! _1 {# o C2 J label-current
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2 P' l! `& U8 u set-default-shape turtles "car"
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9 @% K5 y% ~/ F# j" V if (num-cars > count roads)! B! ^, F% J6 T+ |
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user-message (word "There are too many cars for the amount of "
. X" t/ o2 b3 m "road. Either increase the amount of roads " \7 ^$ J5 j$ n6 u" T$ X1 `) c
"by increasing the GRID-SIZE-X or "( J- o8 z0 I2 t( b
"GRID-SIZE-Y sliders, or decrease the "
: u8 d& j7 o! q+ t "number of cars by lowering the NUMBER slider.\n"
0 H5 n! I: R6 |" \' f! J6 r "The setup has stopped.")4 L$ s. u3 i" r. }$ ?: W( f
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
5 ?! }. U! E5 c8 I; } crt num-cars
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setup-cars
) H7 F0 t- k. w" t# Z set-car-color+ S2 ` D6 d% l$ b$ j$ Z
record-data; P" I% S2 s$ `! {' G
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;; give the turtles an initial speed
5 H1 d% f# X4 q. y. r, ? ask turtles [ set-car-speed ]
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' X5 U8 r/ u' I: E; F: v reset-ticks8 B0 g0 E1 j+ ?6 [" S! v. @5 @
end
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;; Initialize the global variables to appropriate values( ?- W4 }. J; [' {3 e; C8 A9 n
to setup-globals
" t2 M" ^ c5 E c set current-light nobody ;; just for now, since there are no lights yet8 V$ G: I4 }0 o
set phase 0
M; a, ?6 T, S4 Y. N& q set num-cars-stopped 0
/ E$ S+ r0 v; k set grid-x-inc world-width / grid-size-x
, G! P3 Y" ^( n( F+ ^) I- h5 C set grid-y-inc world-height / grid-size-y
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( l% D8 K/ r* s. D' L4 } ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
* K9 N8 ?$ M; ]3 w7 \ set acceleration 0.099
& Z( H/ {/ v" V' A4 B( Q% `# T# Iend' ~" l; ]% ~' F4 N( ?& W
6 y. l, d: Y: _- I4 ^9 W2 B3 d;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
3 o) J/ O1 }6 X* w% f;; and initialize the traffic lights to one setting( {3 ~7 U- M; x4 o) {$ Q
to setup-patches
! F- p& c; F3 x% e ;; initialize the patch-owned variables and color the patches to a base-color1 ^& B g6 w: S ~ S( e3 W
ask patches
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# r" U3 e* N' b/ X set intersection? false; L6 q: [' Y! h" U5 e- G7 r
set auto? false% U4 O) N) d. h0 ~6 D
set green-light-up? true
6 R) j) R+ E: p' E$ |, w" c set my-row -1& G L0 z U, o: y" N
set my-column -1
! l7 c* y$ B7 \ set my-phase -1
5 s) \* J' a' ]) g- W u set pcolor brown + 3 p2 S# D' C! d0 z% l+ i: |) n
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, _$ S8 \3 r& z! N) ~. h ;; initialize the global variables that hold patch agentsets
- y) {' D! B G8 h* L set roads patches with
7 e; }' |1 Z% ^, h [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or6 k8 g, o6 a Y2 g2 p! _
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 I1 E& K" o# {! G1 ?: K. }- a set intersections roads with* P6 i; R; v, A
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
% [$ r; ^* w& z: E. S+ i+ k1 D8 M (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]6 a) ~! d5 w' A) e
setup-intersections7 d. u+ I" N1 Y( j1 |/ i1 ?
end$ n! m. v6 T/ c
其中定义道路的句子,如下所示,是什么意思啊?
5 Y0 p+ Z/ ?$ h8 X6 I: ?+ R: t set roads patches with
4 W- T0 R+ x5 t$ P [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or. b9 g7 a6 m! d- O1 ~
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 i# H& K \# Z |! Z* V8 A4 X: l( x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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