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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。6 k0 U: ] E! f( @; M
netlogo自带的social science--traffic grid这一例子当中,
3 c9 ~% p6 o2 ^1 \globals) |7 _6 @5 F( G! P
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+ `9 f: U- h4 @: x0 Y* C grid-x-inc ;; the amount of patches in between two roads in the x direction% {9 Y3 i7 q% X
grid-y-inc ;; the amount of patches in between two roads in the y direction' @! p1 M+ N: e' r H" [
acceleration ;; the constant that controls how much a car speeds up or slows down by if
8 _2 @5 Z1 D. `* I) Q ;; it is to accelerate or decelerate: k' S9 n" ^9 D6 r8 G5 ^
phase ;; keeps track of the phase
2 `5 x5 b5 O7 ~& o2 x num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure) y/ ~2 q" v3 `0 v/ S1 h
current-light ;; the currently selected light
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;; patch agentsets
: O- y& M I. C: @3 f7 X5 R intersections ;; agentset containing the patches that are intersections
+ B- M6 w2 i, g, h& f3 h roads ;; agentset containing the patches that are roads
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turtles-own) u, G( z" i$ z8 k6 V! V
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1 o% B+ ~ @8 U. e' r: P* t g speed ;; the speed of the turtle& Q) ]8 }7 Y: d1 U5 ?2 |0 l5 ]
up-car? ;; true if the turtle moves downwards and false if it moves to the right
" k7 A0 K( Z3 |+ u' A, i wait-time ;; the amount of time since the last time a turtle has moved
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- u/ S7 o) E6 f% e/ o9 L4 z, i8 ]$ Epatches-own
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4 d( U% Q: j, ^ \" V. S$ O intersection? ;; true if the patch is at the intersection of two roads8 ]: j4 N3 V# q
green-light-up? ;; true if the green light is above the intersection. otherwise, false. B' u6 X! j- l- Q
;; false for a non-intersection patches.8 F6 p( H4 z8 i1 ^, y+ F8 D# l
my-row ;; the row of the intersection counting from the upper left corner of the
6 N' S+ ?/ \" b9 b: R ;; world. -1 for non-intersection patches.( \. s0 J# Q6 q7 C2 [$ r" Q% b5 l
my-column ;; the column of the intersection counting from the upper left corner of the, ~" o+ l5 L$ L8 R ]
;; world. -1 for non-intersection patches.* F5 X D1 F c( {2 e5 W
my-phase ;; the phase for the intersection. -1 for non-intersection patches.4 h( K+ x: X. Y0 S
auto? ;; whether or not this intersection will switch automatically." \ p+ P# t6 Y) H2 G2 u
;; false for non-intersection patches.( B0 X7 M: \4 W, }6 s f
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;;;;;;;;;;;;;;;;;;;;;;+ o+ w7 [; [6 L; A2 b6 f
;; Setup Procedures ;;
7 _5 n+ |7 ~- G' g8 \; ^7 r2 m( p; H;;;;;;;;;;;;;;;;;;;;;;- R9 }$ Y9 J l7 k
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;; Initialize the display by giving the global and patch variables initial values.' P, h, j; y9 e3 h
;; Create num-cars of turtles if there are enough road patches for one turtle to3 Y- h( _$ U! x9 T' v; g1 f
;; be created per road patch. Set up the plots.
; n) c# p+ S5 W: x. xto setup* C# N. c- u9 n, `
ca
( W+ z, y/ E/ U0 i: }7 s setup-globals; O+ s( j1 W8 f+ m+ ~) C
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;; First we ask the patches to draw themselves and set up a few variables! m, w' Y, W# \ |" Z
setup-patches
, N0 s: ?: l) h8 z make-current one-of intersections- n m+ q# J( A
label-current
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* j% H2 @5 F C _7 p0 F- Q: K1 V: Z* V set-default-shape turtles "car"
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/ L# O2 Z4 I/ s. m( L+ @+ h% N if (num-cars > count roads). Y: V9 E# b& i8 u
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user-message (word "There are too many cars for the amount of ". Z6 K" r3 w$ Y' J4 S& H. {4 T% v
"road. Either increase the amount of roads ". [# W- p0 K/ f- ^& C- L4 d9 ?
"by increasing the GRID-SIZE-X or "
2 m6 I# U0 L" S; {- q "GRID-SIZE-Y sliders, or decrease the "
) m7 M. O4 E0 B2 m: j+ s "number of cars by lowering the NUMBER slider.\n"0 z1 Y; `& H" o) v, V2 N8 a
"The setup has stopped.")
. m/ q9 M' ]5 }* l9 p! ]9 [- Y stop, o# }. k2 r: ]
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- k ^% e9 ^9 j( h+ P3 T# {: }- F ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
7 {0 Y0 j3 s* a1 _/ I# q# m crt num-cars
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setup-cars! D, s0 r# Z3 o! u
set-car-color( d/ J/ W7 t4 Q( U1 |+ b: S
record-data
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{7 ]3 c* k* o5 ^ ;; give the turtles an initial speed
' ]" i: b) V8 W: d6 N ask turtles [ set-car-speed ]9 |9 l/ X. W) D, Z$ X, a
2 U, T, H4 H, q reset-ticks: |1 Y' e* W3 ~. u6 O
end
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;; Initialize the global variables to appropriate values
) Q6 x, l) V, N% Eto setup-globals( u, p# J. w1 {/ k0 @% a( q0 z
set current-light nobody ;; just for now, since there are no lights yet+ _$ r+ {& D) x
set phase 0( o1 @$ X: `9 n% N
set num-cars-stopped 0: g. i/ v T! {6 |! H
set grid-x-inc world-width / grid-size-x
$ @' U4 m. o% O$ F& T# v) b set grid-y-inc world-height / grid-size-y; B) x+ `! n! D
# L8 J4 q; M8 _3 x2 k2 w ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
9 s5 c: o* @3 t* W6 E% ^1 i set acceleration 0.099- B+ a6 g3 m3 c7 }' S* r" C
end9 o# Q1 w0 E. q1 d3 M* y' H
" l# v1 {# L/ B! F& k4 Y;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
6 w& a o5 H, y8 t( Y# q( I, K/ q3 o9 {;; and initialize the traffic lights to one setting
7 ~+ Q1 X3 p! _" S6 hto setup-patches7 _7 G5 c8 y0 L7 a
;; initialize the patch-owned variables and color the patches to a base-color7 [# U2 b4 U$ ^* q+ U% O
ask patches
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set intersection? false3 u+ C' S, }6 R- E) v7 E( o
set auto? false
6 l6 w+ o& b7 r/ j4 P! T set green-light-up? true# }! O0 l2 e0 Q
set my-row -1
6 i& I7 z! ~+ A* z set my-column -1) q6 h" ^) ]/ y p/ ~
set my-phase -1
! U0 ]5 }# F7 k! {& l+ z8 ?" S set pcolor brown + 32 Y; L; B. T5 G2 [
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/ v; [% P% G+ R- Y# R& | ;; initialize the global variables that hold patch agentsets
6 U7 n' f1 E) D- |7 M( j set roads patches with4 H% E. @5 f) ^7 z. v, D9 B5 G
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" T- g( g U8 M, c# X/ a (floor((pycor + max-pycor) mod grid-y-inc) = 0)]* \6 n* k$ |6 e: J4 Q
set intersections roads with+ ]% m( @8 \& f- \" V, e, Y, l
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and+ F7 ?2 z+ p. ?% X: Z- A P/ F* V- O
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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' E3 {8 d2 o# _) ~5 S3 z ask roads [ set pcolor white ]
* q6 c# R7 V2 n8 L% C" ~' c 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?
/ {' H4 |; C7 t; ] set roads patches with! S) @( w n' }1 D7 ~6 \
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) H) Y/ M" }5 I& r* R" O$ A4 o: N, N
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. i2 ^+ Y5 H8 x4 D" F7 e/ ?5 W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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