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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。+ @0 v1 a; z, M
netlogo自带的social science--traffic grid这一例子当中,
' p+ I( q6 b" L, _globals, }9 T; y1 [9 A4 W) L" W
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grid-x-inc ;; the amount of patches in between two roads in the x direction! z/ B" w }# q8 h% C
grid-y-inc ;; the amount of patches in between two roads in the y direction: b6 Z, _( \+ b7 p; ]- j" m5 u- ^
acceleration ;; the constant that controls how much a car speeds up or slows down by if
' _4 h$ f: D2 R4 w ;; it is to accelerate or decelerate6 A& P3 J: N4 }! q& l" {
phase ;; keeps track of the phase% C$ p( U8 N( _/ l3 C, D
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
3 \8 J7 t* `2 }: m4 g current-light ;; the currently selected light. `, H" E! t* [- V- ]
$ P. M; }3 a: |2 I Q! b2 G/ t ;; patch agentsets
1 i! P. n- m& h) f* I# E+ |0 j intersections ;; agentset containing the patches that are intersections
; y9 l8 l+ z/ \! J4 Z B8 O roads ;; agentset containing the patches that are roads
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+ H+ D9 ]# o3 ^turtles-own0 }- ?( y8 Q9 V) `
[
, z/ s, T; I, ~; o+ k7 H/ T$ W speed ;; the speed of the turtle+ c& J' _8 }/ W' h) _* {5 h
up-car? ;; true if the turtle moves downwards and false if it moves to the right5 W8 Z; S7 j: ~) j: o- U* U4 y3 Z
wait-time ;; the amount of time since the last time a turtle has moved
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z5 M) g# d- qpatches-own
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/ W/ H% R4 P5 @$ A intersection? ;; true if the patch is at the intersection of two roads3 n2 j4 ?$ j5 Y! c0 k3 [6 v. S5 S3 j
green-light-up? ;; true if the green light is above the intersection. otherwise, false.0 Y" D+ W' L2 ?& J' C1 o: ]" v
;; false for a non-intersection patches.3 o, N* c( a; M- d+ U" k
my-row ;; the row of the intersection counting from the upper left corner of the
9 @8 R% t9 ^& I* _/ }, b ;; world. -1 for non-intersection patches.
3 j# g, u. Y/ W7 ]0 x8 u( u/ L my-column ;; the column of the intersection counting from the upper left corner of the
+ l6 `; b @! F2 h3 v. n; d ;; world. -1 for non-intersection patches.8 d4 M' V$ U8 i( Q5 }6 a# Z
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
" r3 O0 `0 x$ |1 q. n' ? auto? ;; whether or not this intersection will switch automatically.3 c7 J! F. G+ y) f
;; false for non-intersection patches.1 ?, e3 q$ @5 f3 |+ q
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;;;;;;;;;;;;;;;;;;;;;;
4 |+ q+ H# }" R- D;; Setup Procedures ;; x5 B8 d: ]' A% f4 R
;;;;;;;;;;;;;;;;;;;;;;- o, X- o4 P4 _; L% t) G
: T$ c% l+ s2 J; }- x& b" I7 P;; Initialize the display by giving the global and patch variables initial values.
7 K9 V& T; L, u9 `;; Create num-cars of turtles if there are enough road patches for one turtle to
) w# a4 Z* S1 L A+ k$ v/ P6 w;; be created per road patch. Set up the plots.1 x1 G5 z8 R v2 V3 p6 g1 J
to setup
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0 [8 O% x5 L: Q) y. Y setup-globals
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;; First we ask the patches to draw themselves and set up a few variables6 f, A. A5 H- T4 y" E/ T( J
setup-patches
! x& V. M1 p8 q0 U! K9 Z/ o! N make-current one-of intersections
, ~6 ]) U6 U6 ~' R0 v T* g label-current
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. {! r/ k3 B, H; T0 J, m6 c8 h set-default-shape turtles "car"
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
3 M6 d. F6 A3 K" o4 v7 J "road. Either increase the amount of roads "* ]. D, g# N. `' o
"by increasing the GRID-SIZE-X or "1 Y/ K$ \+ K6 `* ]' g
"GRID-SIZE-Y sliders, or decrease the "& L8 C$ y1 X# V) w; w# I
"number of cars by lowering the NUMBER slider.\n"% ^+ E* u9 \1 W2 Y/ g$ r, K
"The setup has stopped.")# P9 ~2 E, p, P, Y, F
stop1 @, \# h4 _4 u5 ^3 E- O! p
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
7 d% {- m- u3 \/ s crt num-cars5 T1 \3 b4 g9 C% {, L
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setup-cars3 ^4 j" a" I3 j1 n& Z
set-car-color
9 p) i' h! R4 ?) o! q record-data
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;; give the turtles an initial speed
4 b' G, ]3 Q% N/ m ask turtles [ set-car-speed ]
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reset-ticks
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5 }$ M% |# \6 z6 n2 |) ? u;; Initialize the global variables to appropriate values
J6 A& U9 b B7 Ato setup-globals' ~, j/ K' v2 a5 X9 J& U X$ ]
set current-light nobody ;; just for now, since there are no lights yet. ?. C1 Z# A1 y, B# q2 J
set phase 0
+ r* D7 X3 @7 {2 P* }8 A( t A4 N set num-cars-stopped 04 m7 I% Z O0 s/ [$ W5 R
set grid-x-inc world-width / grid-size-x
Z0 @+ L& i: c' a; C- [ set grid-y-inc world-height / grid-size-y) O2 V; ?; u+ I+ u: r+ q
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
, M/ I/ d3 \( v set acceleration 0.0998 g3 p8 U0 ^6 x, r
end
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# ?, v H2 `* I k' {;; Make the patches have appropriate colors, set up the roads and intersections agentsets,# E- T" P/ [; N/ U
;; and initialize the traffic lights to one setting' j, m" J6 [ ^9 e( }. S
to setup-patches+ T& n: j B( P
;; initialize the patch-owned variables and color the patches to a base-color' a) L, Y' }6 e4 k
ask patches) ]5 S1 H: i Y& V2 Y2 J, B
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8 o$ z$ L* B" ?- a/ F# i. G set intersection? false- @$ x0 E- ~% V& B% h( o
set auto? false/ n8 Z; p7 w$ T
set green-light-up? true
/ C8 f# v) s$ j set my-row -1
2 V7 {' n0 p8 q8 k- c6 T set my-column -1
, _9 H) k- @# ^4 s5 J set my-phase -14 S' a' u' ` f
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets: G- l" p8 ^! f: @: O: b
set roads patches with
; l6 r& `* s( t+ J/ u6 F [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
6 r, I; B5 z5 u( m6 g1 u4 ~5 |9 H& p& ? (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
p+ T+ O& o1 g set intersections roads with
3 U# s% u9 q) i9 ` G [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
6 S) a5 I1 _8 R, Q" t- z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 Y, U1 @" b% x# \7 o0 B
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ask roads [ set pcolor white ] q. J; x5 q# }( b+ k* t0 X
setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?
; \) e3 @: B7 E" I5 r set roads patches with4 a, S9 z' b$ z- e W
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 U. C" C. M8 q% l (floor((pycor + max-pycor) mod grid-y-inc) = 0)]% J# x7 { b0 n" i
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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