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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。/ l3 \- r* }' k, Y/ H0 D3 [
netlogo自带的social science--traffic grid这一例子当中,; @0 ?& G7 N' y, P) r9 k k e
globals
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! q" b4 v$ {1 {( r2 c- t grid-x-inc ;; the amount of patches in between two roads in the x direction2 c3 i Z- r6 r. j# Q
grid-y-inc ;; the amount of patches in between two roads in the y direction
[- @( m" H* E# F acceleration ;; the constant that controls how much a car speeds up or slows down by if
; g1 l& e# R# R4 V# Q' E" j, W7 c, f; } ;; it is to accelerate or decelerate- F7 f1 }9 q8 [( Z
phase ;; keeps track of the phase
+ W" K4 Y+ u& q: Y num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure7 P3 V) c' a" \/ X3 g( s: P
current-light ;; the currently selected light
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;; patch agentsets: p# N4 U H* M9 R3 S5 b8 y1 `
intersections ;; agentset containing the patches that are intersections
$ k# `) o+ L6 G( x roads ;; agentset containing the patches that are roads- q! n0 A4 h r3 v! \
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turtles-own3 _3 t# n% K) Y
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speed ;; the speed of the turtle
9 s# I3 F7 b, p; I: n up-car? ;; true if the turtle moves downwards and false if it moves to the right0 ?* m, |" o8 ^; P/ a
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own# v" \+ @, l- g1 p& H
[
8 M) D+ B+ X& n% L intersection? ;; true if the patch is at the intersection of two roads
7 c5 y, A! p6 R G9 a% D/ ` green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! A9 L1 Q& ~5 Y4 A( u$ z! |- ] ;; false for a non-intersection patches.1 X' F8 ]5 A; P" U$ A& d) i2 M" d
my-row ;; the row of the intersection counting from the upper left corner of the
" H) Z8 a/ e% [ ;; world. -1 for non-intersection patches.
) S& L' B7 i( \) j0 w. L8 n( { my-column ;; the column of the intersection counting from the upper left corner of the
+ T, [' W4 {( N% d6 q& }, Y ;; world. -1 for non-intersection patches.+ ?. s4 a0 U, K3 _4 k- Z/ Y9 Z
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
6 r r' s& u, M8 m7 p' Z; O auto? ;; whether or not this intersection will switch automatically.2 r- l f* i' w6 E! O
;; false for non-intersection patches.- g3 W4 Y. h& I- M5 m4 p" d) U( D
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" @% G: w9 S6 i) v;;;;;;;;;;;;;;;;;;;;;;/ ^/ S6 ]5 X2 [3 D# S, j
;; Setup Procedures ;;
* ]$ q2 ^' | l4 W6 b4 i;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
! r) U; q5 a T G: { z& b$ M& w& M;; Create num-cars of turtles if there are enough road patches for one turtle to
0 f0 h( [, E1 a) F;; be created per road patch. Set up the plots.
9 c, P6 }6 l- o6 v) uto setup2 w, I8 R2 l& Q+ W; E i
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setup-globals7 _8 P, }) U) J1 {+ D
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;; First we ask the patches to draw themselves and set up a few variables% u( U) r. ^" m( x- X
setup-patches. T& N8 U2 a& L' z5 O9 q+ w( ~% L
make-current one-of intersections" q( ]3 l6 u' S1 i; Q0 A) s
label-current7 ^% _( v8 h( L1 C+ s; m
1 Z- l( z+ B% Y: |! H; t/ c x' h set-default-shape turtles "car"" `: `# ^' M5 l/ F) j: S
% @" t ]6 j- Y3 |9 _2 Z2 U if (num-cars > count roads)5 }. Y9 _& {; `) {
[
! Z1 W" K, a( } user-message (word "There are too many cars for the amount of "
" ]+ t K7 p0 M+ [% a "road. Either increase the amount of roads "
; j! Z/ ^+ K8 N3 Q) u M" J. l o Z "by increasing the GRID-SIZE-X or "
; r1 m) ]# n7 f, l; Z9 Z5 v "GRID-SIZE-Y sliders, or decrease the "
' S, P; L1 B, Y W% P "number of cars by lowering the NUMBER slider.\n"
9 e! g0 Y6 _8 _- p. Z+ X# N5 G) Y "The setup has stopped.")1 S: S- g! |8 }( M4 W, a
stop
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}- `2 B+ h7 g P ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color/ `) c8 \! q+ v6 j% E
crt num-cars6 }* t/ m1 R' ]1 g% a
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setup-cars) g E! ?- b- [/ ?
set-car-color6 X b# `! w q& P. U
record-data: i4 R+ u+ n" ^2 ?
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- d1 ?# ]- q# T8 P5 X5 Y" M ;; give the turtles an initial speed
4 c: y; \( }, u$ _( X Q& d# r X0 ]6 I ask turtles [ set-car-speed ]
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reset-ticks
% Y; ?1 i0 H. q' [0 v: n B' Pend
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9 d8 T$ B! e) F( B0 Y;; Initialize the global variables to appropriate values
+ ^0 j$ u% o5 d$ Wto setup-globals9 i2 \- K: D: k$ t8 X
set current-light nobody ;; just for now, since there are no lights yet
# D4 s/ J: @6 S: ]( K set phase 0
" J7 F: I5 f% T/ F, }8 F/ t% P set num-cars-stopped 0
% v- w1 b! _) k2 Q. x$ r set grid-x-inc world-width / grid-size-x
' H! T3 R V1 L" D6 K1 h$ l( u set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
6 q* w+ c# ` L$ N) E& U set acceleration 0.099$ X; P! L3 c9 Z8 e2 ?9 T3 F
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,: m( p. c- V% \, s' {. H2 w
;; and initialize the traffic lights to one setting; y; g* Z4 e E+ _4 d9 _) s
to setup-patches
6 Q9 D* o' O1 U) m6 d* u( m) A ;; initialize the patch-owned variables and color the patches to a base-color
& [! [1 t2 g7 d0 `3 r ask patches
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% X' p$ t+ u8 d/ v2 O, K' \ Y4 S set intersection? false
9 C. d1 i" A) |- u5 Z' N! E set auto? false* c" k+ V4 v) H/ `
set green-light-up? true/ _- L: T/ [3 \
set my-row -1
; e; t0 Q: a5 f4 r set my-column -14 f! U8 [) c) i/ c6 y
set my-phase -18 j. Z2 }1 t# Y
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
% h; }5 ]! O8 D set roads patches with* J. {9 |& B0 H- m3 s( L
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or/ T' q7 U4 e; d$ w `$ D( R) x
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
$ R$ k1 V. W! b# i8 r4 m0 a1 l8 o set intersections roads with/ e2 m8 V. z6 U+ K
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
) U, N( m% r6 L* l2 g. t (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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. E9 T; V0 T7 S! Q; h( B ask roads [ set pcolor white ]
! m1 C8 r- G* `$ ]0 a setup-intersections9 A4 [+ l2 T) U2 J
end
0 ], x, a3 |) E9 H" F3 L其中定义道路的句子,如下所示,是什么意思啊?
* i: L0 M+ g; T$ l8 B7 c set roads patches with
% ?! E& @! x2 C2 g [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
+ F ?. \! ?% X1 [ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
) V* h% S, n( T) P% G, 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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