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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。
7 a( N5 F; l! j& onetlogo自带的social science--traffic grid这一例子当中,3 p X& J2 o6 G
globals
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! ? s+ a: x4 h% Z# [& \ K grid-x-inc ;; the amount of patches in between two roads in the x direction3 S$ x# n4 X8 b; N2 r) w
grid-y-inc ;; the amount of patches in between two roads in the y direction
( H5 ]5 P* l) ?, c- V/ j acceleration ;; the constant that controls how much a car speeds up or slows down by if" y7 m& L1 t% S E3 ^
;; it is to accelerate or decelerate. e! N# L* R' E
phase ;; keeps track of the phase
' U' y* S3 C* m, t% U) O) y num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
/ {" r6 g: A3 Y6 i y( l9 ? current-light ;; the currently selected light1 ^8 ^2 `/ o0 m0 {$ {, K
( m& @% O' |4 f/ [ ;; patch agentsets2 C; O% y3 G+ r5 m0 c' n# [! ^
intersections ;; agentset containing the patches that are intersections0 i$ V$ b* s- D- t+ S
roads ;; agentset containing the patches that are roads* `* @( x% @% ?3 [. t
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turtles-own
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speed ;; the speed of the turtle% v# u6 B( i7 M7 |' a( u
up-car? ;; true if the turtle moves downwards and false if it moves to the right
4 ^7 i0 }; O. g& o# r wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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6 h9 }! q/ b6 ` intersection? ;; true if the patch is at the intersection of two roads
6 U2 S, ^0 o) W4 j9 o green-light-up? ;; true if the green light is above the intersection. otherwise, false.
9 T T( c1 w/ i ;; false for a non-intersection patches.9 ?$ n; ~. a, W4 Y- Y$ I2 P
my-row ;; the row of the intersection counting from the upper left corner of the4 P9 J+ |- x% r g7 j& W5 ]4 B
;; world. -1 for non-intersection patches.
, |0 n! X8 Z5 ^ B my-column ;; the column of the intersection counting from the upper left corner of the
2 X/ C9 m" S$ I4 n- W$ w1 Q( D: _ ;; world. -1 for non-intersection patches.
4 p1 d4 G" X$ g- W) e my-phase ;; the phase for the intersection. -1 for non-intersection patches.
- f$ P/ {" W4 N @1 I auto? ;; whether or not this intersection will switch automatically.$ Y! K$ r2 Y% ?. E2 u
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
7 n/ @1 }* y: t, w* l4 ~0 k/ r' f;; Setup Procedures ;;
/ b! p6 |# I: n9 E$ r3 \;;;;;;;;;;;;;;;;;;;;;;2 \6 ~: ~- g9 \! {: R: w+ a
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;; Initialize the display by giving the global and patch variables initial values.
- B( m( c# |) U: t. ~8 D) Y' D& G;; Create num-cars of turtles if there are enough road patches for one turtle to
4 C) E4 Y. V" y9 B7 G" t$ |;; be created per road patch. Set up the plots.
, o% Q% j5 D7 z+ r: [9 i7 @5 H3 Uto setup
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2 Q5 s3 t; V$ [3 W o! p$ O- ` setup-globals
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. z% T$ D" F1 O1 U; { ;; First we ask the patches to draw themselves and set up a few variables
% j& q6 X1 K" i! R6 K( v setup-patches
+ t0 U, J% m% C3 H! t+ R+ e make-current one-of intersections
1 x; F; {( G9 Q3 {* A" }) M2 X: f- u0 l label-current+ _! Y' s( u( |1 w% _5 |: F" H
{$ E' N5 n" T8 X% c, f8 b0 D set-default-shape turtles "car"
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5 M( K( ]$ Y2 x$ O3 ~, X if (num-cars > count roads)8 h1 F% ]* i8 C' {! E* U
[
6 }5 q: F9 Z* V/ q+ ]; Q user-message (word "There are too many cars for the amount of "8 n- X7 q: u1 l( X
"road. Either increase the amount of roads "
& U# [0 m9 | { "by increasing the GRID-SIZE-X or "
0 X/ ^& f) Z0 r "GRID-SIZE-Y sliders, or decrease the "
4 Z" X) @' m/ V7 C* l1 c "number of cars by lowering the NUMBER slider.\n"* D5 u" n/ { H& M7 x
"The setup has stopped.")
! T! m0 G& N3 O0 {0 S! i- K stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
' O& H, K0 |, [4 j. ^' ^- m# a7 V crt num-cars: }/ J5 k3 r5 w/ r
[
" Z) u* b1 o# Z! h$ `% H" }- c setup-cars
]$ W7 w* ^; g3 Q( K set-car-color% o3 m+ S; q8 r, l0 K3 E
record-data
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2 g1 x9 ?; m3 b* U ;; give the turtles an initial speed' X/ a) Q+ j3 W G# `
ask turtles [ set-car-speed ]- v9 ~4 ~+ t% K- i/ c6 F: W
7 t; w: {) [' m reset-ticks, g# h6 J1 b, q( q
end6 ?: l& D0 ]3 [/ t' E- ~* I) `5 u
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;; Initialize the global variables to appropriate values" q8 @$ R+ v a! {
to setup-globals
% j; c2 s& @4 J% N& i set current-light nobody ;; just for now, since there are no lights yet' G" N+ k: A/ {0 \4 ?& z
set phase 02 P% e$ N5 T" y7 h4 B2 }
set num-cars-stopped 0
/ b4 l8 h$ l! D' r set grid-x-inc world-width / grid-size-x
! W& \: f0 s2 @. H9 R( I' G set grid-y-inc world-height / grid-size-y7 b5 W. x* C# y- {
" F" i# k$ B- A% ^* ? ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary- S: H9 }3 G ~6 d2 A8 p5 \
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
. t* m; v3 E4 Q6 I;; and initialize the traffic lights to one setting
" M5 o' c& j/ {to setup-patches
9 h5 g$ x q! }1 `. n5 e ;; initialize the patch-owned variables and color the patches to a base-color
. ?8 O6 z+ Q" Y ask patches6 T3 D' i& _( [, G0 U/ e
[
7 f2 |3 o0 a! J# j set intersection? false, x: [" L6 D8 w
set auto? false1 H1 I0 h I9 v& B
set green-light-up? true
, r0 D% ~/ T$ K( P& A1 w set my-row -1
4 P4 S1 ]1 J7 @- V set my-column -1
+ A, \( R/ y: {6 F set my-phase -1
! f$ Y+ G* @" G1 `4 J- u set pcolor brown + 3/ t" y: @# y) I4 _# c* _
]
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;; initialize the global variables that hold patch agentsets1 u/ h7 R: Q4 Z* d; k+ o
set roads patches with3 X% J; T) _$ Z5 G& L
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
; C+ Y4 H' o2 `1 ^* g (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
0 B: Z) P; n3 m% _" m; S set intersections roads with
" @) ~) L+ K( b }8 @ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
9 Z& C: I" ^- h3 v; J% I& { (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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' r5 o( X7 a( A$ `. L4 j( n, A( `' U ask roads [ set pcolor white ]
) {$ ]& x- F& Q" I, Z/ j setup-intersections
, P8 Q. k1 s3 @end
* o( m+ n7 u0 `, d其中定义道路的句子,如下所示,是什么意思啊?
8 G: B! w1 b7 r set roads patches with, n8 h6 A6 J4 E6 f: s# A) U
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or5 @: _$ F6 P6 v% k _
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]: C& \1 @2 h# u+ j. ~7 P* @! 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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