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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。! y- |# ?% t* P: r
netlogo自带的social science--traffic grid这一例子当中,
9 I9 F7 i0 g& mglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction5 C8 u3 t4 }9 {. Q3 l
grid-y-inc ;; the amount of patches in between two roads in the y direction
/ S2 m2 \* X: g7 H; N acceleration ;; the constant that controls how much a car speeds up or slows down by if4 h& }- b) K* d& B7 P. ]
;; it is to accelerate or decelerate9 T8 U3 L# m9 @: T
phase ;; keeps track of the phase
1 d$ I7 h, f6 r& a% v4 N2 | num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
+ w$ I% y! N/ l g$ M current-light ;; the currently selected light( \' D2 ? L' [! e, b& @$ v
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;; patch agentsets) [2 ^4 v& h/ {* \* V/ e
intersections ;; agentset containing the patches that are intersections. G, _- j: r$ e9 k# y
roads ;; agentset containing the patches that are roads: K% _% e4 \3 O/ ~8 d. {8 i& c% F
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9 U8 u* n' N1 jturtles-own1 K Y1 W9 s0 ]
[
' q5 `: f% Q6 m8 k( w* B speed ;; the speed of the turtle
' S+ x8 ?) W4 y) c. U* s9 I up-car? ;; true if the turtle moves downwards and false if it moves to the right
4 Q' s2 i2 Y7 a2 p \5 P wait-time ;; the amount of time since the last time a turtle has moved7 @/ m; P1 P l Q2 x! p v
]
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1 i- W+ H" C, ~& w5 ]5 v J$ @patches-own H* _. Q* O: e; `( _) i" F0 Y
[
6 `0 R8 H+ j" s+ f1 L intersection? ;; true if the patch is at the intersection of two roads
7 |2 A) L& U4 ^2 b I* r$ Q+ t green-light-up? ;; true if the green light is above the intersection. otherwise, false.
6 @4 U/ [4 p) y+ m ;; false for a non-intersection patches.
% |( i Y+ s$ Y* b* N' _4 B% Y my-row ;; the row of the intersection counting from the upper left corner of the9 H" I3 f& e# L4 M/ A0 @0 N( \
;; world. -1 for non-intersection patches.
$ v l! u; b1 z5 B+ ^2 w5 o# } my-column ;; the column of the intersection counting from the upper left corner of the
8 r2 \* v3 x3 v0 U ;; world. -1 for non-intersection patches.
& z1 r+ }/ H9 r: v$ x/ d% T my-phase ;; the phase for the intersection. -1 for non-intersection patches.
8 s7 j6 a0 z* Z auto? ;; whether or not this intersection will switch automatically.( R# D' Z, g" x; I$ L9 h% ?: q; m
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
) P k# W& Y/ @$ J) \;; Setup Procedures ;;
: B- f) ^. x, y% x$ Q;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.& X7 I! a0 ^8 e/ ~9 A
;; Create num-cars of turtles if there are enough road patches for one turtle to! c; G: x. M+ s# F6 d
;; be created per road patch. Set up the plots.
8 i. I6 l6 }1 ^# h7 k% eto setup7 }& U- j i* ^" e4 G$ }) M- R, {) {
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setup-globals8 q% `& u" J6 Y0 b" {. p. ~. O% n; w
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;; First we ask the patches to draw themselves and set up a few variables. v- }+ O7 w6 h
setup-patches
$ ? q$ T7 ]' |' m Z3 [3 ~' T3 K make-current one-of intersections
\; e' q8 ?- m5 g: e' y! a' C label-current6 _5 y/ S+ B' l1 a( t K7 ]
+ P- S) M' G# r& |/ L set-default-shape turtles "car"2 n' G) e: T' w% |
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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 "# S; Q) E8 U2 P4 s
"road. Either increase the amount of roads "
2 V; o' e6 j7 M, F C9 u9 \ "by increasing the GRID-SIZE-X or "
$ j1 Z& J6 C+ m% v% J ^' z2 C "GRID-SIZE-Y sliders, or decrease the "7 [0 {; a$ h" j4 y/ x1 d
"number of cars by lowering the NUMBER slider.\n"
; R; p5 Z4 m: K9 @! c4 S/ ` "The setup has stopped.")2 W2 w) P2 O; m( _5 Z
stop
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" |$ {8 c* |$ q' F ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color+ y5 b' |: r' n
crt num-cars
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7 n4 u. M- f B' v9 _ setup-cars& T# i9 T* q- ]
set-car-color0 s; l1 J z" ?* m7 k9 @; Z
record-data
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4 \4 w2 b& C' t8 C- D8 t# ^ ;; give the turtles an initial speed Y" J! @% l6 A- l7 e! t' ~5 w8 A
ask turtles [ set-car-speed ]% a- _/ q" a+ b3 K2 A+ R
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reset-ticks9 k; A4 m, O1 t1 s
end; a. U; L. m. T- _2 l
( H+ ~( s3 X; m& l# C! Z2 k;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet! f* o9 A+ B. }+ U
set phase 0
7 i! o G' a/ ~' `6 e2 p set num-cars-stopped 0+ V$ `# B% @/ u; X$ T
set grid-x-inc world-width / grid-size-x
7 n0 }: d5 w* Z, O! Q set grid-y-inc world-height / grid-size-y
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3 Q6 y3 y5 D) i k) o) Q# j ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
9 A6 a* V1 S3 I5 t1 E set acceleration 0.099
' V' A' e+ o8 _: |end( }% Y# V5 |4 ?, T
; ]; ^' [4 p' r, w4 K+ A0 D;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
1 {/ N2 @- c# e A;; and initialize the traffic lights to one setting, K' }/ L$ z% p4 ?
to setup-patches* Q8 Q |/ z. B: p% x' V
;; initialize the patch-owned variables and color the patches to a base-color( d5 f' L9 b% X$ y
ask patches
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set intersection? false
- _5 P6 `. b6 C/ X" Y0 A9 b6 y set auto? false
4 Z8 l) G E+ ~1 [; n: a0 y; h set green-light-up? true% y8 O. D+ t; ~5 z0 C
set my-row -1
- u* V3 h+ [* l* G set my-column -1- T6 s. V! N4 B
set my-phase -1( @% @! D9 M( i4 j# \! V# }0 ~
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets7 g/ m" D+ [) C' r" d9 t
set roads patches with2 i9 r' Z+ w& ^# `' X8 n
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
, Z' z- I/ U0 t/ [ G% M( O9 l (floor((pycor + max-pycor) mod grid-y-inc) = 0)]: J! c o5 k q: t/ F, i
set intersections roads with' x- l& x S5 v$ L! g" L4 q
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
$ y8 i" `$ {* C1 c7 M (floor((pycor + max-pycor) mod grid-y-inc) = 0)]. j: Y0 W r) B4 {( w4 E5 x1 e6 H
' Y9 f6 ^; M) T2 N5 m ask roads [ set pcolor white ]* v* o, t6 t" l
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?- @4 E( ?7 i+ R1 f& d P
set roads patches with( X" g& l# j8 i% s* X
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" ^- D3 ~ j" I: f9 Y1 D+ O (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 h7 ^3 [3 I2 l8 f4 N* `) e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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