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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。: I' [) J( `& u. f4 H
netlogo自带的social science--traffic grid这一例子当中,
$ Q' C2 h! d; j' y8 hglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
; ` I, ? L. c) J. q grid-y-inc ;; the amount of patches in between two roads in the y direction
# E: e6 R$ q* J acceleration ;; the constant that controls how much a car speeds up or slows down by if# d3 F. m) }2 a3 y" {( _7 m
;; it is to accelerate or decelerate
% n5 \; M. v+ M: p phase ;; keeps track of the phase
# Y$ {6 `7 Y o$ N4 f2 K" _; ]- L num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
& [4 E: m% {) s- K1 ~# O" d X current-light ;; the currently selected light
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;; patch agentsets# u# I0 A+ l- j
intersections ;; agentset containing the patches that are intersections f1 z0 n; u4 F" U$ k
roads ;; agentset containing the patches that are roads: D7 _8 P" J& D1 L* u3 a1 Z
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$ O+ V9 j7 h4 Y7 }: h% w/ ~turtles-own: @) q4 F6 a8 Y/ \* R/ |
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speed ;; the speed of the turtle3 j2 p, A, D7 I. q4 t4 R
up-car? ;; true if the turtle moves downwards and false if it moves to the right' w0 f4 m$ y+ P' M0 |
wait-time ;; the amount of time since the last time a turtle has moved% s* K" s L7 V
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patches-own
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$ ?& Q8 V( y3 X# C9 k# } intersection? ;; true if the patch is at the intersection of two roads: ?. f3 `% ~! y
green-light-up? ;; true if the green light is above the intersection. otherwise, false.; w; D' c3 J, r' G
;; false for a non-intersection patches.; s' o$ {$ H3 r4 m" J/ |
my-row ;; the row of the intersection counting from the upper left corner of the
2 M) B, H q$ c; K z ;; world. -1 for non-intersection patches.6 P" V' {1 {0 B
my-column ;; the column of the intersection counting from the upper left corner of the
) J% c, ]' C' n7 q3 \3 N ;; world. -1 for non-intersection patches.
7 h! t- |& z( M' h8 K my-phase ;; the phase for the intersection. -1 for non-intersection patches.
1 \$ \+ E& W/ ^3 B3 o% u8 h auto? ;; whether or not this intersection will switch automatically.) J/ a3 ~. ~. U5 X" V8 X' D! p
;; false for non-intersection patches.
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( [6 O3 l8 t/ ~$ Y; W7 u;;;;;;;;;;;;;;;;;;;;;;
& o- S. p5 y* y& S8 x;; Setup Procedures ;;; b" L: L/ p- E ?
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0 n. ?* r' D! C& [;; Initialize the display by giving the global and patch variables initial values.
. C6 X+ m7 Y& {, M, {2 ~;; Create num-cars of turtles if there are enough road patches for one turtle to) r5 x! i3 u j6 ^1 b4 R+ q
;; be created per road patch. Set up the plots.
/ z5 L8 a% p% ^0 t) }3 n6 pto setup
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& |7 Y. [ Y9 M7 @( c8 `6 [' h setup-globals
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;; First we ask the patches to draw themselves and set up a few variables3 j+ E* X( z6 D" L0 r/ |8 Y1 Z
setup-patches
0 a) \2 w0 r) i7 D% b, S make-current one-of intersections
9 d6 u2 c5 @6 d& k$ O G label-current7 ?6 M! ^: W" @# i, [$ S
4 C% `; B5 k( u0 f( J/ G& @ set-default-shape turtles "car"! G3 X5 h2 C& Z, [" b1 |2 y
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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 "
: ~) j5 z- a8 @9 | "road. Either increase the amount of roads "
& `4 {, C/ J: l: d: K4 e& d* y "by increasing the GRID-SIZE-X or "/ `# a) h% r( [/ x9 ]1 {
"GRID-SIZE-Y sliders, or decrease the "4 L" {0 H( Y4 b. @: M( {
"number of cars by lowering the NUMBER slider.\n"
2 H2 H, w6 e& }. O "The setup has stopped.")
# b L* f) j% J8 O) o) T stop/ H& r6 Y, S) I1 Y' { d
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
" v3 p/ C) ^4 A7 u% r `! H crt num-cars
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5 S, N; E) c* z4 d$ \$ g* B" N3 p setup-cars
. D- a- _4 |+ C% Y/ j set-car-color! v0 V; u8 Q# k. B6 y
record-data. ~' `1 x/ e/ L0 `
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1 [- `" `- c2 E( g& O9 U. [: ? ;; give the turtles an initial speed g1 e) C" |6 r% y- }) W) K( c
ask turtles [ set-car-speed ]( |" ?$ I* k) i
/ r! s! _! w3 x' L. @ reset-ticks
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;; Initialize the global variables to appropriate values0 Z0 g9 T: U! g( B. x1 t7 T
to setup-globals/ d. ^, i3 i3 C3 B F% `: `- s
set current-light nobody ;; just for now, since there are no lights yet
9 X% R3 {; V( p g& t( I$ j8 K set phase 0
$ A% b! k' t3 V9 z9 P set num-cars-stopped 02 b+ o; d) p/ b
set grid-x-inc world-width / grid-size-x
; g1 A" M% G2 S3 r set grid-y-inc world-height / grid-size-y
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. g+ P0 \9 ~* ` ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary: f h! ~* z- V0 P6 H; I! `- W$ i
set acceleration 0.099
+ N/ s: O5 N B1 N- q8 uend
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3 f+ I9 q# ^( S+ Z. X9 {;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
% N: V% ]8 c" B& d7 v9 e1 r;; and initialize the traffic lights to one setting4 V- d! C* l+ |% g _
to setup-patches. H6 N) H8 P3 D
;; initialize the patch-owned variables and color the patches to a base-color, S) G" W2 V; H/ k
ask patches0 E6 `* a! f Z+ I
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set intersection? false
! i0 @6 ^5 r5 m @" a1 \9 i$ i set auto? false a% w7 x* G; p: B) O% _# V
set green-light-up? true' v& ]6 M! B5 ]1 G% ^" c
set my-row -14 A! o8 R3 f3 k, m1 j
set my-column -1
9 ]: q* R5 X K! k8 i: T* W set my-phase -1
2 P+ b/ y* ?# ?0 i set pcolor brown + 3# C9 s& y; a* b/ D* x7 I
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9 B- S2 v+ i) \0 i8 ~ ;; initialize the global variables that hold patch agentsets
8 I4 \) u5 N8 x6 ]1 M* c) c0 j/ K set roads patches with
( B! C C$ J2 u: ?5 g) K [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 @, g+ b" ?% _- I0 M F/ W (floor((pycor + max-pycor) mod grid-y-inc) = 0)]& J: R4 o5 [7 g
set intersections roads with8 E/ X! U1 ^1 r
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
* h0 f& Q4 N% t8 v+ t) Z# Y% @+ d. o (floor((pycor + max-pycor) mod grid-y-inc) = 0)]- `5 z5 {% Y% b% F
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ask roads [ set pcolor white ]' s; b4 F9 Y# [% I3 X9 E, u9 o
setup-intersections
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! n( k3 \* y' Z8 G1 ?, O O# L其中定义道路的句子,如下所示,是什么意思啊?
4 i# ]" ^( b1 |( M) y9 `; C1 \# S set roads patches with
% l1 z5 c0 K6 p k; | [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or; ?$ z9 f- _3 k) T5 u& _. H) M
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 M" d+ s5 I: V1 R3 m8 C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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