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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。
/ r- @7 G% r* L( a3 ~+ Tnetlogo自带的social science--traffic grid这一例子当中,
g) f! s! O) q. N$ a, hglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
$ n* M: n8 D: b# ? o& E8 A/ S grid-y-inc ;; the amount of patches in between two roads in the y direction
( w- d* @3 q4 X# L acceleration ;; the constant that controls how much a car speeds up or slows down by if; U9 t* @: B% m
;; it is to accelerate or decelerate
2 Y0 V( p1 K9 c0 d: S% h2 X+ U$ R phase ;; keeps track of the phase
& C5 a7 z8 o1 I1 n4 q num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
9 H8 Z" s; n4 n2 ~( X! [- F/ C" D current-light ;; the currently selected light
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;; patch agentsets* b' @* i1 B" K
intersections ;; agentset containing the patches that are intersections S0 P( D( N) G0 S
roads ;; agentset containing the patches that are roads3 t' |7 k+ d; }6 a/ O/ O# `/ U3 T
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turtles-own
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speed ;; the speed of the turtle
7 k% d* ?+ ^1 y8 r) w up-car? ;; true if the turtle moves downwards and false if it moves to the right
, S* l9 P1 H! r7 W3 }- g$ g wait-time ;; the amount of time since the last time a turtle has moved; ]2 t7 J* g$ m! j; ?
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/ u; D$ x3 p; j5 `patches-own4 L4 {4 D1 O. m2 N
[
# v `& l4 X, k) b: D intersection? ;; true if the patch is at the intersection of two roads! o0 x0 P! S+ U. b0 k/ x
green-light-up? ;; true if the green light is above the intersection. otherwise, false.& {6 x* `( l2 [( g
;; false for a non-intersection patches. m7 i6 H; Y( B! K4 n7 |
my-row ;; the row of the intersection counting from the upper left corner of the4 |( a1 `+ _* ~% B
;; world. -1 for non-intersection patches.
. E% y B0 ~% r0 V& [) s. [ my-column ;; the column of the intersection counting from the upper left corner of the
d7 s0 P7 k, d ;; world. -1 for non-intersection patches.
+ ^( d- o! R- D1 Z A w* G my-phase ;; the phase for the intersection. -1 for non-intersection patches./ ~( G: P9 k N5 }/ j
auto? ;; whether or not this intersection will switch automatically.
- r- X) t6 w" O* [ ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
* L7 N) g2 W4 P$ A8 |. ]3 J;; Setup Procedures ;;( ?2 D% }& V9 Y7 [1 S+ j
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
, [$ t+ \* \& e$ N0 p;; Create num-cars of turtles if there are enough road patches for one turtle to$ v m) _& [! Z+ X' W& ]; o
;; be created per road patch. Set up the plots.
& [+ P1 C4 P1 e6 o% g( uto setup- T% Z4 ^. _2 C/ H I
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setup-globals4 J2 C6 i5 l# I+ ^# E" P3 C
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;; First we ask the patches to draw themselves and set up a few variables
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make-current one-of intersections
/ e0 Y% X g& Y8 u5 j$ U' X label-current
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6 u5 d% q3 j" J; z5 U! R! J set-default-shape turtles "car"3 W$ J# Y* D: y8 Y
2 a4 E8 k& ^/ p8 _ if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "/ i- v* N* K" X7 v7 K
"road. Either increase the amount of roads "4 ~1 N7 r1 O7 z/ x, Y: v
"by increasing the GRID-SIZE-X or "
4 P& v8 U0 Z9 ]1 t! L: q3 r "GRID-SIZE-Y sliders, or decrease the "
8 Z2 _) Y2 g u* z "number of cars by lowering the NUMBER slider.\n"
$ |* |% u3 r& _ "The setup has stopped.")6 X& J- V1 ~. n0 _- L* E8 O
stop3 ~' ]" J/ b9 G% Y" P1 P4 k! }4 g! {
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, K. J( i, f; Q ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
5 l# f; v; o0 u crt num-cars& ?8 i3 e/ G" u$ }2 }& r) J* k
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setup-cars4 {$ W% g0 n+ c" Q
set-car-color
; r# [$ T3 U: W& q+ o3 ] record-data
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;; give the turtles an initial speed
1 V% e2 P3 k: n ^ M$ a ask turtles [ set-car-speed ]
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$ w$ `' S* a$ T3 j reset-ticks: c/ z1 H& P, l( w2 @6 P r
end
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8 o2 J8 L8 o! b; v1 f7 e6 J7 d! K5 Y2 l2 m;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet' d4 H E. a, m4 `3 c. p
set phase 00 s$ s! v: q4 |3 \
set num-cars-stopped 0
) @2 F2 V: i1 K set grid-x-inc world-width / grid-size-x
5 q+ T4 g |( o0 ~3 U set grid-y-inc world-height / grid-size-y
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+ {4 q+ y" ]3 \ ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
- T% A$ l l5 e8 H9 X# t* s set acceleration 0.099
5 q1 H( c, R. a' n3 Cend! z0 u7 ^1 Y- l5 S3 T
) I( n( w9 x2 y' w4 T& F;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
6 _5 {! |" M) R- n1 _5 O3 A. @$ b/ ?;; and initialize the traffic lights to one setting" o5 a9 l( P/ \. b3 N
to setup-patches
# z0 {* c- Z4 y' o5 ~7 w, R ;; initialize the patch-owned variables and color the patches to a base-color7 E4 W( j- P. V! M( j' h
ask patches
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8 F5 a$ G, A3 V4 e$ A2 ] set intersection? false4 n* Y7 X) h" n+ l
set auto? false
% l; Z2 Q6 S2 o! h2 c set green-light-up? true, E9 n2 |7 o7 W7 A, ?8 O0 X& ^) T
set my-row -18 y8 k! s9 b( k& y( b7 u
set my-column -1
# H7 U4 D: r$ ^) R1 X$ e set my-phase -1$ G1 Y* i/ E2 h& E
set pcolor brown + 3
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7 B2 u1 @/ `8 {, |6 W! L2 C ;; initialize the global variables that hold patch agentsets
' w4 F: I" m- [$ w9 }4 b0 B set roads patches with }7 F+ ~" H* G, L1 e
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or W- s# n/ }+ u; w, P" x* z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
F0 H* z3 y5 }3 d @ set intersections roads with
& `8 i6 N. }: }# @- a6 W [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and# y* S6 ~' m+ b+ q+ ?7 f% t6 L" |+ R
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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( y, \; U3 a9 I d: n ask roads [ set pcolor white ]6 M0 O/ e5 c- ]/ V4 Q3 M3 o5 W# r
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?
5 }$ w9 ?- n! `8 x: L. o set roads patches with; l& {/ d4 M' P6 s8 E
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 D: V/ N8 X; y' Y* r/ z (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. M2 V$ `' L- ^3 L! G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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