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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。
, p. ~, }6 ]& w. Unetlogo自带的social science--traffic grid这一例子当中,
U: _1 Y. z( o" q! k; m/ O. K8 zglobals. E7 {) j) n. v) a+ i* X
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grid-x-inc ;; the amount of patches in between two roads in the x direction- B& D8 \. T4 I6 ^6 M3 @9 s
grid-y-inc ;; the amount of patches in between two roads in the y direction
: M. E% }8 Z+ o: n; Y; l7 ~ acceleration ;; the constant that controls how much a car speeds up or slows down by if
, E& h/ ~5 o2 v5 V# F ;; it is to accelerate or decelerate, r5 ?" S h: D1 @1 N& A
phase ;; keeps track of the phase9 s! a! K6 D; Z+ U$ @# D
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure/ C" H2 e) p5 j: p
current-light ;; the currently selected light8 R% c% B. e- f0 `2 ^" P
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;; patch agentsets
9 m" B9 [) v7 c( ^; d$ g, A+ ` intersections ;; agentset containing the patches that are intersections
7 P1 K. W( k9 e5 r8 F! l0 K; k roads ;; agentset containing the patches that are roads! f/ ^2 d2 K: o/ T
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turtles-own
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speed ;; the speed of the turtle) M( a( q* x2 {2 k4 k9 P/ J% k! g
up-car? ;; true if the turtle moves downwards and false if it moves to the right0 ]0 U8 z3 |5 b9 Q
wait-time ;; the amount of time since the last time a turtle has moved% t9 \$ P6 J B0 o
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5 z) B! W" t M: {/ @patches-own
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; ?$ m- R6 Z! V- B; a intersection? ;; true if the patch is at the intersection of two roads
+ [9 G" i7 B% r! d6 g- b& V green-light-up? ;; true if the green light is above the intersection. otherwise, false.
+ S4 F# q3 Y1 u& C ;; false for a non-intersection patches.
7 k6 p' f( h2 r9 I5 t my-row ;; the row of the intersection counting from the upper left corner of the O7 C6 b" E; o8 N" k) W5 @+ x
;; world. -1 for non-intersection patches., ?* U9 m+ X7 n9 x
my-column ;; the column of the intersection counting from the upper left corner of the
: v$ e) ?1 j! C ;; world. -1 for non-intersection patches.1 n- {5 n" u& j8 v- e0 J5 j) m* y
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
/ v" J" Y/ J3 F$ R4 U auto? ;; whether or not this intersection will switch automatically.$ Z- S2 }* { M1 w( V3 G/ Q' h; R
;; false for non-intersection patches.+ h, N8 n$ u, A+ ~, Q
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+ j \+ K; V2 A5 k# s% z2 e;;;;;;;;;;;;;;;;;;;;;;+ p% i, B. u9 e8 |# |& S8 ]
;; Setup Procedures ;;
+ A' l8 J0 p2 F0 V& [;;;;;;;;;;;;;;;;;;;;;;' \& `/ f. @* F1 M A
/ `2 O: N2 k/ S! ^3 t. q;; Initialize the display by giving the global and patch variables initial values.
4 H, L9 f3 U7 R& ~- |;; Create num-cars of turtles if there are enough road patches for one turtle to
8 Y6 g& O' D& m3 s4 W( s) c;; be created per road patch. Set up the plots.
( l M) p3 s7 L ~1 ]to setup) ~, I, ?3 E; n: I/ \) U
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
8 \; _ o2 x8 N setup-patches2 ]& Y8 `% c- V% ?
make-current one-of intersections/ [! c$ [! E* W' i. n" w( o
label-current* N8 n. Y. A# x8 M+ q
6 ~( z7 g3 j$ b! Q set-default-shape turtles "car"
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if (num-cars > count roads)7 n( p' i( ?! R% T% P; K! G6 O3 X9 i) j0 b
[
+ F0 v, N! e" y" O user-message (word "There are too many cars for the amount of "% z3 D* ~. p, _$ J- q% |# I1 Q
"road. Either increase the amount of roads "0 q2 @7 i" Y/ n. p% ]5 S# U
"by increasing the GRID-SIZE-X or "
0 X$ s/ R) P- B0 v "GRID-SIZE-Y sliders, or decrease the "
! B# v/ i) v7 x) S "number of cars by lowering the NUMBER slider.\n"
6 J$ q; |7 P2 d- o" M2 o1 c "The setup has stopped.")% j7 h! Y7 F" n. N8 {' d. ]
stop; ?) I' Y5 o% {( x1 H- l# w) u( N% d
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- t" M: {$ Z+ m# ?- X ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
1 E3 I! B& L4 K0 \$ T/ a crt num-cars
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setup-cars$ z' f: d. F" x2 C) Z
set-car-color8 u6 G) E9 g6 V. C/ q V0 u
record-data
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! X& T: V3 g3 }$ t; c* m ;; give the turtles an initial speed
% z9 X1 w$ _& b ask turtles [ set-car-speed ]
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reset-ticks( o, ?( N- @9 a) U3 c- K1 K$ L" r) ~
end( `9 {# n* B7 A6 }6 y( U0 p
+ u" y: o0 }; J1 I;; Initialize the global variables to appropriate values) }" N. x; Z, l3 r. j$ r5 ~
to setup-globals
- V) k7 K2 a3 P5 O9 c; d1 p$ @/ m set current-light nobody ;; just for now, since there are no lights yet
! m. a4 G2 `1 ^$ }! ?" { set phase 0
7 k g) V* X+ N: n set num-cars-stopped 0- ?4 b1 X4 h4 b6 o4 `+ ^
set grid-x-inc world-width / grid-size-x
( T6 g4 ]$ l2 z7 { set grid-y-inc world-height / grid-size-y2 [. W" M; X3 [" P( o, k! 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 ~9 K9 A( {2 f8 z8 T2 m set acceleration 0.099( u+ x# [% a* w! F
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
5 {& l; [. a2 m/ k x8 R;; and initialize the traffic lights to one setting
1 O, l, v" d" V0 N/ qto setup-patches
: h$ W8 @7 K# N1 F# q! P5 m; X ;; initialize the patch-owned variables and color the patches to a base-color
. B& z% {# a+ C& l+ t- i ask patches* U. y/ b7 }7 p; f; g/ d) _7 i
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3 O8 p, p. A" X, c) } set intersection? false
7 A& @* R5 z t. w set auto? false. y8 _- j) l1 Y* i7 `2 n* o
set green-light-up? true. B1 S: L2 f9 y: `- f. \- P
set my-row -1" o. H* L( x$ Q. ?- R
set my-column -11 F ^# _+ z% |4 ?
set my-phase -15 j! F" g4 l7 h6 S q
set pcolor brown + 3# O1 E, E3 v }
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;; initialize the global variables that hold patch agentsets- |1 G5 c; S$ j6 w' U2 Y' @- O/ S
set roads patches with
' p9 H( l+ v: \8 q+ I8 T [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
+ L2 N6 Y/ q P5 {& j% W (floor((pycor + max-pycor) mod grid-y-inc) = 0)], {$ A$ P" y/ c# e3 m
set intersections roads with" H" ]" Q6 j2 h+ }1 W7 t
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
8 E, [; _1 y4 W% ^ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]4 R' S3 D9 }, L3 [% {0 h+ p: _* {
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ask roads [ set pcolor white ]" S+ T6 W, s; E
setup-intersections- ^1 {4 b" [! c* j! H& z' j, D
end; S7 C9 ]' s: }) V& g7 \
其中定义道路的句子,如下所示,是什么意思啊?- b2 E% a, G p0 R2 ?2 j+ t9 ]" U
set roads patches with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]: I% f: u* ?% U' Y/ Q7 D/ ~6 M6 U
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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