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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。' N% S- \2 D8 c% h+ A
netlogo自带的social science--traffic grid这一例子当中,$ u: Y1 ?7 H+ \! Y) Y' i
globals/ D: L, a* E$ Q2 i/ r
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grid-x-inc ;; the amount of patches in between two roads in the x direction) g1 h7 }) U* T: u
grid-y-inc ;; the amount of patches in between two roads in the y direction
) o6 [; y2 O( r7 ~, B acceleration ;; the constant that controls how much a car speeds up or slows down by if
% z& Z, r4 R2 B1 ~ ;; it is to accelerate or decelerate
7 t2 Q8 ], |$ i% }* C5 Z* s3 A2 a3 } phase ;; keeps track of the phase* F! }" E6 t2 J3 v+ k6 r$ @
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure3 J0 N6 l3 I, {& W' N
current-light ;; the currently selected light
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;; patch agentsets4 j. O* T$ C; l5 t
intersections ;; agentset containing the patches that are intersections
3 F, Z& G. k! E L, k roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle
4 |- x, b2 A" L- x up-car? ;; true if the turtle moves downwards and false if it moves to the right8 N$ i n9 m$ u) l5 H) l, J
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own3 l P; g! `9 w0 Y% a
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intersection? ;; true if the patch is at the intersection of two roads
3 Q8 L5 u- I+ E& B green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! k) }1 u4 m' _% R) Y ;; false for a non-intersection patches.
, {- n' L8 V r& x" w my-row ;; the row of the intersection counting from the upper left corner of the
$ b( ?2 L& w& a& F ;; world. -1 for non-intersection patches.! A; `$ a2 ^1 I1 s' _! K- E
my-column ;; the column of the intersection counting from the upper left corner of the
- s; ]6 U f+ x3 \/ |& d ;; world. -1 for non-intersection patches.% Z) x, i4 Y8 I, E
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
: |8 z: m `" Q' Z$ D' |8 c0 { auto? ;; whether or not this intersection will switch automatically.: _# k7 N, C- v8 ~
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
0 M S* `1 ?0 ]3 a+ m2 t& F5 |;; Setup Procedures ;;
) G, d. W, p2 `' H: r% X;;;;;;;;;;;;;;;;;;;;;;
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. D k2 l/ N+ W! H0 ]- S- A6 B;; Initialize the display by giving the global and patch variables initial values. [0 N6 H }( h1 F, z; Q3 O
;; Create num-cars of turtles if there are enough road patches for one turtle to
+ ^ Q( g$ F7 t" O* L4 C;; be created per road patch. Set up the plots.. _) f' l! N' D3 t5 }3 D
to setup
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setup-globals
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+ D' `; \$ C- d4 E9 t" d' n! Z7 E ;; First we ask the patches to draw themselves and set up a few variables3 M! ~) Z: j: t: K# T- x2 d4 [
setup-patches/ a' }. A/ @- Y
make-current one-of intersections: {1 g" n6 e+ k) l* N( D+ g* X
label-current2 E1 |: Q/ q2 y
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set-default-shape turtles "car"
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- b' ?- {' W' k, q# U8 f if (num-cars > count roads)* F* F2 s! y q7 V' W. L& h
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6 {3 ~/ n# t2 ], D* b( X* z user-message (word "There are too many cars for the amount of "
3 Z1 q# X1 c4 `* @4 X "road. Either increase the amount of roads "
- U( f; i4 P0 O. @6 u r3 u "by increasing the GRID-SIZE-X or "* \% `* R9 Y0 [; i. g5 F
"GRID-SIZE-Y sliders, or decrease the "/ E" k; f- B' I0 k& {
"number of cars by lowering the NUMBER slider.\n": J4 ~- I( m( f( z( O# J k2 f9 j
"The setup has stopped.") c" g# G8 M8 F" z
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color# M: J8 g( S2 r; C- ?6 `) m+ p; T
crt num-cars
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setup-cars
3 E' [% P: K4 M, ?2 j set-car-color
5 {0 @2 n5 H. u record-data
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. P6 B$ F G4 ?" {; G ;; give the turtles an initial speed
4 D7 n% ^! a# k ask turtles [ set-car-speed ]3 ^+ w- }9 f8 Q5 }# _/ P
/ {$ h) C, ?) V$ J( m A reset-ticks" E% C G9 \- W- Y
end
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7 d+ P7 h3 B- |7 ?* Q' {1 E;; Initialize the global variables to appropriate values6 t5 t" R( {$ R1 Z
to setup-globals+ ]7 h" X1 F+ h4 v' W7 {
set current-light nobody ;; just for now, since there are no lights yet
4 F8 V B2 D/ W- ? set phase 0
8 t# y& v: F/ R. M set num-cars-stopped 0& ]# ]) d D* V0 r: G/ i
set grid-x-inc world-width / grid-size-x7 ]$ o7 t+ Q: Z( F
set grid-y-inc world-height / grid-size-y: K" ?. S7 ~$ y6 D7 o
) b1 l4 H( L# p# s% @8 d ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary; z5 A" o/ {# F B$ O- v
set acceleration 0.099
/ C' ] E7 H. }end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
3 L4 |: J/ M. J: z. d7 z;; and initialize the traffic lights to one setting
7 |7 m% C# M, T- J. M, ? O& g M: d; Ato setup-patches
) _$ y& ]# o+ L1 Y3 a- b% R ;; initialize the patch-owned variables and color the patches to a base-color# q. y3 |: l" P; S# m
ask patches/ X: ~ f+ q) g3 ^) K' L
[
% E" H" e7 `" M& A, b set intersection? false
+ u. @# S3 E6 q1 x* r0 } set auto? false2 Y# h: @8 c1 h" ?
set green-light-up? true
, o" ^. V8 i9 k set my-row -1
7 Q- T5 c- ]' _: Q. S, v+ q set my-column -1
5 G+ p. v: o& d3 F o& ? set my-phase -1
B' V; u6 ?& S" t8 ] set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets4 z- y7 F0 r P5 f$ t
set roads patches with# M" p; f, J r9 H: E7 t! H
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or6 Z3 i- a& p- J3 y7 A& V2 w4 ]
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
& Y6 |4 V, m+ P- I5 d5 A( y$ u set intersections roads with" F4 ]$ B1 ]9 s) O4 e; W
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
: z' i+ S( c6 ]& _ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 A# d2 o r8 D) D
% d5 E: ]' q: Y5 k: ] ask roads [ set pcolor white ]7 N7 d7 J4 R2 {9 g
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?
1 W6 N. @8 V3 I- R7 u. k set roads patches with$ N" T! _( r. v* U: \, z
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 @1 s: m+ ?9 r/ g( t+ Z; Z4 Z# Q K (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ J/ D2 O o' Q; B9 X5 l, 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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