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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: G# _% t; y, I6 |netlogo自带的social science--traffic grid这一例子当中,
" Z# E& ?. w; o z9 a0 g* sglobals/ B+ q- B2 h+ k$ j4 Y
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grid-x-inc ;; the amount of patches in between two roads in the x direction/ H! W2 z7 \/ f7 r3 ~7 f7 H
grid-y-inc ;; the amount of patches in between two roads in the y direction; e4 ]# S1 P7 d: k: r" W
acceleration ;; the constant that controls how much a car speeds up or slows down by if
$ i: V) N! L$ j" U) t$ j. x5 p& r$ F; H ;; it is to accelerate or decelerate1 @' R4 W, t1 a, i [) ?
phase ;; keeps track of the phase
" f" t) `+ C8 e C num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure+ g, |. |" @) c% ^7 h0 M& C
current-light ;; the currently selected light
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$ h. ?; o' [6 N! |# H' L( w' g ;; patch agentsets
" k2 X6 c" \; Z% j$ i3 V- _% a intersections ;; agentset containing the patches that are intersections
% L1 `- f4 @8 I4 M6 W7 F9 Z) s roads ;; agentset containing the patches that are roads
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turtles-own
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. Q$ i$ E! Q* Z speed ;; the speed of the turtle5 |7 J( J! r7 ~7 w/ t; y
up-car? ;; true if the turtle moves downwards and false if it moves to the right8 |$ o( b% \& d6 e) \& h# g- r
wait-time ;; the amount of time since the last time a turtle has moved, i. K% q- g2 Q% \4 w. _" |
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patches-own' R ~: o4 b; i4 E7 l% z1 D1 _
[
* K f* ]! R# ]) n6 U/ b" k/ P intersection? ;; true if the patch is at the intersection of two roads+ g) K6 S) U+ A) G
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
2 o$ K4 u6 z$ B) R7 W" M' X( y9 X; S ;; false for a non-intersection patches.0 M* t! ~( j, U L6 \6 @
my-row ;; the row of the intersection counting from the upper left corner of the
. K: B% ~! i* w+ M ;; world. -1 for non-intersection patches.' Z2 B9 |" S* L/ M, l3 w
my-column ;; the column of the intersection counting from the upper left corner of the
$ e. x% n% W; h ;; world. -1 for non-intersection patches." U/ c3 ?* `! ~% ?$ j- ]4 B# F7 q
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
* t% J2 T+ ?% ]- W9 o auto? ;; whether or not this intersection will switch automatically. r1 x" J( x! t) l+ T c, X" H
;; false for non-intersection patches.( [, ?% Y: x+ ]! `( C r) _* H. s
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. ]: `. ]8 h1 Y;;;;;;;;;;;;;;;;;;;;;;! o# w7 C0 V) A) ?, m) G) I- J9 H
;; Setup Procedures ;;
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6 N# y" H# t5 ^% S# l;; Initialize the display by giving the global and patch variables initial values.& V# J/ V4 H0 V
;; Create num-cars of turtles if there are enough road patches for one turtle to* T* Q1 X* [1 a# n& S
;; be created per road patch. Set up the plots.) ^, x# Y5 D9 v F8 r
to setup
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setup-globals1 Q W0 s) _" M$ M, x Z& t* r: X
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;; First we ask the patches to draw themselves and set up a few variables
) |, b: T/ m, H+ F/ n- J" m setup-patches
) Y* W/ n6 |1 i/ z$ r4 ~9 @ make-current one-of intersections
* \8 j- E7 a6 Q$ Z" u: g" q' R label-current
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set-default-shape turtles "car"
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@" e2 V) e+ a" O/ E, i) L if (num-cars > count roads)5 G; A) }8 M( D% r1 Y
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user-message (word "There are too many cars for the amount of "
' J5 [0 W f2 S5 ^$ f9 Z9 A "road. Either increase the amount of roads "3 o, U; v1 s4 p5 T$ h
"by increasing the GRID-SIZE-X or "
( h; }: @+ ?1 [7 y( T# z "GRID-SIZE-Y sliders, or decrease the "
1 I0 n( _4 W7 ]; _, N3 z* ~ "number of cars by lowering the NUMBER slider.\n"
: @ ~! F# o4 v8 ? "The setup has stopped.")
/ k7 F$ S! Q$ f$ P7 t1 b stop
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: c+ O) C* {8 |/ y7 t' { ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
& |, J* C$ @0 [4 w0 ` crt num-cars# g7 B) t# r9 E2 q& A1 w
[
$ U2 X! g; `2 S. p$ K9 { setup-cars
1 ~9 x* R2 h8 M set-car-color7 \5 Y/ u* B3 G+ R4 ?$ p; V
record-data. F* h' U% O% h( K5 k, b8 u; e
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;; give the turtles an initial speed; u5 k8 f: X% p( Z5 \3 B! g
ask turtles [ set-car-speed ]
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reset-ticks. x0 X9 K- v5 B5 ^8 B, U
end
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- [" h' i! {) u) P- h' I;; Initialize the global variables to appropriate values
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7 Z3 q0 X8 ]2 p7 ` set current-light nobody ;; just for now, since there are no lights yet. D% V' u; i# q! S, L
set phase 0
- J6 x0 a4 ], M' t# s5 o0 j8 ] set num-cars-stopped 08 G! G+ R7 a% x* b" _/ ]/ \( x- R
set grid-x-inc world-width / grid-size-x/ B& i" k2 G% d2 I
set grid-y-inc world-height / grid-size-y
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6 Z! c2 Q8 t- K e9 N ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
6 V: F B+ V( g9 { set acceleration 0.099
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# ^- b) ?7 e) o1 D% g% |;; Make the patches have appropriate colors, set up the roads and intersections agentsets,( u" M& d/ ^" _( H1 c
;; and initialize the traffic lights to one setting
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;; initialize the patch-owned variables and color the patches to a base-color
+ |+ K3 y5 z: [! v/ ?8 M/ x ask patches
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set intersection? false
5 V6 e& f' A2 H6 P, Y6 v( X set auto? false; w$ K3 H- ~! b/ a9 Y
set green-light-up? true
" X" e5 ~" A3 k. j2 P" O set my-row -1! D- q/ I- k, I8 k- ^ Z8 }
set my-column -1# c! \2 O& b! P
set my-phase -1" [! S. N3 v8 Q& A1 O
set pcolor brown + 39 ]3 e% ?& H1 y/ h
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;; initialize the global variables that hold patch agentsets! J- O% h- y9 j; h
set roads patches with
" m0 Q% b7 ]2 r( S [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
3 K9 V J% P; c l& ~) N( Q7 e (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* M( ` q( F$ z- O; ?, x% m+ Y set intersections roads with8 s2 u" ], R6 j9 X. ` e$ o$ s
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
3 f! x. d6 [% ?: `3 V$ l/ r (floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ `* S9 Q; n" e+ F( ^
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ask roads [ set pcolor white ]9 D0 C- K4 U% C) k" b( q. Z
setup-intersections+ ~/ v- @$ z$ d0 a! |/ M/ a7 w$ M
end- R! C$ }" ^, L' B+ `
其中定义道路的句子,如下所示,是什么意思啊?$ L( v" r( m Z; F! W. y# l
set roads patches with+ Z8 R: p2 K/ t' ?4 k' I4 R# _
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# Q' D, Q% q/ \5 _9 r! [& Z2 } (floor((pycor + max-pycor) mod grid-y-inc) = 0)]8 p" }, Z9 L g* H3 p; f
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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