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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。 `5 {3 d ?, _( Y# U
netlogo自带的social science--traffic grid这一例子当中, H' x J! w" s! L0 z$ x$ v& D) `
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
o: u! h/ e! b% @; a8 T grid-y-inc ;; the amount of patches in between two roads in the y direction
$ f3 e( |5 {9 `) M( `- A acceleration ;; the constant that controls how much a car speeds up or slows down by if: G8 q% }3 c$ t9 L/ s4 `7 f
;; it is to accelerate or decelerate- E7 @0 L- I& d" `* s9 ^9 j
phase ;; keeps track of the phase
& q' [. Y9 i9 C- N" W' \ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure& [. Y, G, @, g8 f9 r# p$ ~8 B
current-light ;; the currently selected light% J6 ? L2 ~5 a, D0 q
8 T. ~- g8 T2 y3 i7 ? ;; patch agentsets- U. N1 K$ A3 `, U1 l z6 Q! W; f
intersections ;; agentset containing the patches that are intersections
5 {5 C" l8 B* B4 _ roads ;; agentset containing the patches that are roads4 U ?& G0 M+ v# d8 N I+ S
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9 ^, K# W/ E8 Z Iturtles-own
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" p7 k# z1 k( J9 k1 y3 W. Q- ] speed ;; the speed of the turtle
4 {4 n1 b' p- b- m* O0 x up-car? ;; true if the turtle moves downwards and false if it moves to the right
5 Z a: Q( R' a# W/ _! p/ d wait-time ;; the amount of time since the last time a turtle has moved
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: @0 g4 B; }# D+ J3 H# N2 Mpatches-own$ i( } c) {, _0 V# E* M5 D
[
) w) t0 I9 ~6 h8 l: w. V; D intersection? ;; true if the patch is at the intersection of two roads' q, P- G8 I2 S$ M4 X6 ~
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
# H* e2 d# o. M: \ ;; false for a non-intersection patches.
" C6 t) l$ D Z, I+ i4 C my-row ;; the row of the intersection counting from the upper left corner of the m0 [! [( c3 a5 [ V! X( D
;; world. -1 for non-intersection patches.
$ P; J- {! O9 E/ t my-column ;; the column of the intersection counting from the upper left corner of the
q$ d4 ?: B# ?9 |7 d2 ~1 ` ;; world. -1 for non-intersection patches.7 Q+ a: g- N; n+ l. _1 w8 @
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
$ O5 c Z- J. A( f( [8 `4 Z auto? ;; whether or not this intersection will switch automatically.
8 E' i& [, P. @1 p, S; C9 T ;; false for non-intersection patches.
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. p$ M8 I, E5 Z, P, K, D1 _6 \* u;;;;;;;;;;;;;;;;;;;;;;
4 ]$ D2 i' t$ _7 L;; Setup Procedures ;;1 A1 n- W+ x- b5 X" L3 ^- M
;;;;;;;;;;;;;;;;;;;;;;0 A6 d0 H( V- m6 n( H) B+ n
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;; Initialize the display by giving the global and patch variables initial values.
* K- J' d% U' ?3 ~+ ~% f;; Create num-cars of turtles if there are enough road patches for one turtle to
4 K4 ~% _0 a! q1 \/ | x: h9 N;; be created per road patch. Set up the plots.
" y0 B- Z, g, B! xto setup+ Y" n$ r) U, a: F
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
" t0 l5 f( U2 k4 ~7 w9 x f0 p3 j setup-patches
9 o5 W5 z9 o& Q: b( y2 O$ y6 \8 D: k' N make-current one-of intersections+ e& t+ K! J/ O2 M% X4 P
label-current
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set-default-shape turtles "car"
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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 ": b- U- o& m+ h
"road. Either increase the amount of roads "
& G- a& C2 ]% P2 k6 \; q "by increasing the GRID-SIZE-X or "! L% v4 C0 p$ t" q( U8 p1 v
"GRID-SIZE-Y sliders, or decrease the " J6 B x# s5 e! R
"number of cars by lowering the NUMBER slider.\n"7 V$ c" A' x! O$ r" y% `
"The setup has stopped.")! ~4 U7 @ D& r
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
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& K0 {# `* T8 z8 S9 b, k setup-cars) N/ x1 l: J) \
set-car-color- |5 S3 e5 _# z! M
record-data
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6 |! u6 m) g9 x- R6 S ;; give the turtles an initial speed) A8 C. C; @% x2 @7 _
ask turtles [ set-car-speed ]8 {# ]/ u1 ]" [2 A, @
7 d8 Y+ \5 a2 b* Q reset-ticks, ]4 J+ [. I( e% Q
end4 ], T8 R" l8 `3 T' k# ~
. ~6 Z. u j1 P# d9 h9 Y;; Initialize the global variables to appropriate values! ~0 E5 A/ H! h+ e% Z! B
to setup-globals
+ m( \; X7 q- y set current-light nobody ;; just for now, since there are no lights yet* I% |) w# | V3 T: R _: i; K
set phase 09 A/ _1 d. ~4 l5 ?
set num-cars-stopped 08 a5 B: X* M; W% H3 O
set grid-x-inc world-width / grid-size-x9 {7 c0 M) Q% ^) |
set grid-y-inc world-height / grid-size-y
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+ R( J/ z, Y$ c# \: O2 Q ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary B7 P1 K3 B1 p& }4 W. O8 A
set acceleration 0.099) b* q) ]: ?3 N6 ^
end
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' s, ]" ^' k% N: r$ [- A;; Make the patches have appropriate colors, set up the roads and intersections agentsets,1 b/ P& j% B; ]
;; and initialize the traffic lights to one setting, u9 s, i) B2 Q' [2 G. {4 n2 t1 f
to setup-patches
: a$ M/ u) T* h( j8 P0 S1 N& X0 ~& M ;; initialize the patch-owned variables and color the patches to a base-color
1 Q+ |; M4 v. N3 [. a& O ask patches
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set intersection? false
+ }+ h% p, p: U1 @$ L4 f set auto? false
. i. w6 H) w9 j& x! x" }7 T set green-light-up? true9 h* i3 E$ q+ |! g0 m& ^2 v
set my-row -1
6 ~6 B9 {3 X$ t) g: s8 ^ set my-column -1, T- W2 o. p' j2 m% I4 R3 S9 {) B3 I
set my-phase -1
# j6 ?: ~2 B. S/ Q& v' F set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
+ d V, Y$ E5 M' H7 w. j set roads patches with+ k& @5 a$ L( o2 s; @3 n- T. T5 V) N# n, X
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
( G8 ?2 K4 F0 D$ u0 q% t* [" c (floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 T/ a: f# O6 b7 M
set intersections roads with
$ x. r6 W) C7 S- C) ^9 F. w [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
$ Z$ l0 v# T0 {! f7 Z1 V$ o (floor((pycor + max-pycor) mod grid-y-inc) = 0)]* Y( p8 {0 W$ d5 n* P, \: j+ A
9 I6 L6 B! K' p ask roads [ set pcolor white ]& f( c# r. X3 h E" @
setup-intersections4 ]2 M) T8 ^, `1 U* ~
end
! Y4 \3 z, u/ P4 p2 ^其中定义道路的句子,如下所示,是什么意思啊?* o. N. E0 n9 t
set roads patches with
" D9 W8 h9 L, M# ] [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
) w* d% F0 c- Y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 L' ^. W) S! G' c6 {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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