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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。2 j+ l$ L; ~5 ^( S* b2 G, U6 i
netlogo自带的social science--traffic grid这一例子当中,
2 G7 O1 S" S, d. F1 M- g: [5 A+ nglobals
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6 o! v" I9 L4 \* Z1 w4 K" g grid-x-inc ;; the amount of patches in between two roads in the x direction
. b( Q. l* `# T! f: f2 T) a" L grid-y-inc ;; the amount of patches in between two roads in the y direction# ]" W. l" N4 f% i: d; M- ^
acceleration ;; the constant that controls how much a car speeds up or slows down by if
" W4 ?; b) u3 T3 N0 x8 ^7 n* [, L5 ^ ;; it is to accelerate or decelerate/ r i, S2 j! ]2 Z
phase ;; keeps track of the phase
# r, B; w. d1 J. K$ z4 i$ j num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure: R! g' Q, a" y* @8 p
current-light ;; the currently selected light
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;; patch agentsets2 q# F& @6 f0 X: z' C4 w. S
intersections ;; agentset containing the patches that are intersections
& q2 @7 H" ^/ Q% O, E$ l roads ;; agentset containing the patches that are roads
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! i, x- Y6 [0 n: L4 t; `$ Bturtles-own
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+ O, J" G5 T' {3 V6 ^ speed ;; the speed of the turtle2 B, a. N9 e$ X5 O- B- j9 Q& o
up-car? ;; true if the turtle moves downwards and false if it moves to the right U7 ~6 O: O3 U6 B
wait-time ;; the amount of time since the last time a turtle has moved6 N9 l0 e' m" Y, i4 Y, _; K: i% s& O
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patches-own- B0 r+ S* m. S2 r9 Y1 T3 Z
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intersection? ;; true if the patch is at the intersection of two roads
2 M3 I1 O: C1 h6 F green-light-up? ;; true if the green light is above the intersection. otherwise, false.+ @4 L y2 v- c" a. K. E1 l
;; false for a non-intersection patches.- e( b# a Z' J
my-row ;; the row of the intersection counting from the upper left corner of the
6 b* W4 |) B% Y3 o4 c {) c! S ;; world. -1 for non-intersection patches.: ]' i: e, @/ s/ _* ~
my-column ;; the column of the intersection counting from the upper left corner of the
3 Y/ ^. @5 ]' Q) j: d5 ? ;; world. -1 for non-intersection patches.0 t6 p$ Q; k, I$ `& B
my-phase ;; the phase for the intersection. -1 for non-intersection patches.% f& o% W8 S# l3 O4 N2 S# O8 E
auto? ;; whether or not this intersection will switch automatically.$ n( k: x4 c" w a( w2 H- u# a. y
;; false for non-intersection patches.; ~# l' ^' [6 i
]
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, l/ X, ~& c6 c# x* `;;;;;;;;;;;;;;;;;;;;;;3 L- C7 a: f5 [! T: z
;; Setup Procedures ;;
' G3 x- Q/ v" j8 l;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.& G1 T, X$ x( Q
;; Create num-cars of turtles if there are enough road patches for one turtle to2 {& ~+ B) D/ _- K. E3 }2 d
;; be created per road patch. Set up the plots.
" Y& J+ U3 h- |6 x, ]3 P, s. Cto setup
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5 l( [2 E9 i7 ?; K6 G setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
' q3 y& A# n: Y( w setup-patches9 Q8 Z: i0 r! @! c8 n
make-current one-of intersections- D# j* w3 K* N0 s; `
label-current" E2 e, Y# r3 k: _7 m2 [0 G
& j. {1 d$ V9 f9 }7 p set-default-shape turtles "car"# N# _: H6 p5 N0 f
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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 "1 W. G* P- k: w6 i7 w. l" M* \
"road. Either increase the amount of roads "& e* T i- ]& x7 U! e* ?. Q7 y
"by increasing the GRID-SIZE-X or "
! Q$ U8 c0 L. F6 ~* h3 Z: H6 q& m: U+ P "GRID-SIZE-Y sliders, or decrease the "' Z7 y8 r8 ^; f! Z8 u2 ^
"number of cars by lowering the NUMBER slider.\n"8 n0 B* r3 H! i" k
"The setup has stopped.")
2 l( c3 T* M4 |- I+ Z0 ^ stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color" W8 [9 \1 k" R+ r
crt num-cars( m6 g4 R! @8 w0 _4 P
[
) W7 X# w1 p8 i! [ }! b) X) g setup-cars
$ P0 L- l: }/ {! ~ set-car-color
. J* n4 d3 k1 X' X J record-data; b0 ^& a8 p0 d3 ~# q
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;; give the turtles an initial speed+ b! V1 f: h+ H/ r8 n5 I
ask turtles [ set-car-speed ]
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reset-ticks( N9 P& a6 ^! q. x x
end
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;; Initialize the global variables to appropriate values1 _* b! O9 \6 t6 S" Y, x( Y
to setup-globals) J8 h7 r e% H, z5 M
set current-light nobody ;; just for now, since there are no lights yet
' A: c9 X) ~& b S$ [, R set phase 0
7 R% a% Y+ \% |6 } set num-cars-stopped 0+ v5 f) ~) p& C
set grid-x-inc world-width / grid-size-x2 u" R8 H$ Y* k+ }& ]! K2 H* y
set grid-y-inc world-height / grid-size-y: ]0 r) \' {8 I: Y: v. m" x
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
+ E' Q, U) ?6 H8 ~) i set acceleration 0.099 ~2 N( q3 n$ c: r! ?) }* g
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,1 Z' d8 P; I7 j3 _$ I% h
;; and initialize the traffic lights to one setting
2 r5 u& v4 V7 V" m! nto setup-patches/ v; o. U9 c+ B
;; initialize the patch-owned variables and color the patches to a base-color
4 G6 i1 O2 B U% \* t ask patches6 l& f7 z8 _! L" [
[
- v% a- d9 g* W1 f set intersection? false
* `. j1 Z8 Q! K- c4 b" K4 Q1 `. C set auto? false
4 d+ D+ g) N& e& V# | v set green-light-up? true
5 ~; E, w1 e- x4 _9 _+ Y0 E set my-row -1+ f9 F) D: c% W7 t7 a
set my-column -1
& z- h* H! z# P7 T8 l set my-phase -1
3 O0 X; Y+ |* r2 e. W4 X1 E set pcolor brown + 3
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) E7 G% O3 O" T) r e8 k! F7 I ;; initialize the global variables that hold patch agentsets
( ?* K3 i5 s q/ Q& t- V; R set roads patches with
1 d/ j+ P- N1 k4 s" M, e8 ` [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
0 r( D: [1 o% ?" Z* J0 L (floor((pycor + max-pycor) mod grid-y-inc) = 0)]4 \! p7 {. F5 n/ c! v9 B. {8 a
set intersections roads with
2 H, G0 W; D: {4 Q* [5 L+ P [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
( U: c2 d4 u" ?+ H' ^" q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
3 Q0 J E0 f Q$ S( [! D setup-intersections
$ B, Z' f' h9 o: [' J$ Nend
: M* A' I+ b; O8 R' K其中定义道路的句子,如下所示,是什么意思啊?" u* C Z2 `6 Z& O/ S
set roads patches with
+ X5 |* ~' [, h# _* h1 O/ L [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 q# h/ v& {* L
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]; t: _4 h- [1 W; Q
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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