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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 R: ^ _% ?! j' B7 f; E+ P0 B
netlogo自带的social science--traffic grid这一例子当中,
! ]: S w# i8 M; W- z6 jglobals
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8 q! V: X; o) [5 B9 ? grid-x-inc ;; the amount of patches in between two roads in the x direction2 S2 L, ^0 m; m/ e; ~
grid-y-inc ;; the amount of patches in between two roads in the y direction
]0 C' X( ^- `5 Q acceleration ;; the constant that controls how much a car speeds up or slows down by if, A5 G8 u% o, c. z) p' y' ~
;; it is to accelerate or decelerate% O# B! z8 [) P/ [
phase ;; keeps track of the phase! d' o8 |$ n4 m2 v- ]2 u+ A
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
9 b( c P- B0 m! ^$ N$ {* f current-light ;; the currently selected light+ j+ }+ |5 F. j1 x0 b6 D
+ U) ^4 z' E% y; q! G4 G ;; patch agentsets
# ?) k' v, B& y5 D intersections ;; agentset containing the patches that are intersections- X! M! g K2 {' Y& m% T$ M# p8 l7 L
roads ;; agentset containing the patches that are roads* h! ~6 D& h) T/ {. X* g
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5 v+ z$ n: ]/ @% O7 }3 g$ ?turtles-own# f5 ~% F/ r6 z) f1 r% z+ w4 n
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' y) A" [, i4 l' f/ m ?' S$ R% W speed ;; the speed of the turtle
( d6 N0 Q1 K0 W9 t% ^ up-car? ;; true if the turtle moves downwards and false if it moves to the right
/ R0 H. S; _6 ]% { R o1 H1 U! Q wait-time ;; the amount of time since the last time a turtle has moved
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patches-own/ i/ H2 y. {' u/ W
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intersection? ;; true if the patch is at the intersection of two roads
: _5 q! j+ w2 Y6 d0 K$ k' d S& s green-light-up? ;; true if the green light is above the intersection. otherwise, false.
- y. R1 [/ |7 X4 \) y. M ;; false for a non-intersection patches.
/ V3 K$ t* } X5 l5 d my-row ;; the row of the intersection counting from the upper left corner of the
3 V; B$ R1 F. z; _% ? ;; world. -1 for non-intersection patches.
; T* j3 S0 d9 g& Z8 k my-column ;; the column of the intersection counting from the upper left corner of the
' q" ^& H& s; ^: q/ q ;; world. -1 for non-intersection patches.
$ Y" }5 `4 m/ ]" h my-phase ;; the phase for the intersection. -1 for non-intersection patches.
K5 K. B; ]8 M; H& S) k auto? ;; whether or not this intersection will switch automatically.7 G% Z6 ?, m+ [$ k3 ~2 e" Z
;; false for non-intersection patches.
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0 `) l. G: }3 E5 E$ P;;;;;;;;;;;;;;;;;;;;;;
: ~, L& C5 U, r5 p+ Q' J;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
4 @3 M/ @" f& ?! N1 g e( P7 ~! l;; Create num-cars of turtles if there are enough road patches for one turtle to2 G1 s& R* r" {5 M
;; be created per road patch. Set up the plots.0 m0 t1 a9 E$ Q# {6 O ?+ Z
to setup3 p" U! ~6 @+ {9 s6 H" _
ca
- R' C4 G& R- r' y setup-globals9 n7 X1 V: s6 `# H p2 ~* Z
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;; First we ask the patches to draw themselves and set up a few variables
' r" o8 ]* `1 c9 ]8 h3 |+ y setup-patches2 O6 C9 X& y3 ^$ [
make-current one-of intersections- P* a+ Z4 { H1 i4 i
label-current
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set-default-shape turtles "car"5 ~. c+ I! t# a, m6 |
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if (num-cars > count roads)
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! Y2 G8 `" n4 g; u user-message (word "There are too many cars for the amount of "' ~8 M5 Q( U% E/ h% U
"road. Either increase the amount of roads "; D9 W3 a/ @6 ~$ h
"by increasing the GRID-SIZE-X or "" I5 S/ \% u6 O# h' c3 ~
"GRID-SIZE-Y sliders, or decrease the "7 Q5 p, J Y( t1 S/ e9 P* R) m
"number of cars by lowering the NUMBER slider.\n"
6 J/ `* E9 h8 o) n- ?' w3 { "The setup has stopped.")! Y6 c1 _( h- r, S6 e _
stop3 ?7 f9 p2 t4 Q6 ~' ~! Z! N
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
9 ^! Q/ Y% v& f0 w. b crt num-cars
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7 ~6 W2 [+ g0 F. [1 ]9 H setup-cars9 C' C" |' N) q
set-car-color
% R K: T! J! E x' b record-data1 M( o7 D, b3 W* O
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;; give the turtles an initial speed6 E t, U3 h! h7 a: Z
ask turtles [ set-car-speed ]# H; }1 v$ L' e N& T, u: ~' h
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reset-ticks9 V* p6 @ E |6 B' r
end
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;; Initialize the global variables to appropriate values
& I6 O$ M; d% [% G* }' E! `to setup-globals C( d4 b1 \/ ~/ t
set current-light nobody ;; just for now, since there are no lights yet9 t$ V+ z7 }: V. n( p4 N O
set phase 0
$ r- f7 X6 h' R% q/ `5 V set num-cars-stopped 0
1 Q Q P! T2 y. G set grid-x-inc world-width / grid-size-x
0 H* J! J1 i2 Y set grid-y-inc world-height / grid-size-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
+ f* P. s8 Z! p$ [ set acceleration 0.099- P# H5 t: O+ V& c" h
end- P7 |& s8 g- a1 D% T2 Q
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,/ n* O0 D' S8 q ]
;; and initialize the traffic lights to one setting
+ N0 j4 b. @) J h( O7 l' f' `8 \to setup-patches" K( K! ~& F- `% m y
;; initialize the patch-owned variables and color the patches to a base-color* R" m- T( `2 A3 _: F
ask patches' L! S/ w1 h: q; S1 f O8 ^
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* f' J* N7 m! a, b+ `* O2 V set intersection? false
% y5 ~5 L) |$ s4 J' A7 D2 l set auto? false
1 p. t5 {; k; P; z set green-light-up? true8 G" u5 l# _. K6 E+ v
set my-row -1
9 E/ @: E7 N5 K5 L* j8 z% y set my-column -1' o, `5 ]2 o- q1 u3 g5 y+ ?2 d" u
set my-phase -1
4 e/ I1 R, Q. A" W3 L set pcolor brown + 3
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" ~# |- C7 m/ D: F# t ;; initialize the global variables that hold patch agentsets
( X1 @+ W- z. I# d& d2 c set roads patches with5 R1 [3 ~. Z* v9 S
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or- R' [* }3 Y5 P, ^3 t# ~- q
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]- m8 k4 {6 ]: @% f/ |
set intersections roads with7 o5 q# b5 N: t$ w, M* K2 r1 }% [
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and# x, H& X) @. E; e3 y( J2 Y) }
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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# s$ J) d* E4 M" K7 P( T1 F ask roads [ set pcolor white ]' \% |, O: s' G8 K8 z
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?
4 O! n G @, }) C. \- u0 D- d$ f$ v set roads patches with
& A! z N! U K1 g. ?% L, H- Y5 M$ W [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) w7 r" u% u5 g, P/ J/ b! l
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 S- C9 H5 b6 P+ P4 o R' g6 e- I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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