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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。$ Y2 k- C+ k4 w. i
netlogo自带的social science--traffic grid这一例子当中,
5 X3 ^; J6 R. N& U$ Z: l- |6 ?globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction; [& L5 c, [ L: ]+ F
grid-y-inc ;; the amount of patches in between two roads in the y direction. q$ g, J% \) e8 M4 j
acceleration ;; the constant that controls how much a car speeds up or slows down by if+ S5 a: x) e" f" X. }( j) u
;; it is to accelerate or decelerate# ?3 }) m. C# W8 ]# _' d) O) Z
phase ;; keeps track of the phase+ K5 S. a) I) `
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure* D; `4 R$ w0 Z/ u4 k
current-light ;; the currently selected light, J% ]) o: G" j* D4 E
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;; patch agentsets8 e7 Y+ V5 `9 h; M
intersections ;; agentset containing the patches that are intersections
5 O" |: E* P# ?% j+ c$ f8 w3 p1 A roads ;; agentset containing the patches that are roads' ~& \3 q/ N" ?
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1 v7 M H; _2 H1 q! Q$ S' c' c% H$ {9 hturtles-own
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speed ;; the speed of the turtle
+ Y* ]% e' o1 g! t/ M" B+ r up-car? ;; true if the turtle moves downwards and false if it moves to the right
- }3 Z# ]3 W# G1 R wait-time ;; the amount of time since the last time a turtle has moved4 U7 V- W. o9 u& c6 Y3 C* @
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patches-own9 ^- ` H) P2 v% B
[
; ^7 l9 R) {. x: Q# V/ X+ y intersection? ;; true if the patch is at the intersection of two roads7 a9 ?& U) r' v, }: p2 |
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
2 U; d& _ {6 @( P ;; false for a non-intersection patches.
6 E- e- B1 ?6 o" L my-row ;; the row of the intersection counting from the upper left corner of the
% q8 b0 J/ i+ n1 Y6 I( u9 Y' W ;; world. -1 for non-intersection patches.
) W& d- y7 ]! k% @ my-column ;; the column of the intersection counting from the upper left corner of the
6 \* \5 y1 `- N* w ;; world. -1 for non-intersection patches.
- L, F' R4 n. k2 O6 o1 x my-phase ;; the phase for the intersection. -1 for non-intersection patches.8 ?. w+ Z& U0 R0 Z8 r) Z" e" M2 j
auto? ;; whether or not this intersection will switch automatically.7 }: d4 p& X( t& W
;; false for non-intersection patches.; ?# ~* a* F7 X! f7 D
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- r5 [2 X- \9 u1 X: z;;;;;;;;;;;;;;;;;;;;;;
; X6 O& ^* |' D8 |. w l1 ^;; Setup Procedures ;;
3 z6 A# ]# F) y;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values., A. a) Z0 I4 I+ y! Y& X
;; Create num-cars of turtles if there are enough road patches for one turtle to
# P3 z( N$ V. i;; be created per road patch. Set up the plots.% I/ j( J. R2 N |% Z @
to setup
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" m: E& }0 X. ~6 H" K. ?; ]' F d setup-globals7 ?6 m' x7 S+ T
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;; First we ask the patches to draw themselves and set up a few variables5 P# \- ^, O4 i3 _' {. T3 \5 f8 K7 U
setup-patches3 n: `+ E8 d- Y' j5 |
make-current one-of intersections: i4 D. g* p0 L* L8 b
label-current' w: S. ?/ E0 w. i! N6 S0 q
3 c- c$ c9 c H& i1 W: | c7 z# F set-default-shape turtles "car"1 e8 {6 W2 q* e3 [
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if (num-cars > count roads)
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0 N, j$ N6 S/ O1 S8 t) a5 T user-message (word "There are too many cars for the amount of "7 t- R3 M/ @( T4 p( A5 Z$ m6 a
"road. Either increase the amount of roads "6 Q: X0 a$ a2 ]1 N# H l4 G6 c
"by increasing the GRID-SIZE-X or "
: U9 z Y! y1 ]+ L "GRID-SIZE-Y sliders, or decrease the "
# a ^" i! f: h9 U/ t0 f( W "number of cars by lowering the NUMBER slider.\n"
3 A ~$ a" D4 \* C "The setup has stopped.")
+ W* E" P8 u2 u1 ?7 K5 ?, X stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
* Q9 N3 \, M b s$ D" o crt num-cars% n' i: I0 o y. E) r, ~
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% `& l! v; H+ V- L7 {9 A$ r( m5 u setup-cars
; r1 w3 W' n" |$ j* I set-car-color
' s, t" ?4 G2 q+ C record-data) s2 Q, M3 H4 b: R0 o0 ?, u# C
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;; give the turtles an initial speed9 H4 U; D' [; r8 }( e4 x+ N4 d
ask turtles [ set-car-speed ]
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" L7 S8 X5 u4 Y3 M; [1 m' n reset-ticks
9 ^/ O& D$ W. d$ Q W/ wend
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;; Initialize the global variables to appropriate values# }$ Y1 R0 a$ J" O
to setup-globals
0 v$ I m5 M" j! b8 f set current-light nobody ;; just for now, since there are no lights yet9 q% G8 O" x( X2 Z1 B8 A
set phase 0
" n* c9 [% A* P set num-cars-stopped 01 |2 j0 T6 B" g _5 ?: c7 U
set grid-x-inc world-width / grid-size-x4 C& v& Z* K m3 j5 ^6 }
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
9 ]; }) w7 |* x4 i d, w O$ m3 C set acceleration 0.099$ O# e- c U5 m0 y: E8 B( W! [
end& ~5 V- h, ]( G" p# m0 X" o6 c
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
3 J2 u3 C( @+ H4 P;; and initialize the traffic lights to one setting
# ~) ^7 Z+ Z! y- h# S @to setup-patches3 [3 i' H9 }4 @4 R4 [& R, C% P
;; initialize the patch-owned variables and color the patches to a base-color
0 z2 v/ E% M7 G% L I' Z9 h; I& l0 B ask patches
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: Y# q) k1 z8 ]( r+ X( N. V set intersection? false8 C d7 b% n+ D7 i
set auto? false' ~. |: I H/ r# E3 D& q
set green-light-up? true
8 M3 G. k7 P/ a8 b: N$ d set my-row -10 W1 f# f. s2 V6 R. ^9 X
set my-column -1
" \/ G* }* ?, v set my-phase -1
1 D }+ t! N$ J1 z set pcolor brown + 3
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: ^, i: g9 v9 d% \" p ;; initialize the global variables that hold patch agentsets1 ]6 _6 s8 C5 a5 _
set roads patches with3 J0 i) H" B4 D @$ Z
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or5 e0 g3 M; x, B0 Y& m
(floor((pycor + max-pycor) mod grid-y-inc) = 0)], {$ `5 t, @% ]* x G
set intersections roads with
; L8 e" S8 T9 P6 h& r; d+ O [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
4 d* t$ n1 Y7 I; v. @$ }7 I (floor((pycor + max-pycor) mod grid-y-inc) = 0)]) r7 K# k' P5 e2 S4 M3 r, I+ r
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ask roads [ set pcolor white ]
1 a* }, f) u2 S9 t+ F setup-intersections3 ^9 F$ }% C' d c( N$ V
end2 J7 K1 x- M! W+ q7 `' }
其中定义道路的句子,如下所示,是什么意思啊?
* U* @6 S( ~3 Q% } set roads patches with
1 k1 H3 T1 s9 t& |8 T [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or3 p* H% P* Q9 f
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 q) Q1 b! Z- m3 y) Z& I( e8 _; g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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