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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。
! r) k1 R4 k6 `* a# g( K1 Xnetlogo自带的social science--traffic grid这一例子当中,
- [( o0 }8 O& [( Kglobals* Q6 J! l' E: @, D6 a+ S6 i# j
[
/ z% P m2 G& p+ p6 A. h1 H grid-x-inc ;; the amount of patches in between two roads in the x direction8 f) L2 d: {* p8 z5 T
grid-y-inc ;; the amount of patches in between two roads in the y direction
& u; Z5 x8 F; W acceleration ;; the constant that controls how much a car speeds up or slows down by if
+ x; Q* w" N: _; {$ L ;; it is to accelerate or decelerate. B3 }2 g! A; ^ b' L! U
phase ;; keeps track of the phase
1 L5 M9 m" ~) F$ q2 o4 f num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure2 ]" T8 {) ^7 ?8 r, Q
current-light ;; the currently selected light
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;; patch agentsets$ G7 q% @; Y. y }! J+ E; @
intersections ;; agentset containing the patches that are intersections
) o' @ N3 |4 ` roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle* q3 |( C- Q6 Z- ?8 M
up-car? ;; true if the turtle moves downwards and false if it moves to the right
% l( `; A5 s& F9 y wait-time ;; the amount of time since the last time a turtle has moved+ _ I7 n5 r; C7 g; l
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9 p1 {; J+ w4 E0 r3 [( G4 |6 ppatches-own
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intersection? ;; true if the patch is at the intersection of two roads8 Y4 d% X& O( X1 Q# ]$ C
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
6 E9 ~6 B; L* Q& `: E ;; false for a non-intersection patches.1 Q& V- G3 O/ @
my-row ;; the row of the intersection counting from the upper left corner of the0 A2 R: V" p- I" E0 p) J3 s8 F, ]: R
;; world. -1 for non-intersection patches.
! C6 @! s: f8 m my-column ;; the column of the intersection counting from the upper left corner of the3 Y6 y$ t# c+ Z0 Y& a# \
;; world. -1 for non-intersection patches.
1 l0 o) L3 _. g) a5 E) X& N my-phase ;; the phase for the intersection. -1 for non-intersection patches.
! o7 G) S7 \) m1 \/ V# M auto? ;; whether or not this intersection will switch automatically.3 O) h% t+ L2 w2 M
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
1 v& X, k0 q7 W) w& ~;; Setup Procedures ;;. Q" v3 M" S" V
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
9 r/ r+ f* q8 ?3 F;; Create num-cars of turtles if there are enough road patches for one turtle to4 e+ P# Q% V8 ]" ?
;; be created per road patch. Set up the plots.- ?! W) h8 K: ]! W& [' G7 z
to setup
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setup-globals; u: J& v0 E& Q6 ~- L
$ y O/ S% K3 f ;; First we ask the patches to draw themselves and set up a few variables) o; g) A5 T8 }# z5 A1 ]8 N7 z; }
setup-patches
6 F( L w: ^/ q0 `, I) f make-current one-of intersections$ z5 D5 v- Z$ g$ S( H
label-current
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set-default-shape turtles "car"* n4 p, K! z+ i! F: J' U
: P7 h" G$ b9 T: ^2 V/ C+ C$ y if (num-cars > count roads)
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8 k. F# l9 J+ G! e( J7 Y user-message (word "There are too many cars for the amount of "
/ W+ C4 f' V! j g. S2 a2 X N9 I "road. Either increase the amount of roads "
/ Y7 X9 h* l* B4 V+ | "by increasing the GRID-SIZE-X or "3 `5 L# H: ^9 H1 E
"GRID-SIZE-Y sliders, or decrease the "
" s% ]5 S1 }- J# M4 H1 D$ _ "number of cars by lowering the NUMBER slider.\n"
" y) k ]6 u' E$ G1 d) q" J: O "The setup has stopped."): f2 @6 W" f4 |/ p, ^
stop5 C4 q! T. p6 G& F
]
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color+ p9 Y8 K) h+ E4 ?% e5 u
crt num-cars
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setup-cars3 k& c5 @6 X: ]/ J# h1 g9 m
set-car-color
3 f; B: `% n; `! E h record-data
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`' p7 X% t( s ;; give the turtles an initial speed
Q* ]- \# |5 Y' X ask turtles [ set-car-speed ]
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reset-ticks1 w0 Z7 I ?8 X# `" I2 \
end* k6 ]& n3 E; O4 B
0 \, g! I: {' J+ Y2 k;; Initialize the global variables to appropriate values
% P7 A7 C9 O5 `) Rto setup-globals! ?+ r+ A6 F* f
set current-light nobody ;; just for now, since there are no lights yet
7 R% N, c+ E. l set phase 0- A$ e# t* U. b" \
set num-cars-stopped 0
; f( g8 f( x# u, @ set grid-x-inc world-width / grid-size-x( z' i8 P/ ~9 u, d
set grid-y-inc world-height / grid-size-y5 C; a! ~6 v, z& z* _
) p( D5 R9 p3 i8 i2 I+ R ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary' I9 d" ]9 z7 ?* _
set acceleration 0.099+ k) l" S, e! y6 d
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
* d; D' ]1 _( ^, v9 [;; and initialize the traffic lights to one setting
8 P: P6 ]/ H+ eto setup-patches
- p/ c% h. e+ I8 z3 k: L ;; initialize the patch-owned variables and color the patches to a base-color
1 n6 d7 T. v/ e% m+ Q8 v, Y7 {6 b ask patches
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set intersection? false
5 t( f Y! i4 Q' V set auto? false4 y4 O; ?0 _, M0 v
set green-light-up? true
! j" R( Y% u8 Q. S' m3 N: \) k) b set my-row -1
3 k' j* m; z; c" W! i1 P set my-column -1
, u- J6 ?( ^& M+ k) t set my-phase -1! [( X) Y: U% P2 g
set pcolor brown + 39 V# }- F0 b" U
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;; initialize the global variables that hold patch agentsets$ Z' q0 v9 k8 {# @) V, c
set roads patches with+ h% l1 n8 {/ Z, r) d
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or5 F N0 U: w# Y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]! w9 Z, w# A8 J. @- H5 o
set intersections roads with/ {! G) m: T2 x o7 Z0 Q% t
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and2 o# D+ ?) x7 Z! h6 S7 Q7 G
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ] b' k% H5 V, ?/ n
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?
) g7 u* O3 z- Z1 A O set roads patches with
6 O& n* z- g$ R6 x: T! r [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
3 S, P% e: K, x" R. w* S/ p (floor((pycor + max-pycor) mod grid-y-inc) = 0)]: A7 W$ a) D9 ] P
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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