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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。 U5 r+ t; K4 I% i/ M/ b
netlogo自带的social science--traffic grid这一例子当中,! f# E0 i, q! h% g: ?
globals
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: F3 U4 P, l& w: a Y. h5 I. S grid-x-inc ;; the amount of patches in between two roads in the x direction0 j4 }7 ?% ]7 ?" l
grid-y-inc ;; the amount of patches in between two roads in the y direction
% p7 N J6 N- `/ S acceleration ;; the constant that controls how much a car speeds up or slows down by if& T5 ]/ |) p4 _. w+ ], X" Q# k5 u
;; it is to accelerate or decelerate! ?" B# U+ Z' U6 n) v* ~
phase ;; keeps track of the phase
: m( V$ W8 `/ [( D) @( [, Y num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure( z; h3 q0 C0 d/ c+ ]! h
current-light ;; the currently selected light$ n% ?4 o6 g. L: ?$ b5 G
$ Z7 C# N5 a, U4 L4 D# W6 ~4 w ;; patch agentsets- q Z% i8 N2 `! `$ ~& u
intersections ;; agentset containing the patches that are intersections. V# T: \: D" t6 t, d" E
roads ;; agentset containing the patches that are roads6 M2 E7 |% ]! N4 B9 h! F# {& V4 d4 V* U
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turtles-own
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6 D4 z. H0 K! Z9 w/ F' Z3 t" T speed ;; the speed of the turtle
! `( N$ B% K0 t* |( {0 | R up-car? ;; true if the turtle moves downwards and false if it moves to the right
$ A! N2 v* |$ v: v wait-time ;; the amount of time since the last time a turtle has moved
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patches-own _" V9 j% v, h& R$ E6 [5 Y4 a
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, ?+ e+ `; s/ K" T! h( E$ L" x intersection? ;; true if the patch is at the intersection of two roads% Y% u3 Q d2 z7 r3 {* A7 N/ e3 m F
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
( f9 D6 ] a5 u7 p$ z1 g& l ;; false for a non-intersection patches.
) k& Q9 h$ p- z5 }7 k- b; r' n, F; z my-row ;; the row of the intersection counting from the upper left corner of the% @. R" x% m# i% H
;; world. -1 for non-intersection patches.& ?* W8 z0 k% P6 n! C4 n
my-column ;; the column of the intersection counting from the upper left corner of the: F2 D6 F# u% G( Y
;; world. -1 for non-intersection patches.' ^' |7 e- P6 l" v6 I/ }% X' W
my-phase ;; the phase for the intersection. -1 for non-intersection patches.: ?# n$ g8 ~9 a& c' h+ R
auto? ;; whether or not this intersection will switch automatically." ]/ O d' R+ q- X! r! C: M [) F
;; false for non-intersection patches.
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% X% \$ U' x' v1 H% D! U; d5 ^6 \4 M;;;;;;;;;;;;;;;;;;;;;;2 U I9 `3 Z( g3 K P( z, ?
;; Setup Procedures ;;
5 `5 z' ]! f) S& t;;;;;;;;;;;;;;;;;;;;;;' E5 O4 O8 [+ H6 o( Z; B% {
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;; Initialize the display by giving the global and patch variables initial values.' J& Z' T% t1 X- k* ?' _ l3 \
;; Create num-cars of turtles if there are enough road patches for one turtle to
. ?8 j0 Z& _- \; T; E: g;; be created per road patch. Set up the plots.
* b0 ]: }* o+ R) F7 xto setup ^: _( a, M# [+ h) x1 ]
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setup-globals2 N! ~6 n7 |* x' c
$ F! D4 ]2 z" Y% m ;; First we ask the patches to draw themselves and set up a few variables
% F* Z- Z) Z$ [, @* p7 `; ] setup-patches
" \( k% T5 \$ s# G6 U g- p8 Q make-current one-of intersections# Y: E5 z! L$ V3 w
label-current
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$ ?7 v- l% z, X/ m; o8 u/ ^! [1 C U set-default-shape turtles "car"
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( @( C9 T$ y# L, C. a3 L' H if (num-cars > count roads)& \. H9 b" L$ ^/ p$ R$ J
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user-message (word "There are too many cars for the amount of ", x) E, X6 v8 j; B6 d2 r, \
"road. Either increase the amount of roads "
/ q+ k( j& {) q1 K" K- D "by increasing the GRID-SIZE-X or "
3 ^1 |5 `2 d+ O, G3 O "GRID-SIZE-Y sliders, or decrease the "
b T2 ]' C ]5 t1 K# m j4 Y& l# o "number of cars by lowering the NUMBER slider.\n"
; N) |4 ?, _& ?- f9 _ n( a "The setup has stopped.")
0 l+ R5 s9 J' ^" ~2 O stop; i4 v. L7 t$ A% e, p. R9 Y1 O
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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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2 i9 t; D: t; q4 j: B; C setup-cars0 X# R6 ^' y: U
set-car-color
+ F3 a9 }' j9 P8 a+ A3 A record-data
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;; give the turtles an initial speed' b# _; Y9 W2 m) c) T
ask turtles [ set-car-speed ]
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reset-ticks
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;; Initialize the global variables to appropriate values* P! L T6 q# C/ y* x
to setup-globals
- i$ H8 x2 p- `/ Z; ^1 b set current-light nobody ;; just for now, since there are no lights yet
+ ?: D( G" Z9 s) G set phase 0
/ e! r! U) t: n9 J4 q* x" h, b set num-cars-stopped 00 n: M! a2 i; j. Y) `& _2 H
set grid-x-inc world-width / grid-size-x% _. _8 s. w& u* ?" j# k
set grid-y-inc world-height / grid-size-y
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. q/ C& F; B; j" J/ B* v ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary, Z$ s. B5 C: k, ^! @
set acceleration 0.099
" e; k" L/ T0 }1 Uend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,4 O& u! |2 [( C# O# I4 }8 x) |/ N: a, ~6 P
;; and initialize the traffic lights to one setting
: {1 o8 f" i* G. Hto setup-patches! \. C1 Q$ Y$ j3 H/ v' `
;; initialize the patch-owned variables and color the patches to a base-color! y& I8 C4 N3 N
ask patches
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P! y) A4 J3 j" ^# D set intersection? false5 x6 l9 b/ e1 q0 ?" W6 K7 |
set auto? false
1 q/ Z$ G( y3 l* l1 l* N, z+ \% E set green-light-up? true$ R' W) }. _* J5 V- b
set my-row -1
2 [' F6 j: \/ c- Z; y$ a. E# C3 | set my-column -1' u. C2 _: Z3 `+ Y$ n. c$ |+ b
set my-phase -1
& g1 E3 l( L; W" o- X set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets+ Z1 @ m: o4 ~
set roads patches with
7 @ e3 F: I& A2 n [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
, n+ I0 y* N1 m# R4 b, G0 D9 Y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 \4 v5 V9 {; N" L4 z set intersections roads with
( H) ^9 W, s" g3 ~: z, \& Q2 b' ~ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
3 _% ^* M5 j0 ?( h: V (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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其中定义道路的句子,如下所示,是什么意思啊?
; @5 H/ g! k# b+ d+ k3 b- E set roads patches with
. ]: h7 ^: U& }' t [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or! o- ^* b D! y! x! ^
(floor((pycor + max-pycor) mod grid-y-inc) = 0)], E5 `5 o# X( N4 }! u8 T
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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