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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。) G. b8 s8 v; o5 @4 Y
netlogo自带的social science--traffic grid这一例子当中,. e/ n& F8 z: m5 W9 F& e* U3 |2 G
globals: W1 O1 x$ [# [" x5 G" P% U
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' s9 a( Q2 Y% _ grid-x-inc ;; the amount of patches in between two roads in the x direction
- `' u5 y4 e6 O" _2 A; R8 P" u grid-y-inc ;; the amount of patches in between two roads in the y direction
0 R* p/ g9 ]7 U: S, G+ r) i acceleration ;; the constant that controls how much a car speeds up or slows down by if
$ s# ]' i: l8 @5 ^ ;; it is to accelerate or decelerate; b4 |9 ~5 N% K) [% M1 ^, ]
phase ;; keeps track of the phase
+ }6 `. b2 H- R: ]. q: l num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
* f+ f+ w; o/ e, u- D, c$ H current-light ;; the currently selected light+ V, h3 W$ p3 \3 r1 g
# m" j6 W! ?5 C( u! l5 C% A ;; patch agentsets9 @# a# m8 p3 P- w. m. h# Y
intersections ;; agentset containing the patches that are intersections
6 q+ T8 E- r/ A roads ;; agentset containing the patches that are roads
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turtles-own# G2 ]3 C8 j+ F! p& U4 x& L. W
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; h1 ^2 r8 j. C8 j/ u5 ^6 _ speed ;; the speed of the turtle3 h0 j4 `0 X- Z' p. a& N* h$ j
up-car? ;; true if the turtle moves downwards and false if it moves to the right
. g; {! a$ w7 G0 g i9 a7 p wait-time ;; the amount of time since the last time a turtle has moved1 p2 C' Y+ s+ F* U* a# [( x( r
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" F! Z# i; z- ?3 b& @* kpatches-own
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intersection? ;; true if the patch is at the intersection of two roads
. E- h; p% e3 G, B+ j: b0 } green-light-up? ;; true if the green light is above the intersection. otherwise, false.
4 y1 f7 l) e3 z ;; false for a non-intersection patches.
4 z" e: t" n* a. y" J my-row ;; the row of the intersection counting from the upper left corner of the! x" O6 x% a) C1 w% Y# R% l
;; world. -1 for non-intersection patches.
% T2 W0 y" S( W7 ?7 x9 u& _5 w my-column ;; the column of the intersection counting from the upper left corner of the, r! l7 S% P% M G7 c! n" T/ Y
;; world. -1 for non-intersection patches., Z% B% x( F8 P! k) }
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
8 F$ d* ~4 ]6 V4 x9 B" Q auto? ;; whether or not this intersection will switch automatically.
* K' p; G+ c# q' z ;; false for non-intersection patches.. f7 v m+ A, u: a7 }
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' z# O5 Z+ z( X6 n9 |;;;;;;;;;;;;;;;;;;;;;;. v; j7 m4 S+ t) s
;; Setup Procedures ;;
: ]4 s! J) ?# J;;;;;;;;;;;;;;;;;;;;;;
3 [+ ?1 L+ O: T2 D$ X
+ ?7 ?+ V& ]. y* ]$ Y( V* \8 I;; Initialize the display by giving the global and patch variables initial values.
- ]8 c2 a5 S" X2 p* {2 M: w;; Create num-cars of turtles if there are enough road patches for one turtle to
& Q( y; N+ ^$ p;; be created per road patch. Set up the plots.
6 F; |! W6 o$ Z8 R& K+ nto setup
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* Y% j% R, B$ G, }, b) ?) ^ setup-globals7 }/ j" t* n& j' y7 y' [2 _( X
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;; First we ask the patches to draw themselves and set up a few variables
$ ~6 |, O; d$ b7 L" {: k setup-patches
: S; ^# g; A( G' T8 p make-current one-of intersections
+ q; B* s: t% y label-current/ f2 U/ d [- W. x8 W1 i& M
1 y! p) B4 w. ~, f( V set-default-shape turtles "car"$ q0 ]0 n4 L9 _$ s8 x
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if (num-cars > count roads)
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* |7 P; S# ?2 O) o user-message (word "There are too many cars for the amount of "
6 A; l5 J) a! Y) p) ~- E% a "road. Either increase the amount of roads "* y' L# ?# y8 V4 Z9 M* F4 n3 X" c% O
"by increasing the GRID-SIZE-X or "
2 g0 ~) k3 T1 k" ]; {" D: ~ "GRID-SIZE-Y sliders, or decrease the "
! h$ C2 N7 {2 x$ z' R8 ` "number of cars by lowering the NUMBER slider.\n"3 T, A: R, b7 m; e( ~: U- f5 m' \
"The setup has stopped.")3 K) |5 c$ L: u" F
stop: i+ D6 X _4 L+ Z. c
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
4 C; s' v$ E9 l crt num-cars
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1 E8 }! I. W7 w2 d Q, H7 f setup-cars' \1 R/ k) a- x0 i
set-car-color# X" M+ ` r- @0 ?( h
record-data; G+ [* M6 N6 f9 C# B5 c- F+ g
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8 y8 t- H& u/ @0 R. Z1 \, W ;; give the turtles an initial speed U0 b5 }/ C7 r5 j/ ?, Q
ask turtles [ set-car-speed ]% q. v$ \* }% h: o' w
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reset-ticks
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( B2 n; n: q( m8 V+ w) v H, B;; Initialize the global variables to appropriate values
1 w; ~" T$ f% G( P. b3 p9 Pto setup-globals
8 |* B# _: s: }! j" S* U" O set current-light nobody ;; just for now, since there are no lights yet+ C& `7 R6 ~6 g5 D! {, k, T
set phase 03 u3 v) ^2 Q9 x( ^8 i
set num-cars-stopped 0
: t, V0 O$ _& Q4 L9 o$ Q set grid-x-inc world-width / grid-size-x
7 i) f5 m6 |- X% v set grid-y-inc world-height / grid-size-y. s* M/ c1 f" M- y+ C* W
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
. g7 g' }! V/ f& ?, A set acceleration 0.099
2 u1 p/ H! i5 |% X9 x3 y; nend" K$ R7 h8 o" y+ R1 D7 h2 j% e+ ?4 W
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,6 K" T. e' v2 k H# @" u6 I
;; and initialize the traffic lights to one setting
* D. E- k: G5 u: u2 ]3 Uto setup-patches8 \& w: b5 s2 f5 u# k
;; initialize the patch-owned variables and color the patches to a base-color/ _2 i, ?4 |* u, C# n0 R7 j
ask patches
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5 W. b$ k. D; M* k: y, i set intersection? false. J# b) h" E: i) j5 R
set auto? false
) g/ k1 H0 J" L2 F set green-light-up? true1 `5 @: n0 n- P/ K# C$ O
set my-row -1
. n$ ^/ R$ J. i6 [/ p set my-column -1! i3 o, W+ r' k' f7 u; Q! C" K
set my-phase -1
$ j E7 i6 @% B! s6 H set pcolor brown + 3
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+ b( x9 H4 i3 L* L0 r3 ] ;; initialize the global variables that hold patch agentsets
9 E2 T! z* W0 A# x set roads patches with7 r# S, F% i C$ r6 y0 W$ L/ _
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" ?) A$ X- B4 r( v/ J: B
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
( E% {( g% t# S5 M# R% K set intersections roads with
" x) o2 x$ \; B5 K- K [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
/ M+ u( K) B; E: }/ V- h2 A& L/ m (floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 A8 N% S3 c7 r: v: U
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ask roads [ set pcolor white ]: R0 O7 |5 Q! y I
setup-intersections2 ]5 l2 Z. Z& T0 Q. E& `
end
& O! ]* X/ J F! c( T其中定义道路的句子,如下所示,是什么意思啊?
" B+ `9 m3 f( f6 _( N7 ~ set roads patches with
5 H$ U4 y1 I5 W0 e& y [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% f ^( v. ^2 C! z9 X. o5 r! k
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: k* ]3 w5 F# _& ^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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