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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。) s* X" K/ N( n6 H5 F& v$ [
netlogo自带的social science--traffic grid这一例子当中,5 ~. f) Z' J. B- @. b
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction1 d2 g; u; k- ]5 {1 \5 {+ ]
grid-y-inc ;; the amount of patches in between two roads in the y direction
/ w; E7 r3 a I% i( |. h6 e acceleration ;; the constant that controls how much a car speeds up or slows down by if! q4 c- S! z8 Q/ ?. S$ d" {3 C
;; it is to accelerate or decelerate8 f; k4 ^8 V7 ~% _- C, r) i
phase ;; keeps track of the phase# ^ h) k' d/ O) D& ?
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
, w) d3 C" a0 n/ I/ Z6 N1 s current-light ;; the currently selected light
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2 |' ]) B5 o' r: L( {* M ;; patch agentsets+ }3 q0 ]3 r) `; W$ @' A' i# q7 F0 ~
intersections ;; agentset containing the patches that are intersections' @9 C& o% y3 L* O
roads ;; agentset containing the patches that are roads% \9 [! p+ H+ G: N" s& O- V* z
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* B- {, v/ Z3 P/ t$ f5 }turtles-own, G4 Z9 w$ u0 I, v+ Z. p! {
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speed ;; the speed of the turtle
5 i5 k% S/ S& Z h9 h8 m7 L! o' ^ up-car? ;; true if the turtle moves downwards and false if it moves to the right
* \ \4 `" O" }/ @: ]2 R+ Z7 C wait-time ;; the amount of time since the last time a turtle has moved
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patches-own
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6 }8 Q3 o$ F T4 u e intersection? ;; true if the patch is at the intersection of two roads: A. y P$ l& O5 D! _% k0 {" O4 [
green-light-up? ;; true if the green light is above the intersection. otherwise, false. i% e. Z* g7 J
;; false for a non-intersection patches.
5 C( o* W3 l5 ?( f my-row ;; the row of the intersection counting from the upper left corner of the5 x4 g2 ?& L" H S
;; world. -1 for non-intersection patches.
Z3 i9 K/ K, I7 V k my-column ;; the column of the intersection counting from the upper left corner of the
2 J% t" D: j$ i# B ;; world. -1 for non-intersection patches.
' c* d& s# j' \- o) z1 Y my-phase ;; the phase for the intersection. -1 for non-intersection patches.
) `4 I, [ i/ N( d: U* N. s auto? ;; whether or not this intersection will switch automatically." |, ]. X( w I5 k
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;- J6 o' Q4 G. B9 o( ^2 }' [$ X
;; Setup Procedures ;;1 i( m( E9 n' d
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.7 u: e4 n/ T: x" {
;; Create num-cars of turtles if there are enough road patches for one turtle to* s' m( O# L! Z& R1 r: d- g
;; be created per road patch. Set up the plots.4 g( E; }4 k* }" d* j
to setup! k- D: x# O' v5 C' [2 R, l
ca
/ z; h5 S! ^) | setup-globals% l; @# R4 P0 B% \$ W
1 P8 n7 Q# j; T; Q& N; s/ ]4 ~ ;; First we ask the patches to draw themselves and set up a few variables
1 L* y$ u- F$ m+ D setup-patches
* h! A" R0 Z5 L" W7 E7 i make-current one-of intersections$ X8 C# S3 L1 X6 Z' N
label-current `/ `$ ?2 ^, D) T+ Y: ^
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set-default-shape turtles "car"* ]. V; |4 `: G: X0 R" q5 j
% m: D6 d4 w& H" F7 K5 z if (num-cars > count roads)! @# H3 y, U/ F/ K6 V4 g
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user-message (word "There are too many cars for the amount of "
# Y! g B, e8 F0 D3 F/ s( l) J "road. Either increase the amount of roads "0 A. w8 K2 ^. M5 A
"by increasing the GRID-SIZE-X or "
% p) [" ^/ [3 M1 G( E3 G0 @. c "GRID-SIZE-Y sliders, or decrease the "! ?! g$ k3 m. f% t$ ^( }6 R; d
"number of cars by lowering the NUMBER slider.\n"' D" C" c/ W/ A- P- b0 A9 c
"The setup has stopped.")
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0 }+ g4 T3 d" {" N ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
( N0 Z9 i7 X) X* U% K8 { crt num-cars: n, p: c/ g3 K
[
9 t8 n3 G$ d' I setup-cars
: T. ^7 O) D4 ? u/ c; l$ [ set-car-color
! b0 b7 u! c/ S7 H9 e* |( q F+ E$ \ record-data
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7 h0 F( Q& U9 F. Q0 D X ;; give the turtles an initial speed/ t; C& ?3 b4 p( L2 K
ask turtles [ set-car-speed ]' O" A t* E* p/ w8 s& Q; W4 v
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reset-ticks8 q' p" I' z+ \+ p6 i) c) @9 k
end
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;; Initialize the global variables to appropriate values% Y) u4 v$ Q! i* J
to setup-globals
& F! [: k4 c# H set current-light nobody ;; just for now, since there are no lights yet) j& A0 k9 z" t b+ E
set phase 0
, k( _0 N) U' I/ W set num-cars-stopped 0% o* T4 D7 |7 ]
set grid-x-inc world-width / grid-size-x8 s: k$ ~# l4 X( y
set grid-y-inc world-height / grid-size-y
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) f. l6 t% P. u5 b ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
# P/ U i d: V% `+ t* P" s1 B set acceleration 0.099& f) G7 @, t9 M$ ]% s
end" f! F% b* G% K9 @$ J2 [$ d% s* Q$ S
. Y( Y6 e/ R- X' ~+ X( Y: Z;; Make the patches have appropriate colors, set up the roads and intersections agentsets,8 [2 G4 |! ~0 f& G. ^0 W5 I* W1 \
;; and initialize the traffic lights to one setting
7 }5 x- T; H+ s1 K' m: [ ]to setup-patches
: _! K8 e* v) z" x- I% h: A4 h ;; initialize the patch-owned variables and color the patches to a base-color; E4 d; N- q" ~. A6 V* Z
ask patches7 P5 U8 M H) L* m
[
3 w: d0 I( J# S% @: m( D set intersection? false0 i( C! ~* x* q6 `
set auto? false
$ ]6 v4 A6 ?& c set green-light-up? true
5 k* E* W" m! i, V1 Z set my-row -1
) o9 x& D- @# I( v set my-column -1% V5 H2 O" p! W0 Q) q
set my-phase -1, { i3 L+ N4 h$ s" T
set pcolor brown + 35 ]; z) o q$ ~' j; b- \# ?5 t+ i
]
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;; initialize the global variables that hold patch agentsets8 {1 h+ ?; f4 p p% A2 _6 r% |
set roads patches with
5 G6 v0 t9 Z8 M& w* H [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or% I' E6 M% n7 O; {4 n; r
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
5 |$ b8 P- w4 k8 d9 T( w set intersections roads with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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/ D) Y. f+ r2 F+ ] ask roads [ set pcolor white ]6 U" }5 A t. d8 M$ k! ~
setup-intersections o# H% r, t) z: X
end2 I6 Y2 [+ f9 g* d. O5 `
其中定义道路的句子,如下所示,是什么意思啊?! z: }+ ~7 r, N) P
set roads patches with
1 G$ I: H* W: w) S2 l. s* E [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
+ n- S) b0 F7 U$ Q5 Z0 r7 t (floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 |1 \. s; ^; F& }+ I$ Z
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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