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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。
. C, x, `% P0 X# ?* p; qnetlogo自带的social science--traffic grid这一例子当中,
& c: O0 n h0 @4 `. Mglobals: }- \; u8 C5 Q- S) _8 O5 e v
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0 M n7 V0 ~5 L& n# B4 u% S0 ~ grid-x-inc ;; the amount of patches in between two roads in the x direction0 u. f" y' e; z' `2 o4 F, e
grid-y-inc ;; the amount of patches in between two roads in the y direction7 Q8 b" Y5 t3 V
acceleration ;; the constant that controls how much a car speeds up or slows down by if5 x) x+ Q6 G' f& p4 w" ^
;; it is to accelerate or decelerate3 G2 m ?0 T/ n0 R
phase ;; keeps track of the phase$ i: L6 A' m+ h; ]% j, m
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure, ~( m( [" X4 h/ P8 I: ] M
current-light ;; the currently selected light
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;; patch agentsets
# _) f8 }, P- Y0 e) E intersections ;; agentset containing the patches that are intersections) B; x; u/ f4 W4 j [
roads ;; agentset containing the patches that are roads. _- ~6 ]' N5 h4 h
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. q7 v7 O0 j: _" L9 Dturtles-own4 X! B* k3 z. e5 Q k
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speed ;; the speed of the turtle
5 p% M8 n& D8 B) E8 f8 J( S up-car? ;; true if the turtle moves downwards and false if it moves to the right
% I# l6 H( D) I2 ?) ~0 a wait-time ;; the amount of time since the last time a turtle has moved
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patches-own0 ^- K& E, Q/ w4 F% _
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intersection? ;; true if the patch is at the intersection of two roads; E, I0 O& R$ T4 k
green-light-up? ;; true if the green light is above the intersection. otherwise, false." @$ W! k' t$ k& |$ q
;; false for a non-intersection patches.. K' X( n6 _3 w) X2 p( y
my-row ;; the row of the intersection counting from the upper left corner of the
" c. H1 t8 Q1 H ;; world. -1 for non-intersection patches.+ P+ q. Y1 @* n3 b
my-column ;; the column of the intersection counting from the upper left corner of the7 o/ o; w5 o2 ~. H8 ^
;; world. -1 for non-intersection patches.. f2 k- B, S' Y1 Y4 |
my-phase ;; the phase for the intersection. -1 for non-intersection patches.2 D8 v) r5 v1 w6 T2 l, e8 R* P
auto? ;; whether or not this intersection will switch automatically.
' C+ s' c6 k+ ?( k; j5 a ;; false for non-intersection patches.. h# f2 }8 i/ ^& y
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;;;;;;;;;;;;;;;;;;;;;;
, Z5 B; w- w* D" Q g; V;; Setup Procedures ;;
8 n! D3 |* N0 A. ?: \2 k% P;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.2 m( |3 r1 j4 H1 U
;; Create num-cars of turtles if there are enough road patches for one turtle to
; o; W9 _1 d! k& i! q( M;; be created per road patch. Set up the plots.
* N. Q- F+ Z. ^ o; L/ Uto setup: k7 R9 h1 n/ V
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setup-globals" M4 S8 z2 p( o) a! A( B$ U' V1 t. N
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;; First we ask the patches to draw themselves and set up a few variables
* z. N+ K* l- f+ h. Q+ w( Y# `' c setup-patches% `0 R9 R" R; ~% f
make-current one-of intersections
" g: G" r- \7 [6 B- x3 G label-current; R* t7 \0 e( |) y+ T
' u8 C; i& F5 r; q! m set-default-shape turtles "car"
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- W8 w* s$ Y- T2 t4 |9 n# Z if (num-cars > count roads); [$ a g5 X1 l3 k! z' r
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7 o6 l( E5 A8 K9 l6 p user-message (word "There are too many cars for the amount of "' A4 C! k3 s$ e% m) S" i
"road. Either increase the amount of roads "
. B! `: [- }/ q! x% U5 H X4 } "by increasing the GRID-SIZE-X or "
; ]" l; @. T k' [# Y4 V "GRID-SIZE-Y sliders, or decrease the "# z. { O- n3 L' u0 o
"number of cars by lowering the NUMBER slider.\n"
6 R& K5 ?* t' s+ _& {; w "The setup has stopped.")
/ Y4 T5 K* Y4 h- a& J& X0 Y stop
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5 L0 ~4 n3 N* |# N$ W( n T/ P/ N ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color7 f& k7 G$ ]4 N- T" ]7 \
crt num-cars! t* q$ u) ]$ s* I5 \
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setup-cars
2 Y& T' v" s0 s+ C ? set-car-color' q' o% m* t. O' p' c! W
record-data7 B# z$ x3 f3 m) s0 B. H
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;; give the turtles an initial speed& \2 S3 B" f! [
ask turtles [ set-car-speed ]
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reset-ticks
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;; Initialize the global variables to appropriate values) R( C }$ x# G
to setup-globals
$ ^! G& Z" N3 [ set current-light nobody ;; just for now, since there are no lights yet/ u4 L3 |, S! O& d% Z) z s
set phase 0
6 x' X" @' s) d5 }9 I- \, ?& n' w set num-cars-stopped 01 R3 ~- j* Y& J! x9 Z
set grid-x-inc world-width / grid-size-x
/ N6 o! H8 e5 D set grid-y-inc world-height / grid-size-y, K( n! X# o# k/ ^$ Z
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary5 l" e v% ^6 d0 j# Q% n: s e5 x' ]
set acceleration 0.099
0 d; p7 B" J6 r$ x/ Rend* X8 i& d; G M! w! X0 W2 M' i) j
2 Q* d% `# t/ d8 s8 c9 C4 s% ]2 b;; Make the patches have appropriate colors, set up the roads and intersections agentsets,+ K4 Q8 [& x: r" t8 M* d
;; and initialize the traffic lights to one setting8 F) J! u0 s( B. t" F3 a- g \
to setup-patches
+ o- R! w/ Q1 V ;; initialize the patch-owned variables and color the patches to a base-color' a" @* Z0 D+ f! b+ w. R. K) t
ask patches
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( H6 k. x! ^5 T/ u8 }" C set intersection? false6 Z' e' a7 X! }# @
set auto? false
( Z: @. S7 @5 o' t( _7 C6 l5 R9 u set green-light-up? true
3 y9 P; @1 O7 d' e- r1 }! G set my-row -1
# Z. T( I7 \( X set my-column -1$ a: }) K; B& R( h# }2 q
set my-phase -1
! u/ E! n; `# Z, _2 L" n7 j. M set pcolor brown + 3
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2 U% K0 j/ D* R9 \1 w. b ;; initialize the global variables that hold patch agentsets+ G9 Z1 t! a% ^" _0 U1 \& p! k
set roads patches with
/ F+ h; ~* h, z7 i# Q* t* ] [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or$ [- u' U Q+ E: A( o
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]* G+ G8 U' q2 @
set intersections roads with
% o) r& @& r2 h9 E [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and' S7 A# y6 F% F3 a
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]! }$ Q" h2 h o; k4 T c1 w
setup-intersections1 Z6 x4 `) R2 c x; E# K
end- X& d* z3 h ~( y* E, K/ Y0 r
其中定义道路的句子,如下所示,是什么意思啊?( X# f& _5 x7 S/ D
set roads patches with
5 F! t7 Z2 Z% ` [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: Q$ @% x( q. ~9 N" G9 C, a8 x (floor((pycor + max-pycor) mod grid-y-inc) = 0)]7 y) D* K' P+ K* K
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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