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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。6 K" U' |/ I( c9 |
netlogo自带的social science--traffic grid这一例子当中,: Y" X) z3 [6 U9 V6 p( W) b
globals; v3 k( N% T: l9 j
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grid-x-inc ;; the amount of patches in between two roads in the x direction
0 f6 \* z$ j0 }' ^ V# k grid-y-inc ;; the amount of patches in between two roads in the y direction3 X! J, B- v/ l2 L, k$ K
acceleration ;; the constant that controls how much a car speeds up or slows down by if2 D2 R, y$ s7 u9 u
;; it is to accelerate or decelerate
2 y6 W2 E" T( w3 U. s$ U+ l! ? a* k& d phase ;; keeps track of the phase7 M1 V) l$ c# i4 `9 W6 }
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure+ x( L- @$ @# N$ D8 X- @% t
current-light ;; the currently selected light
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;; patch agentsets& ]7 ~( F) g1 D# Z' `+ S
intersections ;; agentset containing the patches that are intersections, ~: y& X! A! {1 |- j# B. E& k
roads ;; agentset containing the patches that are roads" a+ l. ^* H: c1 n# B2 d" q8 u
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! a$ J- B+ n+ Cturtles-own- i; p% s: ^/ l
[
1 q5 `2 C1 C1 r4 n9 }4 e/ K speed ;; the speed of the turtle0 d$ [/ l& T5 y4 F
up-car? ;; true if the turtle moves downwards and false if it moves to the right
) z8 [3 {1 j7 d" l: g: c wait-time ;; the amount of time since the last time a turtle has moved6 T/ H" I) S G4 y/ I% M2 [
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9 f7 S$ ~, r2 s5 o- k- Fpatches-own: D" f# n% g; T) v
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intersection? ;; true if the patch is at the intersection of two roads
# }8 v: U5 t: b$ y green-light-up? ;; true if the green light is above the intersection. otherwise, false.1 p# L* w* g8 N2 T
;; false for a non-intersection patches.& ~2 [$ W5 h" m4 }
my-row ;; the row of the intersection counting from the upper left corner of the
, V+ n$ c3 K- h4 X" w o* u% b ;; world. -1 for non-intersection patches." n, L9 q, C0 V/ C
my-column ;; the column of the intersection counting from the upper left corner of the+ R: s- m9 Q9 w K# r- R: H
;; world. -1 for non-intersection patches.
1 ?" r" i. t; W1 T my-phase ;; the phase for the intersection. -1 for non-intersection patches.0 b9 h) q$ U" t6 B+ l
auto? ;; whether or not this intersection will switch automatically.8 ?+ m$ z# d" U
;; false for non-intersection patches.; B( n9 [8 s! D$ f- w
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;;;;;;;;;;;;;;;;;;;;;;; \# b# I& }' X
;; Setup Procedures ;; E# s! v& i# C! Q
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;; Initialize the display by giving the global and patch variables initial values. i+ [5 q, E9 W4 V
;; Create num-cars of turtles if there are enough road patches for one turtle to" x! [0 P% }. y
;; be created per road patch. Set up the plots.
0 U/ A v% r; ^- {% l# Rto setup+ X3 P0 x8 Z/ |9 Y+ Z8 a% q
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables0 h. |8 R( }2 w2 k% t: o- T* |
setup-patches# a) c2 l& M/ V
make-current one-of intersections
* M* i6 w: k6 d2 j( h' J label-current
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9 `9 g+ @# t+ r2 Z: l set-default-shape turtles "car"
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. m" m; K6 G2 q: g if (num-cars > count roads)
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3 a1 I" ~( i6 q6 G user-message (word "There are too many cars for the amount of "
. s @2 u9 I y" F! D" `" U. @ "road. Either increase the amount of roads ") y. |! B' z! H9 @) t7 v
"by increasing the GRID-SIZE-X or " ~7 g1 a* J; V2 }- B. a; i
"GRID-SIZE-Y sliders, or decrease the "
z8 I& B5 f8 _! U "number of cars by lowering the NUMBER slider.\n"6 d! _- M$ O8 r8 N" w
"The setup has stopped.")
9 A. ]$ u8 j# [7 V stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color' x0 f! \8 N* e
crt num-cars
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setup-cars
. h( l, P, }. \1 W; m3 s ] set-car-color! G3 l& z& {9 d0 o/ G( D& ]& q* h
record-data
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$ p# D+ @7 D# E9 \" S9 V1 D5 y ;; give the turtles an initial speed7 Q. O6 Q N6 _6 z, I
ask turtles [ set-car-speed ]. `% O6 x4 G9 V: N5 m
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reset-ticks
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1 H- u, s5 h+ r;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
! Z( l6 H0 |( F: D8 S h0 v set phase 0
1 [. h: M+ _, C set num-cars-stopped 0
8 f/ j' z6 \- Y3 J, O set grid-x-inc world-width / grid-size-x
# r4 o# u6 D/ P$ k set grid-y-inc world-height / grid-size-y
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8 O4 {$ Q/ j8 E0 u: J2 W8 o7 | ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary1 Y- O7 P- K! W# L% J; C
set acceleration 0.099; \! \) M+ W3 N |0 u
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,/ Y/ m7 M. `# ?2 e
;; and initialize the traffic lights to one setting
" M) Y0 ?: i6 o4 h3 P$ Tto setup-patches! Z6 e/ M& e) a6 u, ~0 o B6 ~6 g
;; initialize the patch-owned variables and color the patches to a base-color3 ^4 A M. L; c E7 P, ~/ i: Y
ask patches' o7 f: m7 ]1 v
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set intersection? false
1 ?" c+ x7 V' Q0 J' P set auto? false
" S: m- f2 N2 ?/ \* `) W4 i set green-light-up? true8 N; c( b+ Y& }; Q- s# H
set my-row -1
$ d6 L* \/ }* j& f' e set my-column -1
8 B- t9 f5 ?3 k K& P set my-phase -1+ u- K7 Q3 A {
set pcolor brown + 3
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2 S$ C, e2 [8 U* l' g: T6 D/ i ;; initialize the global variables that hold patch agentsets2 z( k6 c6 Z, c8 U1 R( E% g
set roads patches with
6 e& t# X3 f! P0 V [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
# \+ W" X# X: [& O2 h' o, | (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 b6 B' V Q* X0 q$ R set intersections roads with1 V3 Y$ X2 h6 t: r1 D: Q' T
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
- F$ ]3 Q4 L! Y7 A$ O9 F (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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7 M. l! y5 a( C! B' C" }2 R 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 ~3 j+ b! d8 W" S9 q
set roads patches with! V- t/ v1 B3 t( o+ F( N
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or/ M+ o) A" u/ ^" G
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. r' f8 H" R8 Z* {9 U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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