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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。
4 u" _' i; c, c- `, C onetlogo自带的social science--traffic grid这一例子当中,
8 q2 P* {4 w9 m1 a4 Wglobals8 w& \! {3 W, o6 J+ v! `+ b
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grid-x-inc ;; the amount of patches in between two roads in the x direction
& H4 }2 {- x* e% \7 P Y& ~ grid-y-inc ;; the amount of patches in between two roads in the y direction3 z7 X& c7 T, D6 c5 X0 m5 c- y
acceleration ;; the constant that controls how much a car speeds up or slows down by if
+ R1 f. F. Q$ D, Q- v3 o ;; it is to accelerate or decelerate
7 h; U4 h6 G- t$ X/ I @ phase ;; keeps track of the phase
# @$ A/ i& `: F6 n* s7 J num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
& S' ^: K2 n1 U current-light ;; the currently selected light. {5 u# h' i0 w( U8 D, Y
* ~+ M( \6 n* G5 | ;; patch agentsets. R8 A Q7 }4 _/ b% @
intersections ;; agentset containing the patches that are intersections( ?& k: _. D6 J# m1 V# f
roads ;; agentset containing the patches that are roads1 }5 R& s( p4 S) _& v
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m" i2 s$ k9 Kturtles-own
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speed ;; the speed of the turtle
( ? T5 D9 u U up-car? ;; true if the turtle moves downwards and false if it moves to the right$ T+ @% L) T& j, v, g
wait-time ;; the amount of time since the last time a turtle has moved
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. x3 B; ?$ x/ N5 A5 X' Ypatches-own
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intersection? ;; true if the patch is at the intersection of two roads' x/ {7 F6 Y3 S l) x
green-light-up? ;; true if the green light is above the intersection. otherwise, false.: W) O' k! S, f; k7 I
;; false for a non-intersection patches.0 E/ }) Z( Z& F3 ?
my-row ;; the row of the intersection counting from the upper left corner of the0 X' O3 x% h0 o, m
;; world. -1 for non-intersection patches.8 P- s U2 j3 i, ]& t Z
my-column ;; the column of the intersection counting from the upper left corner of the
" o6 H: V. @5 d: \4 f( Q ;; world. -1 for non-intersection patches.
: t* j' g' @6 A/ c I0 ]9 D5 T my-phase ;; the phase for the intersection. -1 for non-intersection patches.6 N+ ]- y% t. U+ y, u' h2 _( C6 _
auto? ;; whether or not this intersection will switch automatically.5 o! p& p- z" M# q% ]0 t; [
;; false for non-intersection patches.* v* o6 X6 j5 L
]
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% x3 U& Q- X( J! W- ^" S& r# J;;;;;;;;;;;;;;;;;;;;;;. j( _/ A9 E* ]& t8 |) Y
;; Setup Procedures ;;' d! {& j! I" F
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.) F$ p4 C# i, j5 ~
;; Create num-cars of turtles if there are enough road patches for one turtle to
. [4 b: L5 W& U;; be created per road patch. Set up the plots.
/ ?3 {2 ]) R; k$ ^) {- G) Ito setup
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5 o, l' l0 ]: H s- X% q. y/ r setup-globals5 T: y2 {6 W3 U6 [0 z( W
" L6 N8 ?* n: P7 p) _ ;; First we ask the patches to draw themselves and set up a few variables
0 @. [( e, [+ H R setup-patches
/ M2 U1 g( Q* A) b make-current one-of intersections$ z3 X4 l+ O4 }
label-current& N( h$ C$ `" |' c5 b/ u
0 J2 @! u+ g1 N" ~ set-default-shape turtles "car"
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if (num-cars > count roads)
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9 P3 c1 Z* W, Y+ n9 l user-message (word "There are too many cars for the amount of "" C# F2 S# k% W8 [; K- d
"road. Either increase the amount of roads "
% ^8 F4 v/ a) b, J4 g/ h "by increasing the GRID-SIZE-X or "
7 }; U" ^. \3 e8 D "GRID-SIZE-Y sliders, or decrease the "
7 p* K+ P6 N, H% ~3 b "number of cars by lowering the NUMBER slider.\n"
, E7 y1 s: Q% m9 \' H3 ~' `) S "The setup has stopped.")6 C. `" j. b- r$ d f
stop3 a0 w+ U9 p7 Q7 [
]
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color& g. R8 Y. g8 i+ J
crt num-cars; N" V5 Q, I5 q0 Q: V: Z- _( \- T
[2 ~' }! ]2 ^- d+ l" ?7 Y; q
setup-cars
. J$ K9 N: v6 }) J set-car-color& L. X: T+ t D$ v
record-data' [+ N U$ Y+ a8 T& y
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;; give the turtles an initial speed; [! n6 O9 M( _# M( ~
ask turtles [ set-car-speed ]) l( r! V" c/ @0 n, P
* A# n! s z' d# g! n. U+ D+ } I reset-ticks( S& |1 r, @4 v+ s3 X, l
end; o9 X2 f0 n' n8 p
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;; Initialize the global variables to appropriate values; y# S7 l7 E$ P" w
to setup-globals, q5 i( p/ i/ P
set current-light nobody ;; just for now, since there are no lights yet
3 J$ ?4 O' D F/ O& |3 V set phase 0# b8 \# C: |3 F- e0 Q
set num-cars-stopped 0
" N' a5 ^2 z4 b5 I set grid-x-inc world-width / grid-size-x% A w' f0 q( \
set grid-y-inc world-height / grid-size-y4 c7 r* P9 q+ s% |4 F9 N. p
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary( H. j0 f, W ^3 b! m
set acceleration 0.0991 d4 ]+ Z- c" J5 X( x) Z0 I
end6 t2 s( i* H! _
0 A, F' U" ~. f! ]2 g;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
+ `1 o4 ]2 Q* w* q$ l;; and initialize the traffic lights to one setting# x; B% N$ {+ _# ~! U+ }) M
to setup-patches
% k, O b2 U/ D& z k2 F ;; initialize the patch-owned variables and color the patches to a base-color
Z W9 `* m2 {0 ?7 Y& h ask patches
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set intersection? false
" M! m# g7 [8 q+ J1 l set auto? false
4 B1 x6 p" E% g C5 L; x set green-light-up? true$ @0 C4 b6 X* w) ]
set my-row -1
; S' Y2 b1 [8 O; f& c set my-column -1
9 s- z) |4 n! @$ B set my-phase -1$ e5 N/ s1 t( y
set pcolor brown + 3: W5 @4 K& ^) D4 b$ T
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;; initialize the global variables that hold patch agentsets
+ q4 k# f7 k, u! j! C. S set roads patches with: }0 ^5 N8 m0 E9 b9 P* y& ]
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' F) `& f; k4 g
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
% i$ i8 ^" R! |6 {- X6 ^ set intersections roads with
/ @$ ^ L5 a) [1 |& q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
3 \6 {& w5 t+ N' ?. a, v4 U (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
# }! m3 |7 H8 } setup-intersections H! _/ X2 V) r( f
end( ?1 ]: E; R* V
其中定义道路的句子,如下所示,是什么意思啊?# a V( N9 ~3 Z, i6 m' q0 k2 K' c
set roads patches with4 J- w+ k9 M! @
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
9 e3 V* K$ L- o* a" ]* B/ ] L. ]+ x (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; H* r7 F: }4 ]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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