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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。" z: o; a5 C" z, c# S
netlogo自带的social science--traffic grid这一例子当中,3 }' ?& w5 U) a& Z6 ]! \6 O
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction0 d: |( k- ?+ o" s. w
grid-y-inc ;; the amount of patches in between two roads in the y direction
4 N/ O% y5 I ^! t8 t! K acceleration ;; the constant that controls how much a car speeds up or slows down by if
* b6 |5 d+ u* T7 d% l% `5 z' |3 U ;; it is to accelerate or decelerate
7 I% i; T7 U' h: D4 w4 P phase ;; keeps track of the phase6 o, L( r; D7 h. L. S8 d* Q+ T( V7 [
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure; j) T4 A7 c* F& n W
current-light ;; the currently selected light
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;; patch agentsets& I$ x/ J$ Y* R2 N" Q3 B
intersections ;; agentset containing the patches that are intersections
& ^& {9 x! o0 F' g roads ;; agentset containing the patches that are roads
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+ R; B4 T3 @% ?# sturtles-own b3 a' h( Z; v/ j& G& A
[
8 i& p% s9 A1 t# k- d speed ;; the speed of the turtle
( l. {2 D+ Y8 s7 ^ up-car? ;; true if the turtle moves downwards and false if it moves to the right. K% o& F# Y$ f) X) U) I" _" Y W
wait-time ;; the amount of time since the last time a turtle has moved2 x& v4 I# L# }9 J0 F
]
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$ U) c/ G- c' i g$ v: \3 S+ o2 rpatches-own% w8 [ [/ a& ]3 D& q5 D
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8 q0 y8 Y! J0 I1 T intersection? ;; true if the patch is at the intersection of two roads
0 g# W0 j, }2 F2 \9 z$ v green-light-up? ;; true if the green light is above the intersection. otherwise, false.
c5 `/ v, V# D+ C ;; false for a non-intersection patches.
6 u6 a" W% [: K3 Q my-row ;; the row of the intersection counting from the upper left corner of the9 J' m9 D! V4 ~8 O/ X3 J, I
;; world. -1 for non-intersection patches.3 ^1 ]$ R) K& E- a6 q( d; z
my-column ;; the column of the intersection counting from the upper left corner of the
. d1 o$ r2 K/ H9 w ;; world. -1 for non-intersection patches.
/ \; w- @& b6 l- o# U& } my-phase ;; the phase for the intersection. -1 for non-intersection patches.
0 Y ?# ]4 P- M8 H& y) R auto? ;; whether or not this intersection will switch automatically.1 l' s4 n# [! n
;; false for non-intersection patches.6 |. f8 m) W d7 L% ^
]
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;;;;;;;;;;;;;;;;;;;;;;
5 r9 Z; f e# \2 O3 d;; Setup Procedures ;;
: U: a9 a C5 |# O;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.$ r5 q5 A8 S$ Z* j
;; Create num-cars of turtles if there are enough road patches for one turtle to
( w7 U. N1 s ~* l% |/ i7 e;; be created per road patch. Set up the plots.
' r* R8 R$ w! G9 P4 a% @to setup
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6 h1 M2 a6 `" F1 O7 M) w setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
4 l* B2 ?! d& s8 z$ Q9 _- D setup-patches3 R! H ~3 F1 \/ M
make-current one-of intersections
5 B6 I, C- h; P2 C( J9 Y label-current
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! ^2 {+ l2 }8 y9 d" D set-default-shape turtles "car"0 V9 f, ]. U0 p5 J
% o# z2 C% Y8 k# t if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "8 j' F8 w8 ?" _1 s
"road. Either increase the amount of roads "+ |+ g9 ?) `' g5 F3 S, w
"by increasing the GRID-SIZE-X or "
1 P( @$ j) W# T# J6 m2 Z: J "GRID-SIZE-Y sliders, or decrease the "2 h7 V ]3 y7 X' R. ]
"number of cars by lowering the NUMBER slider.\n"
7 y" _2 @8 E" e5 Z- d$ K/ n "The setup has stopped.")5 X: T' v3 V- ]: F5 Z; c" R, ^
stop
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4 w- w, _5 K" Z: ] _% O) Z ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color* o4 T8 Z3 U8 Y) ^5 i' N1 X
crt num-cars1 U; l- Z- h& }% U4 u" @
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setup-cars
# O5 t0 b) h, ` set-car-color
8 I8 E- S& S' v: M2 o' m record-data: u9 Y( X% ~7 I3 T1 a% E' b
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1 O J1 u; D3 _- e6 w W' F2 W ;; give the turtles an initial speed: \* e9 p) g& m0 t
ask turtles [ set-car-speed ]
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reset-ticks& C* A- V* D7 H( {. h8 f1 J
end
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* c: }" w" [. W* y5 V1 d;; Initialize the global variables to appropriate values* G. j3 Q- N, ?( Z9 q
to setup-globals: U. y# F0 Z# U. I7 \
set current-light nobody ;; just for now, since there are no lights yet$ O! Z3 B( E& o T* i* \
set phase 05 t7 b! D" x" M* r8 x
set num-cars-stopped 0- M& Y) o- Z; d
set grid-x-inc world-width / grid-size-x
5 j: g0 q& X( j) ~) x set grid-y-inc world-height / grid-size-y
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7 \- K1 N3 X" K) i* B+ O( l: m ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary- T3 `5 }/ u" H% Y/ P* S! m
set acceleration 0.0990 v7 t3 Y6 e% o, @
end' |) N- }7 m% D
* k% y R: G& {3 L# N;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
7 u+ d* I- ]6 g3 {9 R( c;; and initialize the traffic lights to one setting
G; b- N& \; a7 F* v0 m% `to setup-patches
[: f3 k' ?6 @' ~9 N ;; initialize the patch-owned variables and color the patches to a base-color
$ s9 \# X4 q7 r9 g1 x" D ask patches1 C+ o5 p& Y. E% K% i- y
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U( K& x; d3 R# _8 g+ d6 z set intersection? false
J5 ^1 n' ]8 U! w set auto? false% }6 ?& Z" q! e1 D. e3 N
set green-light-up? true
8 e0 T- }) d3 w9 N$ l set my-row -1
( K: p y( f n set my-column -11 j: t# d/ ^1 m* O
set my-phase -1
7 y) [4 L3 t4 g: W; l set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets( K" k, g; K* D: m; M" i" S
set roads patches with
% K. y: \ L: w- m! q; b [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" V! G2 j9 t- v6 c7 O' h (floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 l! u: `1 X6 N
set intersections roads with" \3 ?/ R9 z& s3 i
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
/ r& u* N& C' s7 s2 c8 n (floor((pycor + max-pycor) mod grid-y-inc) = 0)]! T3 ^ ~6 t& b/ D0 I9 U0 Q
1 w( [/ N+ e! b+ T ask roads [ set pcolor white ]) T+ R" ^# x! P6 v" l; T" \! Z
setup-intersections
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1 t: E3 X/ |' J# x9 S其中定义道路的句子,如下所示,是什么意思啊?+ M# Z! y$ }" _4 h/ O* t
set roads patches with' X. }6 \: J$ M. r+ {$ D! V8 w3 v
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 u8 Q7 N+ |2 m* J
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 A) G2 v7 o# k6 l+ {( c- Y& ^
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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