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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。& `8 B3 u4 S9 W" z: ]% n
netlogo自带的social science--traffic grid这一例子当中,
; h5 o6 d) d* l* x5 x4 Cglobals
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/ p/ o% w' ~- V* ^3 v& M$ N grid-x-inc ;; the amount of patches in between two roads in the x direction
& b- r9 `5 }' E1 W. I; G grid-y-inc ;; the amount of patches in between two roads in the y direction
1 L- a( q) G' x; U' | acceleration ;; the constant that controls how much a car speeds up or slows down by if
( d2 S( [$ X# t+ E* j6 A+ E4 [( l ;; it is to accelerate or decelerate! K u( M/ E# r, C& ]) W7 U6 v/ E
phase ;; keeps track of the phase
8 c2 ]0 ?8 |5 b, }# q/ G num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure! s g$ S' `( n0 |/ n' G
current-light ;; the currently selected light( l5 t/ J( _- x4 ], S
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;; patch agentsets
4 `5 t* a+ _8 L: b1 E3 [; ? intersections ;; agentset containing the patches that are intersections6 u+ E6 v7 \/ x, K& g
roads ;; agentset containing the patches that are roads+ f# |5 h" Q3 o' C) k
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turtles-own
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' m" n6 Y6 K% d. c speed ;; the speed of the turtle
9 H9 L1 U+ I8 k; f5 \; o up-car? ;; true if the turtle moves downwards and false if it moves to the right. K6 T) m: R) k3 F- i
wait-time ;; the amount of time since the last time a turtle has moved$ q+ ^% |$ O" @" A
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads% ~. L: k8 ^4 L* `
green-light-up? ;; true if the green light is above the intersection. otherwise, false.: ~# e2 r2 x2 A$ T; r4 m4 s
;; false for a non-intersection patches.
7 I6 L" s" H* `9 Z( }6 }/ e5 }$ f my-row ;; the row of the intersection counting from the upper left corner of the
; }4 k- L8 G0 ~" t. ~; A ;; world. -1 for non-intersection patches.3 F* k; `7 a/ a" i7 V1 j2 N
my-column ;; the column of the intersection counting from the upper left corner of the; p6 V- e F/ T, N7 D# _7 C
;; world. -1 for non-intersection patches. ~+ @( i {1 [
my-phase ;; the phase for the intersection. -1 for non-intersection patches.. |& h3 Q1 ^7 ~2 N3 _
auto? ;; whether or not this intersection will switch automatically.
( K/ F3 ~! Z7 P) ` ;; false for non-intersection patches.; z% _5 f! _. m6 o% Y' w3 o$ _
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4 |) t/ p" q- m4 F1 V" f+ b- k1 D;;;;;;;;;;;;;;;;;;;;;;
" A: x8 Z- I* H3 Y( e3 A& F& Q. _;; Setup Procedures ;;
1 e j$ W5 U- [4 N0 }( c;;;;;;;;;;;;;;;;;;;;;;# ^3 R F+ I8 N
9 H) ^3 f" r( G" |, Y6 F;; Initialize the display by giving the global and patch variables initial values.
, a5 M" K' h7 C$ T3 R; g/ d! B9 t;; Create num-cars of turtles if there are enough road patches for one turtle to
& K% B5 j M, T2 s s8 [! K;; be created per road patch. Set up the plots.* F) p8 G8 `2 _! X9 a3 k
to setup
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setup-globals
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& H) \1 `: ^; W# z1 S6 ] |: J ;; First we ask the patches to draw themselves and set up a few variables
m) F6 I( y/ B9 J/ u: [1 O6 D setup-patches, I" U2 h: y$ Q( G, G8 W
make-current one-of intersections( Q* ^. e5 M, d1 c- g/ S
label-current* `1 N# @- v9 K; D% }% ]
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set-default-shape turtles "car"
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x; s' d# {. U' X if (num-cars > count roads)( l8 ?, y8 [- `/ F2 ~
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user-message (word "There are too many cars for the amount of "$ l" P; m( R3 [3 N+ E1 C
"road. Either increase the amount of roads " Z+ z: h% t q; c8 j( ]" n
"by increasing the GRID-SIZE-X or "/ q$ Z ?7 x, z: g" R& p3 S! F) T
"GRID-SIZE-Y sliders, or decrease the "
) B) k& G o# W. f" B5 A "number of cars by lowering the NUMBER slider.\n"
" F% |9 h* p6 _' m4 Z( }+ z "The setup has stopped.")
. Y# B1 L8 i, P stop
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9 g4 U0 o9 m; s4 y' k0 K) O, q7 U ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
: m! L' R0 k }& P' ~* E crt num-cars
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setup-cars
; H% Q: v9 L4 p set-car-color, l( \" a% R: f& V2 y" k+ W5 f2 C
record-data
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; y1 a# ]2 W. \" Q- e% ? ;; give the turtles an initial speed; v, _: U$ c7 g: y
ask turtles [ set-car-speed ]- _. f( e; R' ?
/ L0 ^9 e5 }" E9 V* Y4 c+ m reset-ticks
/ E4 y2 R$ x: {: l. Jend
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: Y& f! O5 ` q: j" t;; Initialize the global variables to appropriate values) o" m9 k/ i6 o) Y
to setup-globals' |1 s; b! o0 |3 P7 ]( y2 [
set current-light nobody ;; just for now, since there are no lights yet
4 ?6 a* {( j1 @1 `" ]9 v- Z set phase 0" N& ]% _2 s$ A, L4 p
set num-cars-stopped 0
$ B( y0 x. t8 z! d0 T set grid-x-inc world-width / grid-size-x
& ~8 G. f" q8 ?( e& B set grid-y-inc world-height / grid-size-y4 n, B1 c) |, [ B4 ~8 u' u! N; U2 ]
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
6 ]5 d |. T$ Y5 s! W' C* J set acceleration 0.0993 m$ N7 }3 m# J- M
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,: n9 N) z. @, m E
;; and initialize the traffic lights to one setting% A0 q: |1 m# r! Q
to setup-patches
7 j- [% l. U/ | ;; initialize the patch-owned variables and color the patches to a base-color- ~9 m/ h" e) d3 D: E |# z
ask patches
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4 d( h4 o0 O6 r# C% y set intersection? false
0 X4 ]/ N3 W, [5 c set auto? false/ o5 Z, T u5 F1 \* _ [
set green-light-up? true/ z! z4 F( _8 W" ]/ d3 ], P8 `
set my-row -1
9 o: a1 L7 |* @6 G3 U/ \ D" i set my-column -1; A2 V, Z B) ]+ q* }
set my-phase -1
& S+ t/ t( }& c# _" a set pcolor brown + 3& R, f2 l& b# P1 L: f; [) ~
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* L- A0 s8 |: y ;; initialize the global variables that hold patch agentsets
7 |. M* e _8 V& e0 f0 e set roads patches with
1 S$ Y% C4 K/ ]8 ?' ] [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
+ r! a8 }: Y4 ]6 {( p* v (floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 m$ y% _" Q5 J2 p; ~
set intersections roads with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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' z4 P& E) Q5 X* Z# A9 W) r9 S: B ask roads [ set pcolor white ]. m; m* n m) I! c) L
setup-intersections
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3 x) w$ {+ f) _4 M其中定义道路的句子,如下所示,是什么意思啊?
( d5 L9 N9 N& c4 f8 B4 |4 S set roads patches with
2 w& _3 M, o1 h0 o [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or( D+ f ~( k8 X1 R' |9 q7 k( N* a$ m
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. G9 _; t) Z5 z5 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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