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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。( C3 j c0 z7 B- r$ J$ d
netlogo自带的social science--traffic grid这一例子当中,- P$ Z! q+ Q8 }) F
globals& F' G4 ^: u! ?: J
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grid-x-inc ;; the amount of patches in between two roads in the x direction& G& Q! p; B. j- X. f7 M. O) ]
grid-y-inc ;; the amount of patches in between two roads in the y direction2 F, Y+ Q( ~8 {& [) y p( X
acceleration ;; the constant that controls how much a car speeds up or slows down by if
0 f8 y" L1 U: ~1 G4 f# m; [ ;; it is to accelerate or decelerate
" C: Y: R& u4 h) U6 u2 ?) _ phase ;; keeps track of the phase0 y: u) W$ E+ A
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure) A0 a6 ` Q2 i1 e2 `
current-light ;; the currently selected light2 E3 e7 N3 Z5 [3 a; i+ S( \1 ^) o; w
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;; patch agentsets
9 p1 H7 o; f U P; i2 k6 U intersections ;; agentset containing the patches that are intersections
; ~* ~3 g+ C0 b6 H/ I7 S roads ;; agentset containing the patches that are roads
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turtles-own
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# R6 u/ n, R: y+ H2 u speed ;; the speed of the turtle
5 ^, ~6 D5 G/ e% D; u up-car? ;; true if the turtle moves downwards and false if it moves to the right& @: i1 u G7 L6 E9 v
wait-time ;; the amount of time since the last time a turtle has moved
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1 _' ^3 {5 Z4 t9 ?patches-own
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intersection? ;; true if the patch is at the intersection of two roads, J8 h# e: A- P' D: }. X7 Y
green-light-up? ;; true if the green light is above the intersection. otherwise, false.. ]. W) z) Z, S4 l
;; false for a non-intersection patches.2 v. z6 V {3 W5 i
my-row ;; the row of the intersection counting from the upper left corner of the# s$ |- z8 O1 I- d4 ]& K4 V0 k) N
;; world. -1 for non-intersection patches.
5 W4 s( w! ^& h$ ^8 w$ R my-column ;; the column of the intersection counting from the upper left corner of the
) m% z' K8 c- T+ P6 {4 u ;; world. -1 for non-intersection patches.
0 P4 b {/ ]$ T$ e my-phase ;; the phase for the intersection. -1 for non-intersection patches.+ a% F! S; y* \4 o7 R
auto? ;; whether or not this intersection will switch automatically.
1 m" @/ N0 q% n ;; false for non-intersection patches.
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( G9 W) t. j4 E' P" U;;;;;;;;;;;;;;;;;;;;;;
( o) E9 e- u9 W0 Y+ K;; Setup Procedures ;;
9 z& p$ Q4 b4 F' |/ W; g% R0 k;;;;;;;;;;;;;;;;;;;;;;
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! c2 p/ N( Y3 |8 q;; Initialize the display by giving the global and patch variables initial values.8 v8 E; O& {& G* e
;; Create num-cars of turtles if there are enough road patches for one turtle to2 K( [4 g4 i) Y+ _( ^
;; be created per road patch. Set up the plots.
/ c6 X/ a4 c' ^* R. zto setup7 A4 y9 Y K8 ^% |" y3 K
ca
# @3 p) B5 A( [1 y% G* b" e' E- b1 ^+ L setup-globals
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;; First we ask the patches to draw themselves and set up a few variables0 C/ s; T5 H. d9 A7 l4 i
setup-patches
& J; m0 I+ D" T0 b3 T make-current one-of intersections
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set-default-shape turtles "car"
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( o, ~4 ~. F- z. F4 }5 q if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "/ x7 E1 y$ i- I( B7 J5 M
"road. Either increase the amount of roads "4 ~& P% Z5 j! s8 z: j% ~; w
"by increasing the GRID-SIZE-X or "
; }2 x9 L* F( P& q M$ s8 ? "GRID-SIZE-Y sliders, or decrease the "
' B2 H1 l6 J3 Z' \ "number of cars by lowering the NUMBER slider.\n", i4 j$ L: r# R W" ]5 e- Q) o
"The setup has stopped.")
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color3 q* ?& q B' W3 h
crt num-cars
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setup-cars
3 [9 j4 ^; z% f$ w2 q1 x. V/ J set-car-color
5 r' k. R! n5 ?5 S* N9 p R$ Z. z record-data
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;; give the turtles an initial speed
, o0 K! X4 L3 U! \- r' j8 Q. b ask turtles [ set-car-speed ]2 k6 a/ T% ~) k8 Y' g2 x
6 @6 ^, j1 s. ]* i2 B% L reset-ticks
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;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet
8 N) }; o( f5 q" E. Q set phase 0! K! F4 ?$ q( U5 d$ j
set num-cars-stopped 09 T ]) x/ u* @0 y9 v% l
set grid-x-inc world-width / grid-size-x" F* R7 y& O3 Y& A7 I: X- j9 {6 X8 N
set grid-y-inc world-height / grid-size-y6 I, F" r3 o5 |0 ?# z, ?
/ E; j2 I/ S5 h# ^ ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary2 p( a: S9 z$ ?
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,4 b! F# \% {& n* k6 C
;; and initialize the traffic lights to one setting
6 W8 U7 B5 H5 n# w$ _/ l) s& ato setup-patches. Z% e1 j+ y b# H; T
;; initialize the patch-owned variables and color the patches to a base-color
9 ?1 G4 X- g* z/ C! |, O ask patches2 L/ d+ C3 D: L! v" z' W5 z
[
, r/ g- J0 I8 g4 q4 I set intersection? false
! J' ^) N* y$ F5 B. f9 D set auto? false
8 m- p0 O+ }! ?4 Z set green-light-up? true% j' ^9 I9 e# W8 P
set my-row -1. R3 O# k$ i) Y) [8 Q
set my-column -1* O t. n2 p4 t! D( j2 g
set my-phase -11 {% m5 u+ }4 c* _1 d8 h
set pcolor brown + 3& O& H n2 t8 q/ U1 m( O
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m4 ~7 P8 i% t ;; initialize the global variables that hold patch agentsets7 f) w1 ?5 E, `
set roads patches with1 F l/ v, }$ E* g& R
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
& N) V1 `8 r4 c' ] g. ` (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. N) v5 Z% k/ Q6 n% O set intersections roads with
3 m* ~0 N9 j8 j) e1 M$ n [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and) D& T" C% S0 c; T+ s3 C
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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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?: Q- E1 \* x* _% B
set roads patches with
8 V2 ?: Y: Y3 k% v [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! [( y0 ?9 ?/ W) ^4 ^" u/ V (floor((pycor + max-pycor) mod grid-y-inc) = 0)]- ]# h' ]+ C5 T( L
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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