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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。& d% O ~$ A$ H# J1 y r
netlogo自带的social science--traffic grid这一例子当中,
6 ]- e/ N6 G, j) y! xglobals& y4 t, ^9 D/ k% b4 C3 j$ n
[
5 N( `, l, } L2 C/ ] grid-x-inc ;; the amount of patches in between two roads in the x direction
# ?# q: l) R7 d grid-y-inc ;; the amount of patches in between two roads in the y direction
0 Q+ i4 _& |8 A! p' @2 t0 j acceleration ;; the constant that controls how much a car speeds up or slows down by if
0 u5 l# [$ Y1 @: ~2 d( I- M5 o ;; it is to accelerate or decelerate
4 E3 Z2 _# z# @ phase ;; keeps track of the phase# |/ q+ P* p" C$ I) Y
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure8 E( C. G0 l) U0 e1 s# a
current-light ;; the currently selected light
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1 M9 t: ^6 o; e% ` U3 h ;; patch agentsets( `1 o# K0 ~$ d
intersections ;; agentset containing the patches that are intersections
. R* F: N! l, R& j roads ;; agentset containing the patches that are roads* i' S% n; I t
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turtles-own6 r0 p$ B2 c2 F( S8 K: V4 O
[
" w9 A d- v) \6 k speed ;; the speed of the turtle0 \) o5 `' E- Y' ^
up-car? ;; true if the turtle moves downwards and false if it moves to the right
2 e/ }9 ~/ r6 U( b" D7 u5 C wait-time ;; the amount of time since the last time a turtle has moved; T+ X3 N( O+ l6 t
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patches-own! ^4 F, S* b, D% F: x
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intersection? ;; true if the patch is at the intersection of two roads
7 |# E1 v3 c/ I, n( H5 }4 P green-light-up? ;; true if the green light is above the intersection. otherwise, false.
1 a* q1 K1 B- a, h" ]* s4 W ;; false for a non-intersection patches.. @ ^$ |" {( o. Y+ c
my-row ;; the row of the intersection counting from the upper left corner of the8 |9 [( f* ~& ~* A7 d6 `
;; world. -1 for non-intersection patches.$ R. }) c8 f7 F, \8 F, d
my-column ;; the column of the intersection counting from the upper left corner of the
- z. i5 g2 P3 e; z ;; world. -1 for non-intersection patches.
+ H" s$ w5 ]& } my-phase ;; the phase for the intersection. -1 for non-intersection patches.2 M8 k3 T' d$ I p, T
auto? ;; whether or not this intersection will switch automatically.* X X" K& E* \" r$ [
;; false for non-intersection patches.
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, f3 D* \/ _- \6 s. H$ q. k;;;;;;;;;;;;;;;;;;;;;;+ j0 h( [8 _# b% \% E( z! J5 }+ c0 [
;; Setup Procedures ;;
1 E, i3 S" ^. R* Q;;;;;;;;;;;;;;;;;;;;;;8 O, x# p( }( ?, i
+ ^" Z! y( r( H/ e7 a2 m& o8 };; Initialize the display by giving the global and patch variables initial values.# y+ o% O/ ^8 q$ D$ V6 n
;; Create num-cars of turtles if there are enough road patches for one turtle to0 ?+ _/ X& x h% _$ Z
;; be created per road patch. Set up the plots.4 B$ u3 c: @3 B0 ] m
to setup
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setup-globals1 j* A- Z, k" C7 c& {/ i4 H
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;; First we ask the patches to draw themselves and set up a few variables# r2 ]/ X; T. H3 I, d% J
setup-patches
( S; {+ t3 p, o' [; T/ | X# h make-current one-of intersections5 q# P9 p7 o/ f- D. {
label-current
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set-default-shape turtles "car"
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4 b' ?8 d: Y" |* Q D if (num-cars > count roads)% t! d/ [: w- z
[
; q" l* p# t; }' r. _: l user-message (word "There are too many cars for the amount of "
# S$ j) l) x# k( t "road. Either increase the amount of roads "/ ~: W& D) I: Z
"by increasing the GRID-SIZE-X or "5 V7 {* e+ Y! u! v2 Z
"GRID-SIZE-Y sliders, or decrease the "6 z1 ? m! Z# H) w3 j1 J! ]
"number of cars by lowering the NUMBER slider.\n"# z$ i$ f C. E* @5 t
"The setup has stopped."); f& I+ [: h0 O( w/ F
stop
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% a2 y m) n2 d. r9 J ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color) X( x$ C* ^# y: Z2 ?# F0 L
crt num-cars+ O7 \8 b. h2 p' K* b! o' N6 H
[
: ^" N9 ]( F# N! W setup-cars5 g6 Y# B6 e0 E3 I* m. l. C4 [8 }
set-car-color! V) _( C! c* y( ]" _% M; [6 N
record-data
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( C# }' Z9 h4 _9 C: y# i ;; give the turtles an initial speed0 Q! `8 S6 N- L/ M. W# V) J
ask turtles [ set-car-speed ]) p5 W. s6 S1 A
6 Z+ u3 T! C' B3 F }' r( G8 `( t- t reset-ticks4 N5 \4 C1 \, B
end
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;; Initialize the global variables to appropriate values5 Q. l* N2 q' J' p2 r6 O
to setup-globals$ D0 p; b$ V% e. L6 ~& L
set current-light nobody ;; just for now, since there are no lights yet% m3 c( o8 D5 ]
set phase 0
8 H b, ]) E4 a- x+ B8 \ set num-cars-stopped 0
3 L' f& G3 n* h L; M9 { set grid-x-inc world-width / grid-size-x, q( i' |# T4 b$ \* K _( t! \' g9 ~& m
set grid-y-inc world-height / grid-size-y
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* J% D6 J( i$ s' P# C1 `: c ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary' {( @4 q6 A) \1 P, k! J5 c1 N
set acceleration 0.099
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( [' @; _6 ^& z* C, L7 e' Z1 K;; Make the patches have appropriate colors, set up the roads and intersections agentsets,7 q- g1 _4 U# ~( Q5 P; u* O
;; and initialize the traffic lights to one setting3 u, x# c& d, z* `
to setup-patches
8 f: @. S. Y2 K1 q ;; initialize the patch-owned variables and color the patches to a base-color
8 p, | @: l9 H2 k8 F* H ask patches2 [% I( e: w9 u$ K+ J
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set intersection? false9 ?, c' C. j `% i# N6 e/ n
set auto? false2 q( | b8 N+ \
set green-light-up? true
6 W& B7 P# ` y% T set my-row -1! p9 ~% D2 p) t: v, O7 F
set my-column -1* j8 q2 @/ l; i. w1 S) P. w
set my-phase -1+ v+ v4 m1 [: r* c/ w
set pcolor brown + 3
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K# }0 S) L. [+ c+ Z9 I" ?. ] ;; initialize the global variables that hold patch agentsets7 ~, A6 v' c9 H% D
set roads patches with
) B8 z8 R: D6 {' q" a- i [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! U2 E% f/ F+ ^( c( k5 q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
+ z9 I* m1 i0 _/ g8 J/ Q2 n" g5 W set intersections roads with
; `$ \4 [. I7 y [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
/ \% h4 I0 B! C (floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 y1 Z- g; G1 R# N1 T" V( j
8 T D' ^! {/ o- o! }& M ask roads [ set pcolor white ]" m& W% c7 b4 z* D3 K2 G. P. Q
setup-intersections c G) O, W0 N
end
: y/ G. X" O3 \% Q其中定义道路的句子,如下所示,是什么意思啊?
2 ? L8 X) D) ^# M, q set roads patches with
( q+ g+ c9 R& W3 e* k$ Y [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
+ n% A1 w4 X u9 z& Y) A (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
4 M$ ?$ R7 k# N9 S- c5 m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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