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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。, j$ s3 i3 | x. }2 r3 a1 G
netlogo自带的social science--traffic grid这一例子当中,
/ f1 r9 P4 r% Qglobals; D! y. n% ~ E, z1 ]; O( I1 J5 _
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# C2 G' s( [: H, I grid-x-inc ;; the amount of patches in between two roads in the x direction& d6 F, C; H; U3 O, d4 j3 y
grid-y-inc ;; the amount of patches in between two roads in the y direction# N/ @3 S: a, G' Z) }& y- o3 X
acceleration ;; the constant that controls how much a car speeds up or slows down by if: o" i4 r- y( W/ r, u7 k
;; it is to accelerate or decelerate
$ q! i" b7 f( y6 g* p phase ;; keeps track of the phase _1 w! G7 v" u
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
& }8 M+ Y3 F# @# w& h6 D current-light ;; the currently selected light
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;; patch agentsets
* V) ?5 }# ^0 X; Z intersections ;; agentset containing the patches that are intersections
6 P' V7 ]+ z9 ?# x" i- } roads ;; agentset containing the patches that are roads
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turtles-own
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/ |* ~% K0 q2 n- \% Z& V G speed ;; the speed of the turtle$ F. ?" ] q4 ?) R! i3 l( k
up-car? ;; true if the turtle moves downwards and false if it moves to the right6 K& T/ Q, c+ G
wait-time ;; the amount of time since the last time a turtle has moved& u1 o1 q, x: ~7 P9 |
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6 w/ h0 i& H4 p' \! B npatches-own0 j$ V( n; f: r$ `- i" |" {& }& ^
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intersection? ;; true if the patch is at the intersection of two roads
" d: c5 {* k( b green-light-up? ;; true if the green light is above the intersection. otherwise, false.' _4 \9 M& l) U) H$ l! S
;; false for a non-intersection patches.
- u6 S; t( J' f) t) A my-row ;; the row of the intersection counting from the upper left corner of the! f/ O3 v# V" V# q
;; world. -1 for non-intersection patches.
, T X8 l8 Y( ]$ j, O my-column ;; the column of the intersection counting from the upper left corner of the
: V* v) f( V. y ;; world. -1 for non-intersection patches." b4 P* D( h8 g
my-phase ;; the phase for the intersection. -1 for non-intersection patches.! C0 R) {# t I: E; [
auto? ;; whether or not this intersection will switch automatically.
5 s* r" j9 A# I: K8 b ;; false for non-intersection patches.. v0 x2 n. V; H; `# e+ g+ f
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;;;;;;;;;;;;;;;;;;;;;;8 t+ D5 |- h; j# L' B' r) Z* O
;; Setup Procedures ;;: R3 u9 m+ V* T% Q. c) M
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
0 b6 Y$ D1 K3 F# [/ y. S. |' K% };; Create num-cars of turtles if there are enough road patches for one turtle to
( b2 Q) o) s7 m# T4 @2 t, @$ @/ K- };; be created per road patch. Set up the plots.; y( f2 q, N( u3 U7 E; x3 H2 x
to setup
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setup-globals
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, {% N5 |: M; S2 L5 z# ~ ;; First we ask the patches to draw themselves and set up a few variables9 X5 I" a1 n0 t7 |; `' T' j
setup-patches6 _% v( j8 `. { b n
make-current one-of intersections& M. e6 r) Z- {: o
label-current9 E! _: v% K6 ~1 \& Y( e1 [1 O
* T/ @6 U" C/ y: b9 z6 s' [ R set-default-shape turtles "car"3 X( n5 A+ L5 w% L" p/ l9 {4 s
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if (num-cars > count roads) [* ~, t- ^3 P) J7 ?, l; B: p
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( k/ V [/ y q* V, z' T: s' B user-message (word "There are too many cars for the amount of "' W, o) q0 J5 u/ v3 b* Y
"road. Either increase the amount of roads "4 U. Z, i& l6 H6 i; n
"by increasing the GRID-SIZE-X or "
$ u' t6 t: L" Z- [9 q0 T' G9 b "GRID-SIZE-Y sliders, or decrease the "% Y+ t, _ ^3 J& D( \' O
"number of cars by lowering the NUMBER slider.\n"7 B V0 O8 S" d: A2 |
"The setup has stopped.")' i/ X3 n4 j% A$ ^4 W, e$ h' m. k
stop/ ]. K: Z: d& q+ l, I
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color4 \( P/ t$ I% {& ]
crt num-cars; y: ] ^. Q2 G4 _- ^
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- @; [9 C( B4 i% v' e& P9 S6 E setup-cars5 O. ?2 ^# H& ^% N! o
set-car-color
0 s y8 m" Y U record-data
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7 \7 ^1 s0 V" U/ F0 J ;; give the turtles an initial speed
' g" {* u+ g$ d" v7 F6 q/ R, K, }9 ^ ask turtles [ set-car-speed ]
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7 W, M% y5 Q. [, G8 L T$ {5 G reset-ticks
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, _& H$ h+ i7 F8 t. d& O+ Y;; Initialize the global variables to appropriate values
; @. {# a) |! R2 C4 P9 p" xto setup-globals% F6 P7 P: R& O" L6 R
set current-light nobody ;; just for now, since there are no lights yet
2 S! V; e+ ]" n- }3 s set phase 05 b) m; N( g* d. _) K' `
set num-cars-stopped 0
4 e" {/ U0 [& r m/ L/ T set grid-x-inc world-width / grid-size-x
" b2 ~% M+ C/ t' d% Q set grid-y-inc world-height / grid-size-y
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary3 h4 U% T, O, ]
set acceleration 0.099 W" ?+ J. z2 u1 Q
end2 |/ c8 d$ w7 `) U8 I$ D
2 X" J( z& \& s x8 ], ];; Make the patches have appropriate colors, set up the roads and intersections agentsets,
: @$ I S% @7 K0 n& _' M;; and initialize the traffic lights to one setting5 W) w& f9 Q, Q/ G
to setup-patches4 f0 t# H& E+ w# ~
;; initialize the patch-owned variables and color the patches to a base-color
, P# _, }1 o- h- f ask patches& N% q2 H% `" b: C$ P6 j, U' k
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! S9 V0 g8 U0 L. i, u set intersection? false
4 w3 o; X+ s }$ F9 D set auto? false
3 @0 R, U5 m" a8 E1 z" ]% p) k set green-light-up? true4 R; U, j* a/ T" X* f
set my-row -1$ D4 F* Q# ~4 e3 k- ~+ d; a1 d
set my-column -1' K/ z/ ]# X. {) c# {, X: Z! m
set my-phase -1: @+ Y5 e/ ~4 z1 K( K% q5 l! P
set pcolor brown + 3
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0 C# s5 \+ q& R1 } ;; initialize the global variables that hold patch agentsets( G, T' d: f4 u$ m) [' ^" A
set roads patches with
$ h, ]/ u8 l& Q. D" J7 B [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or9 F' C$ e6 p5 F! Z" z
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]: T2 h$ r. u' d" Z' x3 b0 n
set intersections roads with
# l0 Y) G1 Y+ N* P$ {1 v* h6 S [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and/ P( O! w: v1 x3 M8 e
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
( R3 m# B, z7 z8 c& B) h setup-intersections
9 S. l7 @3 x7 t; O" j2 kend
$ G- a, |- [$ N: g9 t其中定义道路的句子,如下所示,是什么意思啊?: h; K# a# o7 [# [7 j) F) d
set roads patches with
% Y% p8 `9 [" S: Q' G0 A [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
) |: o `1 Y/ e$ _' {* V (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 l: j$ Z& z7 F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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