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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。
5 k: l& G; w: _& anetlogo自带的social science--traffic grid这一例子当中,
0 m/ W0 E( R. Q: R j' nglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
' H4 B" u* I* P' Y( g" B grid-y-inc ;; the amount of patches in between two roads in the y direction* V; z0 M3 D9 D6 M7 e
acceleration ;; the constant that controls how much a car speeds up or slows down by if
; V# ^9 a, O2 j ;; it is to accelerate or decelerate' S. h' x' l5 D, K1 M! c
phase ;; keeps track of the phase
0 r: |. O6 U% w num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure) H" {( n- e1 k. x1 }
current-light ;; the currently selected light
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;; patch agentsets. B' i; Q' N; s
intersections ;; agentset containing the patches that are intersections) B, |9 _% P7 |, c
roads ;; agentset containing the patches that are roads7 h* P8 v+ P$ r9 M% {* K- X
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turtles-own+ @+ [/ ^' R! K4 R+ d
[
- h! q# y! V d k; e W speed ;; the speed of the turtle
2 K( n) P$ J' J2 p% s' y up-car? ;; true if the turtle moves downwards and false if it moves to the right6 ~7 g5 {' H8 D9 `# V3 J! P% _7 q
wait-time ;; the amount of time since the last time a turtle has moved
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7 g, ~; ?5 ?: y4 f, upatches-own5 F( U) F# G$ G6 i' [; b/ P
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intersection? ;; true if the patch is at the intersection of two roads
: l1 S0 S$ t$ e# }; L) U green-light-up? ;; true if the green light is above the intersection. otherwise, false.# J' Z0 T& S6 v! N. F$ B
;; false for a non-intersection patches.
% i. ~( A( J% `% p2 x. y- t my-row ;; the row of the intersection counting from the upper left corner of the3 h' [/ E6 k. D5 b8 j
;; world. -1 for non-intersection patches.
, z5 S! I( {/ n my-column ;; the column of the intersection counting from the upper left corner of the
/ n7 t. S* {6 N ;; world. -1 for non-intersection patches.( x" H4 c; ~. d
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
" L# Z0 M6 m1 v$ ]$ b" q0 p4 @ auto? ;; whether or not this intersection will switch automatically.+ E2 p! H5 p7 f1 V7 K2 ^
;; false for non-intersection patches.3 a" k, ^$ Q& K
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;;;;;;;;;;;;;;;;;;;;;;& n7 b6 V" H' M" y! U; H; B
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.; |1 r8 K7 F, Z& g9 f: @
;; Create num-cars of turtles if there are enough road patches for one turtle to
2 V7 Z0 d% ?3 @/ Y% W7 ?* a. w;; be created per road patch. Set up the plots." K# O1 n5 V& O+ f( \) V
to setup
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" A$ X' Y$ l B setup-globals
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;; First we ask the patches to draw themselves and set up a few variables0 P/ c2 e) {1 ^: k r
setup-patches
( U' x; l P) X, s make-current one-of intersections
3 L4 |! K; l: z& s label-current% {& u+ J3 v$ c' ]5 [
; b' i' y* T3 T: g set-default-shape turtles "car"; | P N2 a4 _) p- X8 V' F, w6 p
. [+ u" N2 t7 h# I/ d! Z, h: c: A$ O if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
0 ]1 w; h' b" W, X "road. Either increase the amount of roads "
: Q( b+ J) n; O( Q% A: e" z7 ? "by increasing the GRID-SIZE-X or "
$ E9 N' B$ [ L$ e" }) m) O "GRID-SIZE-Y sliders, or decrease the "+ m6 I$ |9 e1 ? t
"number of cars by lowering the NUMBER slider.\n"! ^0 ]3 _' J6 l9 [( {
"The setup has stopped.")
2 F: |8 N; d* E9 |8 S- E! \ stop
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& {# t: E9 L9 U( {$ g S ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
- L2 S7 @: V5 b% s- p$ N0 f crt num-cars( ]! Y# M3 U. N) R! N+ C
[
: d+ F2 x6 ?+ D setup-cars
! ]7 x" h& B3 m, b: n set-car-color0 P! a6 h7 E0 k" [0 C- d* O
record-data
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% ~4 Y0 ?; Q) v) m ;; give the turtles an initial speed
( K, v$ o- _9 o4 E ask turtles [ set-car-speed ]% @4 ]' L4 z# j" U, b w
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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' O$ L& e- n1 R2 b2 K0 S
set phase 07 W+ K, } y D' b- J1 l; Q* Y& |
set num-cars-stopped 0& ~9 Q# R6 o; E
set grid-x-inc world-width / grid-size-x
% q0 U( J4 V2 ]6 [2 D! ]% L4 u 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 boundary, q8 s4 m. ^5 u @/ y4 d
set acceleration 0.099
5 a, j( Z p& A8 Pend
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
& \/ U( b8 x$ X% a* h;; and initialize the traffic lights to one setting
/ R4 B! Y" t/ v5 kto setup-patches
( p" @ X% ~0 u# G! H. P ;; initialize the patch-owned variables and color the patches to a base-color
/ ~6 X% Q0 R- g9 V" T; t ask patches
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& D& D) ]7 ^2 V/ I: L set intersection? false
* S- `& h, B$ a; g set auto? false
5 Q0 Y4 ^6 m. ?. C set green-light-up? true
% _4 k1 Q6 t) ]1 ~: w" X. N$ M% _+ E set my-row -1
! k% R4 W: _# x* [% G+ ?5 [ set my-column -15 S3 \0 y- p' M3 A7 {( X
set my-phase -1
: k* v) H; C4 z+ ^7 A8 n9 c set pcolor brown + 3
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+ k* a& ^. o! P8 l ;; initialize the global variables that hold patch agentsets
4 i+ w T& B6 L7 Y set roads patches with4 ^9 ?; j# [ n$ L) X; R% d
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: n! }+ ~- \, I2 S# j (floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ `. R; L6 p2 t e) n7 O0 s e
set intersections roads with; X9 A0 \! ~. E5 V; U
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
\5 N- ^8 f$ z& z. l& C1 q% V (floor((pycor + max-pycor) mod grid-y-inc) = 0)]' c; f5 t5 ^" j; w: ?( W
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ask roads [ set pcolor white ]- n5 _+ ?2 B% u. c
setup-intersections8 Y7 z* c' @ q. T5 `/ L m
end. F$ J% Y1 g$ y+ Q+ T
其中定义道路的句子,如下所示,是什么意思啊?$ |& ?$ u2 R0 q0 t& V7 l2 K
set roads patches with- C+ J* T& i, d% B" U
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
5 X8 c: n& u" E9 `7 w (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
5 v9 {* A1 y1 D+ `9 Q: r, \5 j' w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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