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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。
% x" z6 }. J6 r1 ?netlogo自带的social science--traffic grid这一例子当中,
: K# _# d. I) R9 G, j1 fglobals; W$ W5 k( j5 y9 H
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grid-x-inc ;; the amount of patches in between two roads in the x direction4 u" e7 Z7 i! R) x
grid-y-inc ;; the amount of patches in between two roads in the y direction0 [/ k' ?+ U: |9 a
acceleration ;; the constant that controls how much a car speeds up or slows down by if
5 C7 J+ L/ t# I4 s, D3 U ;; it is to accelerate or decelerate2 E" y& {4 W" U; ~( c0 B) ~
phase ;; keeps track of the phase3 Z6 s3 c. i" Y6 `
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
' Y$ c0 G$ F, m2 X6 L1 C S current-light ;; the currently selected light
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;; patch agentsets
h$ m" l5 h9 s: `$ d intersections ;; agentset containing the patches that are intersections
& m! ~+ ]: V: m+ f# @ roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle- y; m% l' ?/ F. Q& S! s* \ T4 e- I
up-car? ;; true if the turtle moves downwards and false if it moves to the right8 k5 A0 q3 A/ _4 f) P. E
wait-time ;; the amount of time since the last time a turtle has moved* A0 n# ?( |9 m" b x3 I8 {+ R$ _
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?$ R7 W/ R8 L! M# \patches-own
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intersection? ;; true if the patch is at the intersection of two roads2 A7 s+ ^, J# \" u' u
green-light-up? ;; true if the green light is above the intersection. otherwise, false.+ i4 a8 M; e# f9 t4 J. e% S
;; false for a non-intersection patches.
* B/ C+ P/ C1 N9 v my-row ;; the row of the intersection counting from the upper left corner of the: @( t ]5 Q# u7 u r
;; world. -1 for non-intersection patches.
8 Y7 h8 ^1 o2 C6 `4 f: ] my-column ;; the column of the intersection counting from the upper left corner of the5 ~3 ^! v6 ?6 z' v. E* i, a
;; world. -1 for non-intersection patches.) n, w* l+ R$ _9 ~* P
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
4 U( _# K4 L/ I auto? ;; whether or not this intersection will switch automatically.
' ^1 P8 h2 p1 t. ]$ Y2 M ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;: T, |/ o3 Q' z. x6 ]( G5 b5 A3 b u
;; Setup Procedures ;;+ h( }, o; Z2 c% O4 M6 K% f0 Q# a% `
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;; Initialize the display by giving the global and patch variables initial values.
+ o9 o& u+ A. R, S;; Create num-cars of turtles if there are enough road patches for one turtle to. N; \. q" C+ z; D% r+ k6 A! v
;; be created per road patch. Set up the plots.
! g' J' w, V/ Q1 v/ L, Vto setup
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( O: f T8 t. E8 i a+ h C; b( c setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
, {# Q' V" z8 E# ] setup-patches, @; H* \5 h7 x: Q6 j8 }3 {
make-current one-of intersections
* `1 A: b* Z* |% e* [ B label-current
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set-default-shape turtles "car"6 Z" T& f' ^* `8 j% {+ f0 y, k
# C- P- I' [- a6 t+ r if (num-cars > count roads)" \) j5 T- m% m# y/ U' S5 |
[
. k. z, V$ m d5 y1 U user-message (word "There are too many cars for the amount of "
, J! y" p, k) K g "road. Either increase the amount of roads "
" {. h6 E$ F% K+ u "by increasing the GRID-SIZE-X or "1 c6 a+ m/ j- b' Z0 @2 D$ G
"GRID-SIZE-Y sliders, or decrease the "
! M; d5 e& f! g! M; v "number of cars by lowering the NUMBER slider.\n"4 m, B j2 x: b" G/ y+ S
"The setup has stopped.")
$ T; l& a- q& q) n' Q, c stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
% m. V! q% p/ ]4 t) F a crt num-cars8 b6 N% X: D. [; T3 c+ `8 w
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setup-cars
( d4 X) e+ C4 |! M( B2 a set-car-color
1 X& {% N4 B; i! ~ record-data
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;; give the turtles an initial speed* u4 L4 z& x4 V s8 n8 {/ N
ask turtles [ set-car-speed ]1 c4 p2 B: g/ \/ d2 C1 u8 s
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reset-ticks
. B6 r! H; x& j$ gend
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9 \6 I. Q- }" T& ~;; Initialize the global variables to appropriate values
5 w8 C2 P- v+ c2 v9 j7 C T5 Bto setup-globals
% f7 x q. q' F7 i, {( y$ L set current-light nobody ;; just for now, since there are no lights yet
1 T: P- ~; U* K set phase 01 l1 m% t" N. N6 P: F3 ~# S9 ^ w3 Z
set num-cars-stopped 0
$ @5 W% A+ V+ L4 l1 t4 m/ F3 R* Y set grid-x-inc world-width / grid-size-x
! f @# {9 [4 k% z' T set grid-y-inc world-height / grid-size-y9 o& @* V+ z/ K H1 M
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
4 K5 ^5 ]3 g3 w set acceleration 0.099
. h" O2 @5 c1 G6 Q/ h' E# ~end2 A! z9 l) H: P* P. X( Z6 j% f( v
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,1 O2 A0 l$ Y$ P, I0 _- B0 F/ s
;; and initialize the traffic lights to one setting' x1 a% w* e; R+ X
to setup-patches
) v3 ?3 R S2 k0 m( ^7 I* w' ] ;; initialize the patch-owned variables and color the patches to a base-color& ^9 I( @& C2 ^* S- u
ask patches
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; O' j" I+ f$ t' q i set intersection? false9 \; N6 l/ \3 `( {2 _+ K6 }7 ?* ~
set auto? false/ D1 ?6 l+ |& A- D
set green-light-up? true+ @& o" ?$ M5 C# |' N- v- `% @/ {
set my-row -11 x# r& p* b# |* y: n
set my-column -1, J' Z/ b, k2 V0 c, F
set my-phase -1
3 A; N! E) T7 G/ A* U2 Z set pcolor brown + 3
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0 M l _' D ~ ;; initialize the global variables that hold patch agentsets O4 ~; q$ ^- ~7 I
set roads patches with0 g' m# Z+ j( \. e: H0 E
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
3 ^5 A! `* B6 g; ?1 U4 H (floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 e1 v: S4 e* `/ i5 f9 i v" @
set intersections roads with+ @2 u7 {9 }5 U- U! B/ \5 J
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
- @* ^, `9 O$ T8 |* A* K (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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0 u8 F3 M5 E/ E ask roads [ set pcolor white ]/ Q H' v; c5 E" A* s
setup-intersections4 u+ S j* D8 G& ^
end! P. ]6 J! \& \/ K
其中定义道路的句子,如下所示,是什么意思啊?
3 c& U6 B! e# Z1 [$ \! S9 s set roads patches with
7 X }8 A. Y/ T$ f0 E8 Q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
& U9 q; F; _) Z/ H, p& n8 d (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ S2 i& @: [7 y2 H" \" A( D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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