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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。
" b3 X M* a/ B7 |9 knetlogo自带的social science--traffic grid这一例子当中,
5 T# s/ B# I1 \( wglobals
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- c( d% R# V( v3 t% F- r grid-x-inc ;; the amount of patches in between two roads in the x direction! v) [& M6 F! }
grid-y-inc ;; the amount of patches in between two roads in the y direction
. O' [9 d/ p( h6 k; | acceleration ;; the constant that controls how much a car speeds up or slows down by if
, j4 ]. }: w- J2 L* s ;; it is to accelerate or decelerate
! ]8 L: I9 h: g4 Y$ ~; A a' u phase ;; keeps track of the phase) Z( E& V I7 d
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure l! }1 y/ A7 K' m6 r
current-light ;; the currently selected light
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! n9 [2 g) n0 | F ;; patch agentsets% D* Q8 A/ ~3 {9 G, H. e
intersections ;; agentset containing the patches that are intersections
9 r C' v @8 g8 p" i9 P roads ;; agentset containing the patches that are roads
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* G4 q2 E: o# l: [9 i4 o' s# gturtles-own
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1 J) i- K. m# N3 ^3 S speed ;; the speed of the turtle
& ]0 |5 N n6 C- V4 A- A+ z up-car? ;; true if the turtle moves downwards and false if it moves to the right- Y) w) X8 c% L4 a2 Y" O
wait-time ;; the amount of time since the last time a turtle has moved. {7 s' e6 f+ Z( M- M2 a/ X& U
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patches-own
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intersection? ;; true if the patch is at the intersection of two roads, V/ x/ {2 Z+ L& c5 a
green-light-up? ;; true if the green light is above the intersection. otherwise, false.7 o, ~% L/ e u) r1 H3 B: _
;; false for a non-intersection patches.' x8 w- K+ x; P
my-row ;; the row of the intersection counting from the upper left corner of the8 e# `9 X3 c: L- t1 K" q
;; world. -1 for non-intersection patches.; R+ R- ~3 @/ g' `1 B( i
my-column ;; the column of the intersection counting from the upper left corner of the
# l! V. d# g& [" j# v ;; world. -1 for non-intersection patches.
9 {8 L) c; S+ _* i3 K$ q my-phase ;; the phase for the intersection. -1 for non-intersection patches.8 c0 }6 [4 w- M2 j
auto? ;; whether or not this intersection will switch automatically.
$ j/ v4 c6 _) f$ c ;; false for non-intersection patches.
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/ c) F2 W( n$ E; f% ~& n v;;;;;;;;;;;;;;;;;;;;;;' e% u4 t" X5 ~) x
;; Setup Procedures ;;
: S I: {9 ^9 Y: u0 H! L; B) n;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
; U& s; E+ i! @$ G. b" b;; Create num-cars of turtles if there are enough road patches for one turtle to
' k( q6 v9 L6 g9 t3 Y& g* v;; be created per road patch. Set up the plots.
( N5 u3 S& |) e0 [$ b7 Kto setup
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;; First we ask the patches to draw themselves and set up a few variables
* V6 B! v1 Q: q! O- r) }, U/ a setup-patches) R1 e0 m3 ^( P" |8 h
make-current one-of intersections' I+ X5 Y. F: `+ ^& V0 w- P5 R( d( N0 ^
label-current
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set-default-shape turtles "car"! K: k% ]9 S' h8 b1 j3 D4 {" P+ _5 k% @
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if (num-cars > count roads)2 L% l, r3 P; W) f9 s6 ?* e
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user-message (word "There are too many cars for the amount of "
7 q& R7 ~& Z2 g "road. Either increase the amount of roads "
# `( u9 G' j$ B "by increasing the GRID-SIZE-X or "8 k9 `6 z! Y+ l/ b9 {
"GRID-SIZE-Y sliders, or decrease the "! n9 r* B" l; J$ v* _
"number of cars by lowering the NUMBER slider.\n"
2 u/ _5 Q6 O9 v. H1 Q( j% X w5 | "The setup has stopped.")' Q" g" ?4 i$ H
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
5 Q6 D2 I- b: W! u9 u crt num-cars
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3 D( y( B! R. z7 } setup-cars5 Q1 w3 d/ ~5 V/ U. p$ G! S
set-car-color: O+ P5 t: F+ N0 |" o0 ^: N
record-data, l0 Q2 }- z- `% b( ^
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;; give the turtles an initial speed
1 A8 J# H) U( k! K ask turtles [ set-car-speed ]) q7 ]3 B4 O1 V& g7 z* c
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reset-ticks" j9 d! u+ `5 Q |" t$ d
end
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( y6 B8 Y, K. P/ {* _;; Initialize the global variables to appropriate values Z$ w0 N* }; o* K! B9 Z
to setup-globals! ^4 o4 r9 r% d& Z7 S2 z
set current-light nobody ;; just for now, since there are no lights yet! ]: ?6 M$ s6 C+ s" M0 x0 k# L" G
set phase 0
# X& H' v! n: o set num-cars-stopped 0, b5 |: A4 J! t+ X! S
set grid-x-inc world-width / grid-size-x
$ ?" R T/ p7 b8 | set grid-y-inc world-height / grid-size-y# e7 j9 W- }2 h, x+ d9 K5 _7 T+ I
" w8 K5 f% s N Z9 l1 |. J7 m) {. C ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary; m) e5 J( B% H6 c& h" q$ c( L3 E
set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,1 w$ E6 \5 Y8 j
;; and initialize the traffic lights to one setting
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$ x) b6 U" ?; @) {# B ;; initialize the patch-owned variables and color the patches to a base-color
/ {( q6 y+ Y9 ]7 Z2 J ask patches
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set intersection? false4 k( y* Y2 r d
set auto? false/ r4 b4 L6 M5 M2 s. D( W( F" w
set green-light-up? true
2 f: n1 K, W- r! S. K1 }7 M9 s set my-row -14 u# ?) q8 r" [/ R& a
set my-column -1
4 |$ r5 }& Y& c set my-phase -10 h3 U# ?3 r0 j; C4 p: R) r; T
set pcolor brown + 3
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4 H3 U; E) X5 |3 z; ~ ;; initialize the global variables that hold patch agentsets
6 Y' d+ K3 J5 x% z set roads patches with2 L& Y/ {2 z6 Z2 T% j
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or& }5 w/ v0 ~% J. o7 {7 @9 E( ?4 Y4 r
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; y1 E% `3 t2 ~ p/ t set intersections roads with
4 C- a: y" A8 H8 _/ M$ H7 m1 G [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and, K' P5 `, X9 R
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]: Y$ W2 M6 g+ D0 Y7 F) u8 u+ M
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ask roads [ set pcolor white ]
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end: W' A. r+ ?9 c5 F# j3 ?
其中定义道路的句子,如下所示,是什么意思啊?
. B. d. E, k) L' f' V& s set roads patches with4 g) O/ c5 l5 O% `4 g* ^+ u. a: P$ U
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
0 B* r; |1 ~2 n- \* H (floor((pycor + max-pycor) mod grid-y-inc) = 0)]( ~6 }" ^4 ^1 V( j
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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