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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。" _, F9 S$ i+ S2 `- M
netlogo自带的social science--traffic grid这一例子当中, t& l: |; h5 }4 b' G/ V: M& l. `
globals9 L& D$ q& ?# I4 i
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grid-x-inc ;; the amount of patches in between two roads in the x direction' k; f2 y" I7 A
grid-y-inc ;; the amount of patches in between two roads in the y direction
2 _ o) k9 k9 p7 w acceleration ;; the constant that controls how much a car speeds up or slows down by if
) ~9 W. }6 L. ^% C8 j ;; it is to accelerate or decelerate
; x/ |: P! D- r; i# b+ u4 M phase ;; keeps track of the phase; J3 B8 N0 L# R+ N3 @- V
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
0 E' Y! c4 Y4 Y6 a# T8 M4 L current-light ;; the currently selected light+ L6 U K2 a' E
" P/ ^* N6 @- _ ;; patch agentsets
2 E8 M9 Z& }8 u O# k0 w$ v/ a intersections ;; agentset containing the patches that are intersections3 z" m4 ?, o6 i
roads ;; agentset containing the patches that are roads
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; d! s U. V# y' m5 mturtles-own0 q( b! M; Q0 G+ y: t/ b$ f. ^
[
8 ]) g8 ~& G5 O, k& V/ F speed ;; the speed of the turtle1 T5 f X1 I7 y+ P: S
up-car? ;; true if the turtle moves downwards and false if it moves to the right
! u H# h. ~1 R( \2 Y wait-time ;; the amount of time since the last time a turtle has moved. R, e1 H) `6 c+ T
]
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5 f% |9 S, R9 {7 W5 Opatches-own
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4 m% V3 z. P& d ~ intersection? ;; true if the patch is at the intersection of two roads- D) u. z; @4 j
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
/ e9 i! K' I) Q# u8 e ;; false for a non-intersection patches.
* w% ~+ g; e- f7 l" n7 t my-row ;; the row of the intersection counting from the upper left corner of the
4 ^, W! L1 k" Q1 c# s* ~! N5 ?' L5 s ;; world. -1 for non-intersection patches.
0 I. ~* ~* O3 L% P- f my-column ;; the column of the intersection counting from the upper left corner of the/ K# q% T% a3 C2 O/ Z- J; W
;; world. -1 for non-intersection patches.
3 ^0 n4 R& o! Z# E" a my-phase ;; the phase for the intersection. -1 for non-intersection patches.$ g/ d- b& g$ T6 _/ S& }
auto? ;; whether or not this intersection will switch automatically.
3 i. ]4 N$ r4 z( \6 q9 j5 @ ;; false for non-intersection patches.
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: Y1 g, y5 P- J( _;;;;;;;;;;;;;;;;;;;;;;
7 T- p V- ?* g/ j1 T- I& a;; Setup Procedures ;;
+ k1 K4 O1 w( s0 e5 d5 v;;;;;;;;;;;;;;;;;;;;;;- X7 e* k3 ~* c
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;; Initialize the display by giving the global and patch variables initial values.
A7 n7 x9 r6 Z;; Create num-cars of turtles if there are enough road patches for one turtle to
: o; d/ S) C, _5 u# y" _5 H8 |* j( j;; be created per road patch. Set up the plots.
' m; \& O8 W7 H6 E& h1 d6 ito setup# i3 Q5 a. a# y+ X
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setup-globals8 G# V' C% e; O! l0 J& K3 o
: b6 S2 c% I5 u. K9 D7 A L ;; First we ask the patches to draw themselves and set up a few variables. H+ ]4 K/ K4 `4 g/ m( Z
setup-patches( T9 s8 y) c: \/ L0 u5 _
make-current one-of intersections4 u c0 I; y. h4 x& ~
label-current+ N3 u9 i2 @$ J! B% {
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set-default-shape turtles "car"( u. `9 @+ d3 u2 J ^ y1 t5 {1 U. f
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if (num-cars > count roads)
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' X( O1 [1 {; m6 M" s user-message (word "There are too many cars for the amount of "
. s2 W8 @& u. {+ H3 o6 g "road. Either increase the amount of roads "
1 l! D$ ]7 k0 b; F5 F "by increasing the GRID-SIZE-X or "
# f9 q& |' }7 l, ]3 x "GRID-SIZE-Y sliders, or decrease the "0 Z& P5 u8 K |. o
"number of cars by lowering the NUMBER slider.\n"
$ ^1 I3 W) F9 \9 n$ D; y "The setup has stopped.")
- E: D% F; j- e: Q) n stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color6 D0 \) s: j* w: M
crt num-cars$ T; p2 o& h& ~) P
[
. {9 ?7 k, N( R+ W- a( A( I% ? setup-cars
; B' r9 h- M, a7 P& d& P5 k1 e% {$ r$ O set-car-color
8 ?3 S4 T) Y. d, u' P record-data+ p7 A( ?* C2 P- G& M
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;; give the turtles an initial speed' Y- m* T) P# p) Y
ask turtles [ set-car-speed ]
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' C% r- B V' ?! g reset-ticks* x q5 v3 d/ ?7 [- N$ O/ ]' k6 z8 K. [
end
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! e! B9 U7 } b" D( d* w;; Initialize the global variables to appropriate values
& S% I0 x6 |- z G% Z; ?: e8 yto setup-globals- M0 T" w4 h1 K6 n/ _) V* r
set current-light nobody ;; just for now, since there are no lights yet( b, n% A" e5 G' E* Q$ Q5 G
set phase 0
) j+ y U% C% h/ D; _ set num-cars-stopped 0
1 E/ ~% C, Z* {( A( d9 Y2 N set grid-x-inc world-width / grid-size-x4 N- j W' [0 R+ \& j) g
set grid-y-inc world-height / grid-size-y: N" K' t/ J ]+ ^: Q/ V
) e8 L6 o: D. }8 y& s+ p ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
0 S; o a, F0 z+ M2 o set acceleration 0.099
) \" M9 n6 x" J; G' d! A; ]end4 o f( i1 u0 X5 O- `
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
" ?- d+ a' c+ \: W0 Y- \9 M8 q;; and initialize the traffic lights to one setting3 P* _2 q6 j- B: \
to setup-patches
- i, H6 y8 n6 p3 z. d2 z2 j4 |5 L ;; initialize the patch-owned variables and color the patches to a base-color0 N0 C. J6 ^* W9 B5 U# q
ask patches
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set intersection? false5 C" G, s- _1 I; A, J
set auto? false
7 [* C" k2 ^2 k6 d4 l% p" \ set green-light-up? true6 y& X: \& e* B5 p. l w- K
set my-row -1
! z- ]& W/ H0 w( Z# G2 V# {# ~ set my-column -1
- ?4 b- k* ]: y set my-phase -1" H4 c7 p, t: } k" J
set pcolor brown + 3
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' ^5 T& M! v# G9 p4 o: R ;; initialize the global variables that hold patch agentsets
4 u* b% Y6 H/ c( S. Y% Q- n. P! _0 T set roads patches with8 N! D. f! [. [ M$ M/ t
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
2 H, d7 W6 O5 K (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 x6 D, P% N [; {& _* @ set intersections roads with
. B& \% B$ ~1 c1 @; ], { [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
! o) V5 n3 s9 s, `. C (floor((pycor + max-pycor) mod grid-y-inc) = 0)]9 ^+ B! I! ^8 P; U$ j
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ask roads [ set pcolor white ]
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end
?4 Y$ c7 C: v/ `& m# t其中定义道路的句子,如下所示,是什么意思啊?
/ j# Z7 ^- v o7 I0 J set roads patches with/ \0 m: L. a6 P
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
- N) p. c+ {8 U. l (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
+ q2 r% B4 k' Y3 q, W3 {4 Z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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