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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。8 u" w; z& q. o! @% X _
netlogo自带的social science--traffic grid这一例子当中,, P$ Y$ f: m' \2 K
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction0 H" R7 y+ F( r8 S/ H
grid-y-inc ;; the amount of patches in between two roads in the y direction
2 y' }3 \" \5 e/ k A% @' q acceleration ;; the constant that controls how much a car speeds up or slows down by if0 a2 {% X* e/ H4 N, X2 u
;; it is to accelerate or decelerate& u+ s; C2 ]' K
phase ;; keeps track of the phase
, J& v( i* y( W# r num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
# F& `5 x& e: A: a8 ?, e current-light ;; the currently selected light
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9 j3 b5 p* T4 `; D w2 C3 v) H ;; patch agentsets
: L4 N, O8 Y: T/ H' u intersections ;; agentset containing the patches that are intersections- N+ M: N/ r7 }; e# M& Q0 L
roads ;; agentset containing the patches that are roads5 v4 w# B3 @6 g0 W
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9 s6 X. }7 w! s9 O# pturtles-own
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speed ;; the speed of the turtle) x( Y) N+ N/ V% [( ^7 d8 W% a) g. Z
up-car? ;; true if the turtle moves downwards and false if it moves to the right
f% G+ Y: t7 H6 B! _$ T, q( ^ wait-time ;; the amount of time since the last time a turtle has moved% q+ x4 [3 |5 h5 @! ^# Q% }$ A
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4 j9 T8 B! Z) V% G0 K5 M) Y4 npatches-own. X; B6 t8 f" t& N# H
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intersection? ;; true if the patch is at the intersection of two roads
# L A( F2 A* I' J/ D$ M: O/ U green-light-up? ;; true if the green light is above the intersection. otherwise, false. v) R( f+ T5 S n# |3 q! r
;; false for a non-intersection patches.
! B, S" K7 U% u( m3 t, ~" ^ my-row ;; the row of the intersection counting from the upper left corner of the
: P7 X2 c/ l j ;; world. -1 for non-intersection patches.
% |# z% ^, G# D: p my-column ;; the column of the intersection counting from the upper left corner of the0 \ \& C* V+ a+ O
;; world. -1 for non-intersection patches.+ f9 r, w$ r B7 [
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
I3 D' l f* \! u2 s7 M3 C auto? ;; whether or not this intersection will switch automatically.* _% d+ t1 _) g1 D- O, K& Y! |
;; false for non-intersection patches." u2 I7 C8 ?5 v; n1 `3 y4 Q( j: g+ y
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;;;;;;;;;;;;;;;;;;;;;;
- c! j4 [1 r' b4 K;; Setup Procedures ;;8 A$ G: j o2 E
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
8 J0 s5 M4 e. g/ m& b; j" C8 D9 T6 ~;; Create num-cars of turtles if there are enough road patches for one turtle to
* s0 r% r& E+ Q; P;; be created per road patch. Set up the plots.. J. v% i( _, @) {' m) e. A
to setup
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setup-globals5 V' m6 Y% I5 ~! N- i9 E
, G, c# d0 k2 ?$ {5 a) l ;; First we ask the patches to draw themselves and set up a few variables
- [4 c6 ~/ `+ j4 T6 F; x6 T setup-patches. J3 i! C$ O1 H3 _4 {9 ?( a; [6 t2 t
make-current one-of intersections" H) G Z& R; Q b2 B" H% i( v, O& S
label-current
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4 g2 \' \1 ~- H set-default-shape turtles "car": g. G4 D0 U% S' }2 ?1 d
; b7 Z4 M* D9 @ q if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
* p0 ^6 S- q& @* O, E& D "road. Either increase the amount of roads "3 v& `! \8 w& s C% N/ T1 w
"by increasing the GRID-SIZE-X or "* i1 G X2 O2 U5 R3 t6 J/ J
"GRID-SIZE-Y sliders, or decrease the "$ F$ G' g/ d* f
"number of cars by lowering the NUMBER slider.\n"6 |; D* [, `: m6 ~# h% t
"The setup has stopped.")8 |& Q! `- C) g2 X: w
stop
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- x4 `& k9 y9 A# N. @. I4 Q& Y2 a ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color5 L3 J& \8 S6 e1 L
crt num-cars
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( O+ n, P1 q/ ~' w1 H setup-cars" @; H6 k$ o1 C3 P$ r" u3 M1 @0 R
set-car-color7 s, Y6 g" U9 F
record-data
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; H3 g i& l# { ;; give the turtles an initial speed
0 K& w' D: v( Y+ V; l5 i4 D" H4 a) v ask turtles [ set-car-speed ]0 U( |% a& ^+ ?- T
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reset-ticks" g U0 U; ^1 C: H" j% V# c& U
end* j |7 E* N! l% ?
8 V0 Z9 D: R! I; k K7 a3 g;; Initialize the global variables to appropriate values
+ @; v. H5 i- E. ?: k" @to setup-globals6 ~' z) k: n4 _; s' A
set current-light nobody ;; just for now, since there are no lights yet
$ B6 q8 a4 d9 r) U: ? ^7 |+ M% j set phase 0
) b% I# \( } E x5 K' e4 Z3 f1 v set num-cars-stopped 0/ k& P3 d4 k: g* G7 v
set grid-x-inc world-width / grid-size-x
; x9 q/ v# P% `5 ]. s set grid-y-inc world-height / grid-size-y
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' l8 \, G5 s% I F ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
' x& T4 }' ^+ _ set acceleration 0.099/ E9 C9 L& `+ m& `7 y
end$ M8 g2 y0 i6 ]; q1 y% \3 f" y
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,% r6 L T8 Q: S# d* N' e$ p! Q
;; and initialize the traffic lights to one setting
/ q9 Q( D- O% ?+ q" h$ p" oto setup-patches- M2 n8 J& ^/ O' ]8 B# v
;; initialize the patch-owned variables and color the patches to a base-color
0 d$ r7 F: ^$ a' t ask patches
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set intersection? false6 ]7 p8 {& J# ~4 Z) c* q' g
set auto? false; e- Y: j+ [2 P+ T) l( a* z: m, D/ |
set green-light-up? true- N9 l+ X9 t2 y d
set my-row -12 h( k! y, v* c$ l9 \* W
set my-column -1
r t) w/ O6 V: @) R set my-phase -1
) `- s2 p' t' i1 B/ E0 B set pcolor brown + 3
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! s$ ~1 a5 {. E/ L/ A ;; initialize the global variables that hold patch agentsets$ t* h( p# [8 ^) j+ J
set roads patches with
/ L% t: j" ]2 ]# G [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or+ M# K6 S; _' F% V3 ?) q7 i/ R: k
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]) e8 P- Q. }9 A0 J2 U' C/ b. \7 l
set intersections roads with' u4 b2 a6 B" ~! |, N3 N5 T; V
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
5 m1 n1 d8 @, j7 q3 O4 F& ]/ j (floor((pycor + max-pycor) mod grid-y-inc) = 0)]; _6 O w( {" a
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ask roads [ set pcolor white ]( W# T: b2 N# `5 L" j- ^" b
setup-intersections3 P) h8 a0 d- _0 I
end6 ]# i* F7 o4 j* I) w* _: G5 v4 y' X
其中定义道路的句子,如下所示,是什么意思啊?
& i& q5 S- \+ c: U1 i0 \ set roads patches with
4 w* y0 o% |7 U* H/ g [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or, `: k, P( P2 t5 w1 n
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 C2 J: a; l) Q# w, a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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