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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。6 X/ S! v0 d6 ]- A" d( {* s* _
netlogo自带的social science--traffic grid这一例子当中,
+ L/ ^; G4 z/ Eglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
! O7 n* }1 S' s$ S grid-y-inc ;; the amount of patches in between two roads in the y direction$ ?* ~2 F- ?% [4 b) k' S/ E
acceleration ;; the constant that controls how much a car speeds up or slows down by if
0 p+ z! f# F( b- d8 ?; [! ]7 z ;; it is to accelerate or decelerate
9 H1 D. }: |- r( h phase ;; keeps track of the phase
) h& i8 i! ~+ G b' M num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
& `! p; ^* X3 l* P+ k v5 m current-light ;; the currently selected light
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4 \. N9 j6 B6 d3 ?# X0 x ;; patch agentsets% T6 w5 ?4 g: r* w5 p5 H b
intersections ;; agentset containing the patches that are intersections
& F3 F/ S0 U- L( D' T2 T roads ;; agentset containing the patches that are roads
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turtles-own+ Q9 Q: ^2 P$ w+ c; V; ^
[
, V8 L3 J9 h) s8 W4 e6 G- x) P; o speed ;; the speed of the turtle
, l. D' ~( }( k# V, l up-car? ;; true if the turtle moves downwards and false if it moves to the right
3 x. }1 l" P; g% q5 K# q4 k& s wait-time ;; the amount of time since the last time a turtle has moved
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0 h3 q0 F; k( ~( xpatches-own+ G! \7 L2 u& C/ N! ]0 }! K1 t
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intersection? ;; true if the patch is at the intersection of two roads3 `- p2 Y z2 ^
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
5 v3 V$ \5 e% o" Q' c! q+ U/ _ ;; false for a non-intersection patches.# S9 A: N6 k f. j
my-row ;; the row of the intersection counting from the upper left corner of the
9 j0 z( v- D" S7 P/ S/ m0 I. } ;; world. -1 for non-intersection patches.
3 h9 G+ @5 I9 a3 r my-column ;; the column of the intersection counting from the upper left corner of the
9 L1 x' r$ u. u0 H/ t, Q" n( Q# X2 V3 m ;; world. -1 for non-intersection patches.
. R4 x" X+ z- Q! a5 E' [ my-phase ;; the phase for the intersection. -1 for non-intersection patches.6 |* |# {$ Y Q4 P- e8 Q
auto? ;; whether or not this intersection will switch automatically.
' b1 O8 `9 R2 D6 N1 T3 ]( ]; H ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;- G2 A. ?2 w( Y, l% a/ R! Q
;; Setup Procedures ;;. _' c6 `. w. u2 L ]# d+ J
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
% x# h# r( v* w8 Q. |;; Create num-cars of turtles if there are enough road patches for one turtle to
" h4 v. |( N) i% Q4 |; c$ H;; be created per road patch. Set up the plots. @4 ?: A( n9 T9 s
to setup
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F1 z; g6 B, Q- F5 b setup-globals- b" }1 {$ v1 d2 [) K% L
7 J% C. R1 Y! G. n" | ;; First we ask the patches to draw themselves and set up a few variables
' L4 q3 a3 x) | setup-patches4 Z- j9 U5 ]: W
make-current one-of intersections
6 D0 Q2 H) u8 a0 l7 c' y8 V label-current p/ W. d, L' ?# @7 N
( }; `6 b) Z# w B: t& D set-default-shape turtles "car"4 s' y, j( w# y; X) h+ @4 v
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if (num-cars > count roads)+ [! H' u9 F7 r- X0 T0 T
[
4 J/ F- n; k/ [6 G user-message (word "There are too many cars for the amount of "# G) P1 Z6 B2 u4 U9 O7 S! e- b6 s/ a
"road. Either increase the amount of roads "( b6 J& Z9 l4 w2 t# N5 b3 Y5 l2 e* V8 i
"by increasing the GRID-SIZE-X or "
( z( b* h, p9 ]0 S. c" Q0 y! T "GRID-SIZE-Y sliders, or decrease the "
S2 V0 F6 d" N2 V8 J) R "number of cars by lowering the NUMBER slider.\n"
0 Z5 D$ t; h7 \5 v% U8 I "The setup has stopped.")
% O7 Z* M1 f4 L! E3 V& g) z stop) A; B8 k- `- t% ~, [. j
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' t4 a; N, Q0 n) d8 V/ U R: S ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color% S% c$ `( C' I- k" r
crt num-cars6 m; s* _, _) A, V4 W a- S) ~+ E8 c
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setup-cars
& f+ a! T: p+ v3 H& } set-car-color- Z. p: h: Y+ E. V1 G: O4 Z2 p
record-data+ s" U+ r6 x" I- O
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* ~8 i3 e) O2 \' g9 Q* D ;; give the turtles an initial speed: u% z5 t! | r8 D5 b
ask turtles [ set-car-speed ]9 N2 V/ k' i, w
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reset-ticks
P: z6 k0 Z' x2 K, Lend
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l* f- P4 G3 R2 i: p5 ?: y;; Initialize the global variables to appropriate values, R$ ~- ^: Q4 Q+ ]
to setup-globals3 j$ n" M1 c( h4 A5 B7 I4 u
set current-light nobody ;; just for now, since there are no lights yet
2 p, [4 Y/ D9 N& B5 p: T7 t F set phase 0
9 n. M$ g% v' A set num-cars-stopped 0% Z! K1 v% z' M( e, x
set grid-x-inc world-width / grid-size-x% |0 y1 J$ \+ ^" k
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
9 L$ I- E" M, l( ?$ p: u$ G8 @- t set acceleration 0.099
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,; m% A- P7 L: W& u* O- s/ t4 _! Y7 r
;; and initialize the traffic lights to one setting
8 k8 w. ]$ \9 q4 @! `# [3 Mto setup-patches
9 |. ]: n8 D; v `( y/ J ;; initialize the patch-owned variables and color the patches to a base-color4 J+ { f0 Y9 B1 `' ~
ask patches- p' S" ?& r4 Z$ i% ^8 ]6 ]
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) E7 A7 x4 [) d set intersection? false9 v9 O8 |5 j) l; [. q$ f- R
set auto? false
7 g9 ~* H3 K: N1 m set green-light-up? true
& f! f7 x5 o; ` set my-row -1- X8 T9 x4 `' d% q% l
set my-column -18 j' \5 a) ^6 o# A
set my-phase -12 k E2 L9 S; T0 Q+ c% O+ y
set pcolor brown + 3
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/ R9 [" l$ f0 ^ ;; initialize the global variables that hold patch agentsets
# m+ {5 M5 p8 s# R# A set roads patches with
/ Z6 D1 L* w0 z8 P0 x% O [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
3 q8 g& r0 g4 A+ f- H, A1 P (floor((pycor + max-pycor) mod grid-y-inc) = 0)]. f4 B& t" o; G# `% e
set intersections roads with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
3 f: l3 L. @; P) r setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?
5 s& l c+ }2 A6 ^ set roads patches with
+ q6 d A+ Z0 |. B9 o: Z! H3 u [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or. W# X3 e6 t9 k$ A. ~" j1 ?/ k
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]% ]. g( f4 n2 p4 @
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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