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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 `" A" r( L# O- N
netlogo自带的social science--traffic grid这一例子当中,7 i F) H5 x0 l% ]( o7 ^1 a
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
& s2 F. w$ M) G# v2 v grid-y-inc ;; the amount of patches in between two roads in the y direction3 a( G8 @, A# n: l
acceleration ;; the constant that controls how much a car speeds up or slows down by if) O8 H: S- X% p V* H
;; it is to accelerate or decelerate
% @. r" j5 Q$ r, t/ E H: d phase ;; keeps track of the phase% p* x6 \' a4 i w+ k
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
$ n% ~$ V! v$ X4 J current-light ;; the currently selected light! `9 ^9 n4 P! }: ^; P) s/ s/ R9 N
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;; patch agentsets
! u. ?) s7 | V |4 k/ z w intersections ;; agentset containing the patches that are intersections
7 F, ~, x5 ~4 ^* x# e roads ;; agentset containing the patches that are roads
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turtles-own
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, O: z4 C7 a4 V1 n/ h6 }; l speed ;; the speed of the turtle
5 |5 E, w% j3 H$ [9 D& F+ M up-car? ;; true if the turtle moves downwards and false if it moves to the right5 z0 D2 h% E5 L, X; h8 ^
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own( |2 W+ L4 V! c& W! U4 i
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intersection? ;; true if the patch is at the intersection of two roads- x% y+ Q+ a- b3 w1 Y9 r9 v" _7 x
green-light-up? ;; true if the green light is above the intersection. otherwise, false.' U' r$ N( z5 Z$ j
;; false for a non-intersection patches.( J& T, X4 t( \& w W. b8 E. n; m+ ]
my-row ;; the row of the intersection counting from the upper left corner of the
: {: H( {& J$ I$ J" N ;; world. -1 for non-intersection patches.
$ E+ s7 Q4 v) ~, K1 t1 Y my-column ;; the column of the intersection counting from the upper left corner of the* Z6 ~- J; \% V: B$ [! o1 X: T
;; world. -1 for non-intersection patches.
# v9 ]3 p6 p- N0 _" i8 x' S my-phase ;; the phase for the intersection. -1 for non-intersection patches.
7 Z- ^" ~2 O# N: F. R$ v auto? ;; whether or not this intersection will switch automatically.) `& K% t8 A& b
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
. u" u1 l5 B7 ^, m: f9 c;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.- E# e/ W( k, D, Q+ u0 x) K
;; Create num-cars of turtles if there are enough road patches for one turtle to
4 `7 u& `" V$ I$ s;; be created per road patch. Set up the plots.
( Y7 }4 U2 h: R4 e3 G4 }2 p/ A% tto setup
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# K, h$ ~% J% s- r setup-globals: q/ R, ?' A2 I1 ? M6 K
/ U' x3 _% r$ y ;; First we ask the patches to draw themselves and set up a few variables- Y0 \$ |2 y. _9 r' y! u' o; j5 D
setup-patches
8 C% [4 b+ s3 X make-current one-of intersections
K {. Y1 g7 I# l' Y4 O( h4 n label-current
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set-default-shape turtles "car"6 z: i/ r) d9 s' o: n
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if (num-cars > count roads)% k5 r7 a+ N1 j) Q3 D1 b2 k$ t
[
2 \4 O4 i+ q1 p; [ user-message (word "There are too many cars for the amount of "
: b& s5 b1 m) w: I. k$ n "road. Either increase the amount of roads "; t* L0 E8 [- U8 K
"by increasing the GRID-SIZE-X or "
: v+ T" u) r% U) c "GRID-SIZE-Y sliders, or decrease the "
# \& h; O3 Y% n U2 X: q8 Q3 o* [ "number of cars by lowering the NUMBER slider.\n"
' F7 | n7 [9 b9 S) S9 q8 U3 x "The setup has stopped."), o& W0 [. H/ A' N$ {
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
3 T {8 N' V& C( B8 L# g& X$ ? crt num-cars
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setup-cars
/ C& G2 V9 `7 g set-car-color3 O9 ~) I) \) ~
record-data
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9 i" m9 q+ W6 X ;; give the turtles an initial speed
2 |+ d4 b- d4 @ ask turtles [ set-car-speed ]& D, C4 k0 W B* G
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reset-ticks0 c8 E- c4 I+ ^, U! {
end
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;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet( N9 w3 S! r1 i4 E. p7 @- T/ B
set phase 0
+ N& w. {" v* ?4 u set num-cars-stopped 0
* m( T/ ^4 |: p6 H% a1 A% x set grid-x-inc world-width / grid-size-x
4 ?$ e e |* Y9 A8 S& w1 g9 O set grid-y-inc world-height / grid-size-y' G; Z! a$ h3 x
& \9 a( p) ~; {3 X- g1 o ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary0 s+ [! [" G4 ?; D6 x. j
set acceleration 0.0994 J: o: s# C4 s
end
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* {) U; d. d7 T9 p I8 J& r;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
) z6 z3 c' T7 j' p;; and initialize the traffic lights to one setting% m8 }6 y& L- y3 c& Q
to setup-patches
" _8 l2 j: \' |: d$ }3 N: k ;; initialize the patch-owned variables and color the patches to a base-color
/ |8 ?! t! G& b5 y ask patches5 `6 R6 |+ L" Y& z5 j4 Q c
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set intersection? false
: z% v; |" M% u; g! O set auto? false
' {% M! Z* E+ s9 \0 L6 s set green-light-up? true* ~3 ^2 W( K6 p! [: b
set my-row -1) W# [8 T) t: I$ I' ?: q
set my-column -13 r% ~; T& _9 g5 L2 S
set my-phase -1
8 B9 R7 t3 F9 P+ ] set pcolor brown + 3
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/ L4 F* e( [' P: f ;; initialize the global variables that hold patch agentsets
6 [; ? F V/ c2 H2 z set roads patches with) H' ^7 Y* f. m5 e
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) n' _$ C- @: b. i
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: Q' P1 n" E, O+ i$ m2 s$ F set intersections roads with
9 @) P6 A) M8 ?; \5 O0 R5 f# k [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
! m# ~6 ]9 n* D (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]2 T7 S/ s" A) L2 g O9 i7 |5 N
setup-intersections
. ?" A$ _5 }! D) K# bend
& s" x) y. U4 [. [其中定义道路的句子,如下所示,是什么意思啊?5 F" V; a2 T- T3 `9 {# _
set roads patches with" {3 h6 d, j) a9 J. |, f
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 B- _/ ^ }2 o( h
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]& g8 R0 W( C, r7 N$ `9 q
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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