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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。5 ?( r3 u2 [: a1 x; w+ G7 d8 k
netlogo自带的social science--traffic grid这一例子当中,8 G( A5 J7 K8 D' P- Z
globals" m0 J# c0 D6 j+ o3 H9 E
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grid-x-inc ;; the amount of patches in between two roads in the x direction
9 R7 N H' J$ W2 ] grid-y-inc ;; the amount of patches in between two roads in the y direction! N: }6 d: Q, Z( V8 B ?
acceleration ;; the constant that controls how much a car speeds up or slows down by if
! k7 _0 ?& L/ H ;; it is to accelerate or decelerate
! i' o& b% z& E R( F$ H phase ;; keeps track of the phase* A+ @; v+ J) C' `
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
0 k: g9 u1 v2 c8 o, j5 | current-light ;; the currently selected light1 h3 ^: H3 O; x `$ {- J* t
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;; patch agentsets
0 ^+ z2 K; Q6 N5 N# o- j$ Z intersections ;; agentset containing the patches that are intersections
8 N% ]) ~# e8 D roads ;; agentset containing the patches that are roads
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turtles-own
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: o5 d0 E+ \! `# E speed ;; the speed of the turtle; T6 a0 v) x* `9 I
up-car? ;; true if the turtle moves downwards and false if it moves to the right
" _+ f2 n& ^* D8 o5 n wait-time ;; the amount of time since the last time a turtle has moved1 p! Y# d% ^7 H% h
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e- }% G& k# v a( ^/ epatches-own! ~2 X e |7 e/ r& V6 s
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intersection? ;; true if the patch is at the intersection of two roads
$ y) [- w, K* O- l. x" A1 r green-light-up? ;; true if the green light is above the intersection. otherwise, false.
3 H" i) H1 _) ?+ G1 ]" f) D ;; false for a non-intersection patches.% _1 X" }& O9 q$ D7 ?7 }- J V
my-row ;; the row of the intersection counting from the upper left corner of the
. J0 W9 b5 Z2 C) S. Y6 Z# W ;; world. -1 for non-intersection patches.) ]' }" Q5 [' [. M d
my-column ;; the column of the intersection counting from the upper left corner of the
# M; l; O _3 n) r ;; world. -1 for non-intersection patches.8 x$ D) U0 H: q. G$ r4 r# ^! E
my-phase ;; the phase for the intersection. -1 for non-intersection patches.; ^8 G, m' E: ]
auto? ;; whether or not this intersection will switch automatically.: e. M" _# f% O4 ]: ~
;; false for non-intersection patches.* l! u, \4 X5 H
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;;;;;;;;;;;;;;;;;;;;;;5 g6 _( {; [, i" Q1 N r
;; Setup Procedures ;;4 b! \/ n, Y% a+ L3 F9 j! \8 `1 |
;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.1 m0 X' U) x+ A# A- I( o) A3 E
;; Create num-cars of turtles if there are enough road patches for one turtle to2 G9 p* P0 [3 r* R5 i
;; be created per road patch. Set up the plots.' ^4 b0 l1 i$ @+ O% @
to setup; C r. N5 [' X) f
ca
- y$ t9 A: Q1 a* d6 { setup-globals1 ?. H# r" @2 a: ]3 A* e4 V, p
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;; First we ask the patches to draw themselves and set up a few variables
0 y& ~+ H. Y, ^% o" R6 a/ A) V7 h setup-patches, m% J# f. I# ]0 r; t! s# S3 Q$ o
make-current one-of intersections
7 A9 h. t7 z) r+ I! E) _ label-current
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set-default-shape turtles "car"
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if (num-cars > count roads)2 H! n$ Z( @, q+ B, |' T$ r
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user-message (word "There are too many cars for the amount of "
9 [6 s; {$ v3 o) c9 F$ u: S n "road. Either increase the amount of roads "% s& ?( a' p, P+ E T6 K/ }
"by increasing the GRID-SIZE-X or "
- f2 u; ~; S; U5 G$ v* K6 L "GRID-SIZE-Y sliders, or decrease the "$ G+ z, G* o: {& s5 f+ L) M
"number of cars by lowering the NUMBER slider.\n"
3 ?2 K( _- ^7 z6 z "The setup has stopped.")1 l/ I- I% D3 W1 s; \
stop: c2 R/ T0 c% n( p# X
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color7 J, ^" Z& H w# d
crt num-cars9 ?6 k/ W p8 o" ~ W5 s$ L. A
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setup-cars
! V" ~( @$ G. Z; J4 G$ F set-car-color
7 T) c! B5 N+ [7 B/ m record-data
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7 c8 l$ ^0 c0 o2 v3 a9 R s ;; give the turtles an initial speed5 b+ K' W* g# S6 G
ask turtles [ set-car-speed ]6 e1 H& g X0 k( P' U, [3 B4 ]
a8 i1 A% R; F+ i9 R ^! n reset-ticks
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) m. `$ e# w& _% Z;; Initialize the global variables to appropriate values+ e" E5 K7 M* N4 p- D1 H9 Z
to setup-globals
6 v. b( t/ |( G! E6 L% \8 {; M set current-light nobody ;; just for now, since there are no lights yet
# T* X( [$ L7 M8 F: i0 J9 \0 T set phase 0
* z, p( m' }7 v. q set num-cars-stopped 0
% n* Y. r0 s/ i/ s' Y4 T# o set grid-x-inc world-width / grid-size-x
4 I$ q+ _$ b! Q# B2 d% i& h set grid-y-inc world-height / grid-size-y4 A! t3 f* _) {1 r$ G
- h+ T5 T$ s, p" U ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
+ h& Z& m* c; s set acceleration 0.099
R! i6 D: |2 c2 L* g' j' Lend
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* X* h0 T# w# v! w9 x' i;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
4 i& t+ n6 Y; A$ u;; and initialize the traffic lights to one setting
6 f, X, K% S7 B4 ~; M- yto setup-patches" R5 e/ f# j* m6 f1 U! f
;; initialize the patch-owned variables and color the patches to a base-color
4 O( l. f- a% j' G2 o ask patches3 n* t. d# i; D6 `
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set intersection? false
M" S$ l; q5 k2 ]7 y set auto? false
5 I2 K8 c* @2 S8 @7 ?; O( w- G/ t set green-light-up? true
# U- s# B: O" e0 _/ J+ J# L set my-row -1# x' |' @! `1 B, R( ]
set my-column -15 S1 n# Y$ f, h
set my-phase -1( O# e2 h h R j6 e
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets, u! [* s8 a) w: E' `: m* U0 C
set roads patches with# e. v3 V, t* b9 u. w
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or2 C* t$ d' a6 W" u
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ s: ^7 y& U1 q/ Y
set intersections roads with
+ K, R( _& L7 M* b2 O4 i" m" |; I$ x [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
" _. W8 ?2 o; W4 O4 W3 n F. ~ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]1 ^6 _: @4 L& ^- l2 N+ ]3 U$ x; e6 ^5 U
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ask roads [ set pcolor white ]; t1 k- m3 Y, c+ p0 q1 k7 C* @- t& z
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?# q5 E4 k: Z; O) @1 I" p) g
set roads patches with0 b T Y- _$ [- z7 y/ A. I
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or$ |2 ? H1 B+ x, R
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
T/ @( D. J! n) m- M2 h4 U. f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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