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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。
: J# R& y7 u5 V3 P3 n; |7 O3 y. Qnetlogo自带的social science--traffic grid这一例子当中,$ s8 d6 w# f3 \2 n1 l, c, h
globals
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grid-x-inc ;; the amount of patches in between two roads in the x direction" y5 E# g. d4 |0 p
grid-y-inc ;; the amount of patches in between two roads in the y direction
* s% z. p* ^; d: S acceleration ;; the constant that controls how much a car speeds up or slows down by if$ P) o7 [& k; v. o, s
;; it is to accelerate or decelerate
5 K( u! z9 s- k- b8 ?8 `" I phase ;; keeps track of the phase
3 r9 E+ i8 p2 t I num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
7 H" w0 k0 p# C+ x8 z5 g current-light ;; the currently selected light$ V7 u4 H, s! ^8 X( l( u
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;; patch agentsets
' E# k( N3 I3 S- O, c, I intersections ;; agentset containing the patches that are intersections
9 H& u3 |& j. T# `/ E' Z) u& o2 y roads ;; agentset containing the patches that are roads
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turtles-own3 `8 z( \! v4 w) o7 h) D6 a
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speed ;; the speed of the turtle
& G8 a+ J: S4 J6 f3 s/ ?- K+ [ up-car? ;; true if the turtle moves downwards and false if it moves to the right" B9 x9 ~( u" Q! j/ Z
wait-time ;; the amount of time since the last time a turtle has moved
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, C: G8 }, Y" a; M; Xpatches-own
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% [) f: [( O/ Q intersection? ;; true if the patch is at the intersection of two roads
% j& h; Y5 c! _ green-light-up? ;; true if the green light is above the intersection. otherwise, false.. M% [, y, U/ F
;; false for a non-intersection patches.
1 T$ O* Z* J9 P+ j my-row ;; the row of the intersection counting from the upper left corner of the
3 U- ]/ C( {2 q3 ]; Z4 G6 L8 x+ T ;; world. -1 for non-intersection patches.: G7 f( J8 D' ~3 Q9 j6 [
my-column ;; the column of the intersection counting from the upper left corner of the
1 d- ?3 q% r. N N3 f ;; world. -1 for non-intersection patches.
- V, P. \. b# e; {2 s+ n my-phase ;; the phase for the intersection. -1 for non-intersection patches.
8 B6 U! k# l4 I0 \! ^2 n, _ auto? ;; whether or not this intersection will switch automatically.
% y$ ~8 q- z0 t; H/ d8 F2 u q ;; false for non-intersection patches.
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: q+ c, D3 f5 E8 m) Y8 k) S;;;;;;;;;;;;;;;;;;;;;;
( @. w2 y* _4 ~: k7 K;; Setup Procedures ;;$ F* T1 j9 h5 i z, M, [9 p
;;;;;;;;;;;;;;;;;;;;;;1 u8 f5 Q, a4 a& U' G
$ o" a) v( i/ i9 W;; Initialize the display by giving the global and patch variables initial values.
6 m/ S" ^) g6 v" N8 A;; Create num-cars of turtles if there are enough road patches for one turtle to
3 n4 h! r! ~$ P$ ^* ^, w;; be created per road patch. Set up the plots.* b: i0 I3 T8 k2 f( O% A+ I% _
to setup
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$ v5 @) V$ z* u* v. t setup-globals! ]4 {) b6 v, a9 R" e# ~& @" y
x5 h$ y% y! \* k! c+ O ;; First we ask the patches to draw themselves and set up a few variables
; [3 ?# U; k: J/ a setup-patches j7 y, |0 z' A! K; q: F
make-current one-of intersections
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set-default-shape turtles "car"
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if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "
$ y4 c7 N8 H8 i8 W: T; T: x5 X "road. Either increase the amount of roads "
0 l7 g7 V/ ?" a "by increasing the GRID-SIZE-X or "$ b# B; F5 x6 k# E; d$ K( `
"GRID-SIZE-Y sliders, or decrease the "/ g7 X# v; L' o$ n( [
"number of cars by lowering the NUMBER slider.\n"
& ?+ R) k; h1 [ "The setup has stopped.")
& z) A/ b/ L" ^$ L* w stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color7 S: J% b7 c3 P
crt num-cars
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4 }1 D; T K5 ? setup-cars, O4 }) {) q& h$ w1 J
set-car-color0 x) q+ V. E" Y6 N9 f. f
record-data4 |4 o. K: y9 b/ u& k! l! r2 M) v
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;; give the turtles an initial speed
7 ^5 Z+ H) X+ b+ r ask turtles [ set-car-speed ]0 J6 g/ ^$ }7 ^
3 |7 q% ]1 K1 B8 c0 Q reset-ticks! A; M( |( T1 _: {- x
end5 D8 T8 s7 N; f2 u) z8 b
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;; Initialize the global variables to appropriate values
3 m: M. B4 L9 A) F2 yto setup-globals; n' W. y; {2 ~7 O# h
set current-light nobody ;; just for now, since there are no lights yet
) g) o W, k* l9 B9 v" E4 b! T set phase 0$ |( Q! e3 i$ W1 c0 o3 e# o* ]& S
set num-cars-stopped 0
8 N, h% t- G/ ]/ }0 k set grid-x-inc world-width / grid-size-x
+ g+ }, J6 f3 n6 m6 [# ` set grid-y-inc world-height / grid-size-y
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# q# Q, A5 c/ s* I: }8 h1 O* J ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary, ?+ H# Y" ?$ k+ y8 C
set acceleration 0.099
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; v6 i7 E3 s8 n1 K4 A2 y' e" k;; Make the patches have appropriate colors, set up the roads and intersections agentsets, B' g' g* r) j t- l% _& Q4 p; U D
;; and initialize the traffic lights to one setting6 a) f# q& u V# i* B! T6 I* W- |
to setup-patches2 [2 W7 \5 E. i, k1 X/ |
;; initialize the patch-owned variables and color the patches to a base-color# d# q0 ?! I/ o3 T5 H5 S0 l
ask patches
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set intersection? false
9 n- `; o3 R3 u) I2 U. T+ | set auto? false
# r, m& C/ Y* l0 x2 f' U; a9 X set green-light-up? true
% N! a: x# ^! U7 H+ C1 K set my-row -1
! h6 |1 P2 x4 I/ A set my-column -1; `2 g. J, }+ T+ B# u+ h3 [
set my-phase -1
( h1 e# }1 i; i! |3 X) A/ a4 f set pcolor brown + 34 c" I) D8 }6 i% @
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;; initialize the global variables that hold patch agentsets( F. O x8 x9 ]1 Q; n
set roads patches with
1 s( K4 q4 E" c/ d: ?8 n" P' ~ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
& P$ U6 J7 P7 q" q0 O( d3 F* A3 a (floor((pycor + max-pycor) mod grid-y-inc) = 0)]) D! u. s' @) g+ Z
set intersections roads with
+ V9 O0 f3 t: \- C" Y% `* d1 b [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
; I6 a) M( {% Q1 G" R (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]
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end }! {6 k; I" w5 j$ h+ h* e! y; @
其中定义道路的句子,如下所示,是什么意思啊?) j' ^7 Q8 Y3 V! P( w2 g* U
set roads patches with( L! D. J( o9 w8 W- B* \
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or0 [6 [! E6 ?- e
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. E5 t3 q1 z* m3 c) B: \ K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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