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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。0 U7 C' k3 U# V, p) v
netlogo自带的social science--traffic grid这一例子当中,
5 C& Z, Z3 e/ ~9 o3 {6 E/ H* Gglobals
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% n/ c j; |1 z: f grid-x-inc ;; the amount of patches in between two roads in the x direction
& P% `) P( A; g( M" i. M+ z grid-y-inc ;; the amount of patches in between two roads in the y direction$ l* C4 N$ U7 s4 b
acceleration ;; the constant that controls how much a car speeds up or slows down by if6 x Q( R) y( Y! F- e& j
;; it is to accelerate or decelerate
1 U7 a8 R& F6 W9 J$ C phase ;; keeps track of the phase
8 p8 c! ~2 w1 Q/ O; j/ f num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure( p @2 i( V5 Z p% f
current-light ;; the currently selected light( P: u. C# Q. f" `- U
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;; patch agentsets" g, e0 m' N B$ J, h! L
intersections ;; agentset containing the patches that are intersections$ O7 A0 K: \5 I9 S' ?- F. J5 X
roads ;; agentset containing the patches that are roads+ P! r2 l/ L# R4 j6 r
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7 v8 E* j) Q$ m3 z7 H7 T8 H6 iturtles-own6 L# l' k7 N% ~1 A- V
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speed ;; the speed of the turtle
- r2 N! J3 N6 G9 V4 S up-car? ;; true if the turtle moves downwards and false if it moves to the right) K6 X8 U V5 M; E. h4 `' A' c$ Y
wait-time ;; the amount of time since the last time a turtle has moved& V% A/ q/ @7 p) [, H
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patches-own* k! j- D: g5 j) I8 ` @( z/ _3 \
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j4 Q" a4 k0 F( {+ ^* d intersection? ;; true if the patch is at the intersection of two roads
: U4 B; o5 p7 _ green-light-up? ;; true if the green light is above the intersection. otherwise, false.; p* N$ z7 ^1 t' @( Y
;; false for a non-intersection patches. e6 ~. |. i2 a2 q# `
my-row ;; the row of the intersection counting from the upper left corner of the! D! B _1 z" y* E2 I! l% C1 W
;; world. -1 for non-intersection patches.
7 u% a5 l( E* ?% g% b% u7 K+ k& D my-column ;; the column of the intersection counting from the upper left corner of the4 _' ^5 t4 M+ W3 Q( `
;; world. -1 for non-intersection patches.* n: T( O i( ~- w
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
9 W1 R' j7 E0 s b, m7 D auto? ;; whether or not this intersection will switch automatically.$ `( U' w! ~- n+ b$ ~
;; false for non-intersection patches.
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' P2 M$ q& M+ y1 Z7 r/ O;;;;;;;;;;;;;;;;;;;;;;
( q4 Q" I" F# h8 Z;; Setup Procedures ;;
% A% ^! [7 F$ u;;;;;;;;;;;;;;;;;;;;;;
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/ b& o3 c9 Y0 z0 b8 Y;; Initialize the display by giving the global and patch variables initial values.
" ~" q. K' _, Z/ E" d;; Create num-cars of turtles if there are enough road patches for one turtle to
3 Q3 D& _4 b* T( D( a;; be created per road patch. Set up the plots.
, |' ]" j9 d0 _8 _to setup7 @3 s V6 M9 @% x/ [" `: d
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables1 k* ]7 I' N4 F i
setup-patches
: u# i+ N- w; k7 v make-current one-of intersections
) q5 z% x7 j* K4 j3 H% } label-current
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( }. q+ J6 e. m3 c3 c6 f0 B set-default-shape turtles "car"
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! z% i0 ]* E1 o9 ]$ ~1 s if (num-cars > count roads)7 i5 S, e8 L- g. o
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user-message (word "There are too many cars for the amount of "% A$ C6 c3 ]! i* R1 @
"road. Either increase the amount of roads "1 D7 c( V" \9 \7 V
"by increasing the GRID-SIZE-X or "8 B* L$ _ H$ L- [
"GRID-SIZE-Y sliders, or decrease the "
3 o* g7 q" C3 b( g T "number of cars by lowering the NUMBER slider.\n"
1 l( \- }0 ~& F( l "The setup has stopped.")
- g/ X' X" R! K9 J3 N7 b: x stop, R# f7 F& I- ^5 X |
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color! y# P8 T) {# m6 N& v1 J% A w4 L
crt num-cars
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% w* U; @* U$ o( S' o N setup-cars4 d, a* r1 x3 n* }' |
set-car-color
/ H r. A# A% j: S( b record-data# l& |# n6 M' w
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;; give the turtles an initial speed
, l$ T9 V% b2 U: { ask turtles [ set-car-speed ]' i/ z+ ~. J5 X( I
' L& F* h |4 h" N1 x7 C reset-ticks7 V' Z6 o+ { G5 b
end7 d9 g3 o u; F7 c
* T$ J6 ?% E/ \! O+ x;; Initialize the global variables to appropriate values
# H2 y3 [, R) V% k3 {' Qto setup-globals
' ^4 F$ w1 s) p8 ` set current-light nobody ;; just for now, since there are no lights yet
% z, J8 |2 b1 x" z0 U: x set phase 0. R! P' I; R! }1 a$ c
set num-cars-stopped 0
1 S H5 Q% C- q% b/ u set grid-x-inc world-width / grid-size-x) ~7 a- Q/ ~4 F3 }4 x3 O: H I. _
set grid-y-inc world-height / grid-size-y; C, ~: a$ X! k- @* y' Y5 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
: R/ } p2 v' ?6 @ set acceleration 0.099( H' y( y+ \1 @4 T4 [5 C0 A
end4 m; q/ F" d$ t1 l* T- H
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
, t6 V! G/ g: o7 w% ~;; and initialize the traffic lights to one setting
* a3 _. [0 v# A% S% |, Nto setup-patches
( w1 Z8 u: [6 t) N ;; initialize the patch-owned variables and color the patches to a base-color! R: v% Q9 y- _( z2 X% V( J
ask patches
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9 v6 {5 \0 ^8 H& l5 q set intersection? false6 I k# D3 ~" j
set auto? false% t+ u6 i- Q% j- a2 u9 H
set green-light-up? true( D& v! k, B0 J# @0 _3 N8 h: U0 l
set my-row -19 z: G, }# U7 U
set my-column -1
( {8 `8 l) {' M/ N; @3 z/ |1 n set my-phase -1
5 q. E1 X) j+ w* T; K: \ set pcolor brown + 31 `6 ?7 ^7 \0 r# b' i: L) |
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;; initialize the global variables that hold patch agentsets
( }- W- U$ Q* O) ]$ l set roads patches with
# B3 Q+ G. b, I; Y p [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or( ~3 X# P! |6 ?$ m7 O% `( s: [
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
2 m1 D" x/ I' R) B- z: G/ t set intersections roads with$ u5 }8 J( Z, {; [3 V: D
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and. w3 D V" h# `$ B$ H
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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& N7 c* S( h2 Z \; i ask roads [ set pcolor white ]7 S) l6 A& T4 H2 x& I2 H
setup-intersections* X# Q q" Q' x1 |" I0 w- C. k5 i
end
' ?+ O. B2 k! J' s8 u+ ^" l7 @# P其中定义道路的句子,如下所示,是什么意思啊?, z: D/ m! _& ?; B1 W0 x9 k! u
set roads patches with" z0 C" l6 j7 g
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
e; h$ A! V; d. t: B; \' q7 X2 @0 y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]- h! u# p3 t% `2 J) y/ M5 q( _) 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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