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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。
* J3 [* q9 I n" p" k# Onetlogo自带的social science--traffic grid这一例子当中,
6 m5 Y# U q6 l0 D( Tglobals' e0 K( Q6 @ I5 d7 A" } C
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* ]& i% X8 j7 g grid-x-inc ;; the amount of patches in between two roads in the x direction8 b( [7 X# O/ Y3 N+ m d; b
grid-y-inc ;; the amount of patches in between two roads in the y direction- _% m: E% N8 s0 s
acceleration ;; the constant that controls how much a car speeds up or slows down by if* a6 v( N8 D! n7 |( O; k
;; it is to accelerate or decelerate9 J: k' o0 e$ b6 v! B* f' l
phase ;; keeps track of the phase3 K" R6 _% _5 |9 p7 S
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
* _, I8 C% w' d) O current-light ;; the currently selected light9 C8 K0 \( E' e. _. `
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;; patch agentsets& n- R6 n; H. l$ D- C
intersections ;; agentset containing the patches that are intersections5 @2 m" \: w$ E. C8 u
roads ;; agentset containing the patches that are roads2 w5 w; \8 B- o4 [* U7 }7 H+ m
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N! \0 D0 e- n$ d" U8 S/ _/ J! I6 nturtles-own
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7 E7 w Q7 b7 d4 ^ speed ;; the speed of the turtle3 y/ [9 J5 k# ?& C
up-car? ;; true if the turtle moves downwards and false if it moves to the right
2 A. s) k' s2 G, E" j" Q+ j3 [ wait-time ;; the amount of time since the last time a turtle has moved r+ A/ t- _% ^# v, b# P" ?
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- Y) m& G9 y8 G: q& z' f; spatches-own7 [0 E7 F3 }2 H# p
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* ^: d$ G/ P: c7 G. v5 i intersection? ;; true if the patch is at the intersection of two roads. D4 w0 M8 P! u/ ` C
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
3 r$ C* w! M* l& S2 b @' V: f ;; false for a non-intersection patches./ p# x' n! W, F$ c
my-row ;; the row of the intersection counting from the upper left corner of the' t, J- Q: K( ?+ U& U5 u
;; world. -1 for non-intersection patches.
- t" e5 Y7 t0 C8 p) ] my-column ;; the column of the intersection counting from the upper left corner of the. p# N/ p; _& @7 k
;; world. -1 for non-intersection patches.
2 m* |& O- s* r0 ~5 ~# ` my-phase ;; the phase for the intersection. -1 for non-intersection patches." ?4 k1 g. V8 `- G
auto? ;; whether or not this intersection will switch automatically." j: x2 P) }8 u0 [' W
;; false for non-intersection patches.
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' m$ N: V! n7 I( G0 Q+ F;;;;;;;;;;;;;;;;;;;;;;
3 @# P3 F1 M: w M' o9 Z;; Setup Procedures ;;
! K# ?0 Y. w" Z/ V; E;;;;;;;;;;;;;;;;;;;;;;3 m; n+ F! a `5 {& \. o- z, A
, P _( K6 m: ~& A;; Initialize the display by giving the global and patch variables initial values.
+ ]. X' Y: Y9 N- R;; Create num-cars of turtles if there are enough road patches for one turtle to4 I% ~4 l7 |0 x
;; be created per road patch. Set up the plots.
2 [0 i; W8 v2 ^to setup
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setup-globals2 N j4 C5 g6 F4 P6 q
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;; First we ask the patches to draw themselves and set up a few variables3 P' R% l; {1 l0 n9 _7 x+ j
setup-patches, w" [- n2 \ L6 R- O- |7 N
make-current one-of intersections
' u+ w' x. A6 n4 s4 I& p/ E. R label-current& _' n2 R& T6 e
7 ]8 t+ Q. c. f9 L' k7 A2 X S set-default-shape turtles "car"4 G0 q2 s' N7 z$ i/ {
+ [4 H% P" W& S* Y2 k4 c6 R if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of ") q" w& V. ~2 n% n6 [2 Q7 @
"road. Either increase the amount of roads ": q7 ^* P) \7 M o
"by increasing the GRID-SIZE-X or "% M. q% \& j! O/ A- W! y- ]; t
"GRID-SIZE-Y sliders, or decrease the ". i! Q, M4 U* c2 j" d! X
"number of cars by lowering the NUMBER slider.\n"# T6 f! b7 D; T$ P! w# e& k
"The setup has stopped.")! }0 ~8 \ Y# f' I, a) r
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
: `2 y$ S4 \- a3 F4 L' c crt num-cars( C) u, \- m: d, E+ [ z$ L4 E# `7 b
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: c7 i# ?/ p, a# ~2 m setup-cars& u# O* c8 J+ J' F
set-car-color2 |8 j& a, \( V- ^
record-data
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% p1 c2 V+ I$ I+ {" m, F% s ;; give the turtles an initial speed: a$ M: M# n: m( @+ Z
ask turtles [ set-car-speed ]- F+ E2 K. R: m+ t$ H
1 y' h0 t9 H1 _% z: P% b7 L# p, w reset-ticks) \3 x# M( e. Y. ?9 ]1 e; W$ x
end8 T% e" p, k1 |5 S
" m) S# E! B1 Y+ a;; Initialize the global variables to appropriate values3 \) X C* L; F
to setup-globals
3 P5 w/ F- p3 e: f, h O" r set current-light nobody ;; just for now, since there are no lights yet
, F! u; n5 z/ \% v s- m* s; a set phase 0
7 e( q8 C J0 a" m" u set num-cars-stopped 0
, @- U5 t, I# ? H set grid-x-inc world-width / grid-size-x
7 E3 |! V4 @" @9 y0 M0 C set grid-y-inc world-height / grid-size-y' I& C5 c# E+ G9 A' a9 }; C, x! C
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary2 L, N0 Z! M8 e* e9 o4 d
set acceleration 0.099
9 W. }9 v% [! p& d" x. f# V# send
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,7 U2 L ^2 s7 q! I6 B; \
;; and initialize the traffic lights to one setting
0 m# x) l0 @0 T7 L. d) g8 _5 V! Xto setup-patches
/ W# }. D, z) _" H6 Q% c$ X5 U! I ;; initialize the patch-owned variables and color the patches to a base-color
3 o! _$ q+ k$ |' [, z2 w ask patches2 L+ l# \' P- j
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9 t1 r# H X& d/ T set intersection? false
" ]8 D9 o# r: b$ R" R: N set auto? false
" P" {/ V7 A) ^4 {/ x set green-light-up? true
0 S) j0 `6 O m$ b set my-row -1
* J; G$ s6 y' u/ H5 ^) _) q set my-column -1
9 {& r% t+ g* k) W7 y6 {- ` set my-phase -14 A8 I" {4 ~0 d" o$ R
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets" S3 C3 D3 L3 Y8 ?0 E8 G" l
set roads patches with
* a k5 |9 w- f6 ~+ v% V [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or! F- F+ K, F" W
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]* ~8 u; ^& T% k3 X2 A- E
set intersections roads with5 H: Q( ^) X! z* g% \
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
' \2 F7 W8 ~3 T6 a3 j/ b (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]. U A( |. E) E' F
setup-intersections0 c% K( E: p& @( s0 g- ]
end) h6 ^; u! n' s* p! q% B" d% O% c
其中定义道路的句子,如下所示,是什么意思啊?
/ w9 a6 y T4 N# h. T3 n* P set roads patches with
$ C( [* x5 {8 S3 ^" y8 b [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 L1 S/ Q. O2 J# V (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 K0 ?, b F0 I5 A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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