|
|
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) m, |* e: G( Q7 znetlogo自带的social science--traffic grid这一例子当中,
+ R4 i8 b' W; i2 B {$ X( `globals
2 N& t K8 O" n# z[, R( R) D. b+ x, C e
grid-x-inc ;; the amount of patches in between two roads in the x direction
' {! ^; X& \' e grid-y-inc ;; the amount of patches in between two roads in the y direction* K0 D) G: {* ~$ v( O7 `
acceleration ;; the constant that controls how much a car speeds up or slows down by if
* X. s. G$ r3 {& P. J* y ;; it is to accelerate or decelerate; R; A' D3 p' j7 K
phase ;; keeps track of the phase
/ T( y- V+ l8 d% X6 c5 }1 U6 ~ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
# w7 r2 l, \5 p- }9 d current-light ;; the currently selected light
, N# D5 o) t& @
7 I5 j7 a2 h/ {7 k( m6 J& B ;; patch agentsets
5 N0 e. ^- e v8 B( b3 z" L intersections ;; agentset containing the patches that are intersections
# `+ l8 x. o6 H- Q# S) U roads ;; agentset containing the patches that are roads
" Q8 S6 L; |" M- Y' X: Z# {]5 t, X" \: U. J. ]# m* a9 E" P
; Y4 q9 Q0 p2 o0 s5 E& @
turtles-own
# i: i6 j' ?1 W z7 q I8 g[
0 y8 L8 t( E, Q, z5 L speed ;; the speed of the turtle
5 w# r$ k' @# N' j5 c up-car? ;; true if the turtle moves downwards and false if it moves to the right
# U. L6 e& A/ ] wait-time ;; the amount of time since the last time a turtle has moved7 k7 H% K( s, ^7 ^+ H* u
]
6 R& i. ]+ I# N7 ?% M8 n8 s
; L( ~, O, f8 _& V+ \3 h+ ]: y+ Dpatches-own
7 f, u: @' P1 U! K[
/ |, u' h, g6 r3 i1 x/ E2 |& `5 x intersection? ;; true if the patch is at the intersection of two roads
# r$ P6 s+ d1 u) {' V green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! j- |* g8 g( }$ W8 s# H9 Z ;; false for a non-intersection patches.
$ y, ~3 |( ~6 r5 p! l my-row ;; the row of the intersection counting from the upper left corner of the6 n/ T6 @" l1 C' p1 Q
;; world. -1 for non-intersection patches.2 ~$ Y' @1 K: V1 S s; T) L% F
my-column ;; the column of the intersection counting from the upper left corner of the1 o* J' p; w# ?0 K& d. T! A5 y
;; world. -1 for non-intersection patches. A/ C" h) H( e3 w
my-phase ;; the phase for the intersection. -1 for non-intersection patches.1 c5 O: v1 e( y/ ]9 i
auto? ;; whether or not this intersection will switch automatically.4 `) O# v$ G1 S
;; false for non-intersection patches.
# }9 M) b1 f1 T5 T6 z" g]
4 s- u z- j" w: P7 v. X% V: g
4 n0 ]0 J T1 [+ o0 S0 O( K5 E& A/ v& E7 B* b/ a
;;;;;;;;;;;;;;;;;;;;;;
& H' K2 G- Y: ~) ?8 ]" l; d, |;; Setup Procedures ;;# { v- U" v0 u) j! E
;;;;;;;;;;;;;;;;;;;;;;) [& s F2 @1 S/ `5 o
I0 W5 a* c) _$ i;; Initialize the display by giving the global and patch variables initial values.% j$ S. G7 \/ t% D1 ?$ m. D
;; Create num-cars of turtles if there are enough road patches for one turtle to
: }# K7 H* i9 I: p;; be created per road patch. Set up the plots.
. ?% M, N$ }3 ^: \) Fto setup! w8 P5 i8 s8 ~8 p
ca
# a1 n& |' Q+ b4 A( Y" [ setup-globals
5 o# E! E' w. X" I1 P2 f7 \# e, ?9 z7 A
;; First we ask the patches to draw themselves and set up a few variables
3 b Y: }6 u) ]/ g$ x5 Y setup-patches& a8 r' _1 ?' `2 b6 O
make-current one-of intersections7 I3 `4 {# a2 Y0 W$ i" b& y+ K# R# ]
label-current
) I# r3 R3 S4 Y4 S" Y2 o- z6 J, E2 I K S9 y
set-default-shape turtles "car"; \7 V9 H2 l; H K
0 g+ t& |* Y: R, z, ]; k ]( i if (num-cars > count roads)- z7 H }1 W" T3 u
[
; Q8 v( k1 E0 J1 d3 D G5 U user-message (word "There are too many cars for the amount of "6 i6 _3 h* @3 p3 X6 n; ]8 r
"road. Either increase the amount of roads "
/ q4 r, Y; i# ~2 u1 U2 w4 X "by increasing the GRID-SIZE-X or "1 ]) z; y8 e: a0 q* d& A, H' D
"GRID-SIZE-Y sliders, or decrease the "1 {3 D8 q9 y- J
"number of cars by lowering the NUMBER slider.\n"+ o; A1 m7 I; o K. f) g
"The setup has stopped.")) C2 ]# s( U/ {/ g
stop
: ?. H* Z+ B9 M$ Y) D0 N0 Q ]8 U- n$ Z% A6 o
& L# q# U% f7 c
;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
A) U# X/ G' R9 k' b! y' n0 ~ crt num-cars
* Q% M* I* }$ G; U3 V1 J [
& H6 }$ x! ~5 ?1 P3 A6 `" M setup-cars
6 _& o3 x9 Z3 J) }* V set-car-color3 ?: m7 R, d8 p: x/ z" z
record-data
( X+ B2 z% [* M9 x8 L. K0 a ]
2 G. i: Q( ?5 M- T0 z0 v. F9 U+ N+ t: r2 W0 y
;; give the turtles an initial speed
7 I8 X9 ?; i: c) ]9 v ask turtles [ set-car-speed ]
9 _* b1 l( E) C. [+ m9 v- S' w/ R t) Z% b9 j
reset-ticks( U, W/ H0 I0 P" X$ L: B
end
9 @' @5 ~3 n5 v
! q( J" F/ d0 E) n1 [1 R;; Initialize the global variables to appropriate values; h: z% F) l7 W6 W
to setup-globals
5 G' g* t6 k* c# N; I3 d set current-light nobody ;; just for now, since there are no lights yet+ u$ f9 i' k1 O) H9 T5 H% `& x: p
set phase 0
5 F2 j" J$ k8 r+ O" H- I5 B set num-cars-stopped 0
/ N2 m2 b' l% t set grid-x-inc world-width / grid-size-x) D# F0 U4 T( p% d# [& U
set grid-y-inc world-height / grid-size-y3 d) ]1 F" D9 ^( d
- G" w6 F1 n: @1 X4 @) C ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary+ {/ Q2 e2 O+ L" J" e+ @- r
set acceleration 0.099
8 G% c& U6 \ y; Z' i+ y1 mend4 _5 ^9 I. u4 @! u: O
. E# Y4 | z. w) r
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,+ N5 V- j$ G9 {0 _, a" \
;; and initialize the traffic lights to one setting2 f: x% o7 S6 N+ d/ y/ T
to setup-patches" t) k! j) D, W7 P
;; initialize the patch-owned variables and color the patches to a base-color
4 k' u# G* s: Q! u$ e0 S/ r7 Q* w ask patches: Q# L+ k8 ?- o2 \7 X5 ^5 _1 d
[
0 g3 ^) r1 M. n. e4 l, w- ]" i set intersection? false
) s9 _; k, y! |* b: ~$ a. s set auto? false( \/ e$ Q; h7 x* w+ I5 R$ F9 I- z
set green-light-up? true% v% y7 G% G5 L$ y' o- b
set my-row -1
4 z2 L, C; P1 B- [9 }7 H( n3 ?) F set my-column -1
% ?& Y/ F3 {2 {: B1 H set my-phase -1' {$ ]6 W. _3 l! A: |4 b
set pcolor brown + 3
4 D8 w0 M) g2 ~+ t, k ]
, `0 p& ^6 m$ s; u" z
" X% v, o& V8 p+ I: R* f! S& u ;; initialize the global variables that hold patch agentsets
* X' ?6 H$ I2 ?4 l+ W/ B+ V( U4 A set roads patches with
9 l! N2 U0 z( j: K6 k [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) a }' c, K# c! r( M
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
3 E. q9 S" r8 v8 \% S. T1 S set intersections roads with
7 i( q% s" K* z3 I& u7 { [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and7 J- [$ @8 p- h0 | I
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
" R; X8 ]/ i8 l1 Q; j: i& d* d. K; F. P
ask roads [ set pcolor white ]
( J- M; {8 n' i. v7 L setup-intersections
; S* J5 V Y, _* O4 S" lend2 G0 K% [ i8 M; _- ^+ @' @
其中定义道路的句子,如下所示,是什么意思啊? E3 l4 I1 M, n. g' M3 l' u
set roads patches with
* s x/ G. t* N0 `7 A2 x [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or( `/ O* I% F6 A3 |! w
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 A/ M4 Y7 `4 y) `- v+ b# J
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? |
|