|
|
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。
- a+ L5 ]6 ?$ Q% |netlogo自带的social science--traffic grid这一例子当中,
/ t0 l/ o, I9 K8 |globals
$ O v; i* p# w9 V& O" D: x' k5 R8 |, k[$ }( e4 \0 Z. w4 O, o# a- a9 ?6 G
grid-x-inc ;; the amount of patches in between two roads in the x direction! z& s$ E0 r$ ?7 N; v' v
grid-y-inc ;; the amount of patches in between two roads in the y direction
1 u/ x4 F+ U- e9 p acceleration ;; the constant that controls how much a car speeds up or slows down by if) @" p8 Z0 ~% \0 J& g
;; it is to accelerate or decelerate; Z) A! Y; j; b5 ?! r- S9 r
phase ;; keeps track of the phase
$ e' P1 S7 m5 I! O2 q1 } num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure9 X% D, }7 Y4 T# Y! n1 V
current-light ;; the currently selected light9 f0 Y; `% h4 V( Y3 N; `
/ _! n( P1 ?6 ^2 S6 m ;; patch agentsets
4 A3 C& L1 F! o, a7 k9 E3 ? intersections ;; agentset containing the patches that are intersections/ Q6 ~: |( E1 p1 ~1 a
roads ;; agentset containing the patches that are roads
$ p( H% t1 b7 J5 S" f& U \2 R6 b]4 M0 c3 P t. B0 s, m% q$ y
3 ?$ g8 e' w5 X) k& R. x
turtles-own
. k$ N @& P3 C5 ~, A& A( {[
4 H$ G$ k+ Y8 `. L4 T speed ;; the speed of the turtle _0 _5 o: m6 Y. j
up-car? ;; true if the turtle moves downwards and false if it moves to the right
4 U+ O1 m$ U1 ~* @: q wait-time ;; the amount of time since the last time a turtle has moved1 s7 \/ z5 L$ J/ ^0 t6 i) u
]
4 x- ^' ]' x+ p6 ~' E, I7 L' q! Z! @6 k3 Z% v# E
patches-own
5 X" s) Z3 G* l% D5 ?[
# y) F# k, [4 i9 _- s intersection? ;; true if the patch is at the intersection of two roads
* M3 D; H4 p7 E* Y- I green-light-up? ;; true if the green light is above the intersection. otherwise, false.
& F- h* X3 f, f8 F+ e% N ;; false for a non-intersection patches.
# N0 |! b$ c5 c my-row ;; the row of the intersection counting from the upper left corner of the
N1 Q( X# A1 Q7 S ;; world. -1 for non-intersection patches.
5 R( p( `; Q$ J$ @ X my-column ;; the column of the intersection counting from the upper left corner of the$ _2 ^: i/ L" Z* T1 D; W' Q3 F% C
;; world. -1 for non-intersection patches.
4 {1 S! j9 Q$ N# S5 x my-phase ;; the phase for the intersection. -1 for non-intersection patches.
: R6 ~. p+ t) u+ g" C( \ auto? ;; whether or not this intersection will switch automatically.
9 m) r& |2 Q$ h% K4 @4 M ;; false for non-intersection patches./ I6 ~ [& o" u9 n) @- u' u, x8 K
]
0 m, ]; ]' F: q$ J7 i, l- R% x: T: D
5 N. f ]% x' n
;;;;;;;;;;;;;;;;;;;;;;2 |, Z2 G. Q$ ?; h) N
;; Setup Procedures ;;6 E3 n; G- C9 |( ^
;;;;;;;;;;;;;;;;;;;;;;" \$ l# f- @/ j4 p$ F, S/ W- p, k
+ P9 R& r! a/ x1 m
;; Initialize the display by giving the global and patch variables initial values./ P; o) k9 z: z H+ t x# ?
;; Create num-cars of turtles if there are enough road patches for one turtle to
6 Q$ A" P* h) Y- J" ?) Q;; be created per road patch. Set up the plots.
" I/ i* q& I! J, kto setup
- X. [' I5 c3 ]% j% x8 k ca; N: b1 y5 Z5 ^) B9 J
setup-globals
- e% {5 o" z, C; o. h5 Y' a8 T- h5 X/ k3 w7 D+ i
;; First we ask the patches to draw themselves and set up a few variables4 L- `4 \0 ?* S+ x/ z* M
setup-patches+ p \4 w" n: x- ]$ ?8 J; m3 t
make-current one-of intersections7 [: q& T3 Q; e4 f u
label-current; M! S3 S8 U3 N5 ] w; Q9 o
d% t* X2 m0 ^( I0 I, ]. M: s set-default-shape turtles "car"
0 F- n6 n* [& D1 @/ o; ~3 E
: h! c- p$ E8 P if (num-cars > count roads)
$ b# L+ j: a& E3 e: O- Y% ]: |* I [. [) a( z5 d( P" x9 x) T
user-message (word "There are too many cars for the amount of " p2 Q8 _8 C1 u! E+ {, ?
"road. Either increase the amount of roads "7 M+ U( H& r- h1 f: ]! i$ B
"by increasing the GRID-SIZE-X or " O' n H, X; j6 \
"GRID-SIZE-Y sliders, or decrease the "
( Z7 S2 S% |! | "number of cars by lowering the NUMBER slider.\n"/ x: Q1 y5 @7 W0 I9 u
"The setup has stopped.")
: y) ]3 E: O6 V# Z. y, y stop7 l" _# P5 a, S" b, v# T9 b
]
2 w: y/ ]( P) W- A8 M9 [; }/ e
8 s9 Y( }- m7 ?- R9 B6 {9 ? ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color7 d. m( b( v! d5 U
crt num-cars
0 Q* M7 |$ D( e' ` [
+ Z$ `/ ~8 ~1 F4 R; ~5 ^+ l setup-cars2 X. H- B5 l9 S9 H- G4 Q i
set-car-color
" v) }/ i& {5 ~) A record-data
3 Z9 i+ k5 U) w5 W1 ^1 d ]' G; [2 {3 L8 M- R( ]3 \; F
7 I5 ` b3 v9 I9 I* f$ }1 k
;; give the turtles an initial speed" Y0 R9 q" S# n3 V0 J
ask turtles [ set-car-speed ]
, H7 s5 \! X- B; q, u( v, f/ P. e, Y4 C' T1 w- k- Y
reset-ticks( ?. H7 ^" d, A, u; ]" @
end' E6 h! [: Z! ]% s7 w; ]
9 J: B/ n# r/ j! W% _;; Initialize the global variables to appropriate values
) V8 v+ ~" y" k7 v+ R8 Oto setup-globals8 {' V2 Q& }' J
set current-light nobody ;; just for now, since there are no lights yet
+ w3 ?# Y: D; n- X/ y8 h set phase 0( Q0 b' ?3 L9 J
set num-cars-stopped 0
; Z7 \& }( A6 ~; ~; W set grid-x-inc world-width / grid-size-x
. f( q( u* A5 b# w$ w( y& l set grid-y-inc world-height / grid-size-y
0 g0 z+ @8 ^, ^7 T) R/ b+ I2 X$ V3 j# f! }8 y: I, I
;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
$ ?/ R7 B8 m$ M" ?, X0 K set acceleration 0.099
$ Y3 j# S$ G$ e2 s- |end" P8 K ~0 D+ }5 p
, V0 n7 U2 ^2 ^" [5 m o9 J# H;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
1 _& r4 l# @& i- [4 N;; and initialize the traffic lights to one setting) ?) T& H, H1 X$ {( K- W
to setup-patches
+ p7 k2 ]* w* I ;; initialize the patch-owned variables and color the patches to a base-color( B! r9 g C3 z* R' R
ask patches
' ?# K/ U6 K3 R0 M4 i, l [
4 V* ]+ {( |! }" i+ l5 f& ~ set intersection? false9 y, ?- D y2 z% I6 h
set auto? false( W: w" j6 ]% y& H" r X
set green-light-up? true
+ V5 l9 z1 E' t/ g: i set my-row -17 W# ^0 K2 p0 M, @ l9 g
set my-column -15 h( _1 J* d, G, U: Q) r$ O
set my-phase -1
* U$ f( ?2 X" _ set pcolor brown + 3 T% p. T. z& I& {- a( i
]
" o1 `$ o! @2 y# m$ v% w7 {! m& A. m4 C
;; initialize the global variables that hold patch agentsets
/ e }4 F9 F$ ?' n' l: J. w set roads patches with4 u3 i) w) |" r2 f% S' n9 Q8 W/ u
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or* Z7 {4 L) N& f( w5 v' T$ |6 S
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 }% |9 G/ I9 [: l4 W; |
set intersections roads with
; Y8 S8 G2 L! N [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
1 c6 a$ S/ u* P" ^ (floor((pycor + max-pycor) mod grid-y-inc) = 0)]; H9 r& T) w: ^3 P9 H: l0 ?
' |) m8 I" |, Z" G5 p$ R ask roads [ set pcolor white ]: B4 D1 p% ~" Y+ s# l7 s7 p
setup-intersections1 H# P. d8 c# U# s5 u @; c6 ?
end
% x" t- ^% Q+ A) Q( _9 {其中定义道路的句子,如下所示,是什么意思啊?& p. m$ U- s9 y2 Z3 l( J
set roads patches with
* N! G: m V4 H/ r( g' g9 ] [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
% B+ l. ?. a f+ E! p (floor((pycor + max-pycor) mod grid-y-inc) = 0)]3 r. {5 a& {+ ~/ C! w$ h$ W1 i% 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? |
|