|
|
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。
5 p4 V# S! {8 V) ~" q+ O+ bnetlogo自带的social science--traffic grid这一例子当中,) w; B- v) d8 x8 s- S5 f; V. K
globals
3 \ e! E8 e0 U# A1 G[
0 B% X. i% @& Z; \8 E& N7 b0 e7 q grid-x-inc ;; the amount of patches in between two roads in the x direction+ |% D- \$ O( {- H7 f
grid-y-inc ;; the amount of patches in between two roads in the y direction1 B. y0 c& G: H+ n
acceleration ;; the constant that controls how much a car speeds up or slows down by if
& e+ `9 ~# Q8 f0 e3 U ;; it is to accelerate or decelerate
+ m) M* s: F8 l phase ;; keeps track of the phase2 [: b& g6 x0 T- L" [ L( V4 \
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
! `/ p% f8 G! I9 T" C# Y% T; v current-light ;; the currently selected light# B) x5 q) v# L/ `4 z
4 F0 Q" Z" B+ _, I2 i2 A
;; patch agentsets
* @/ \" a& L8 U5 t% ]# n intersections ;; agentset containing the patches that are intersections! z9 l0 P& {; Q7 e! q* B, y) E
roads ;; agentset containing the patches that are roads
+ _+ }) S. d% \]& [3 {8 |. ^! @# g: b
U& {! r+ v! j/ e; h. R! y) n- s+ pturtles-own
/ t; {, @6 @, e1 O4 W[
8 o. X; Y. u% v* f& p speed ;; the speed of the turtle
0 `( L. b# E+ o! e! w up-car? ;; true if the turtle moves downwards and false if it moves to the right
! |) T- c i; j2 w5 K$ s1 k/ Y wait-time ;; the amount of time since the last time a turtle has moved$ q/ u/ x) W8 E/ v- t
]
% \' |8 L7 p( [6 O
1 h* c* @ e" R3 V" k, t# Xpatches-own. p$ e* V* Q, H) c( i( ]
[
2 z9 d) S% _8 b- ?% n% P1 d' ` intersection? ;; true if the patch is at the intersection of two roads
2 V. q% O0 o, v a/ u \) D green-light-up? ;; true if the green light is above the intersection. otherwise, false.0 k- G& o m# @& | B
;; false for a non-intersection patches.0 z" k$ ~1 L, g, ` X5 Y s1 |7 g
my-row ;; the row of the intersection counting from the upper left corner of the
/ j: E8 |9 I1 V7 q! C ;; world. -1 for non-intersection patches.- r5 \, N3 Y) P ]+ o* u& w
my-column ;; the column of the intersection counting from the upper left corner of the
, g2 w- k$ k4 z% a& L+ Y) f" k ;; world. -1 for non-intersection patches.
! h3 B: L( ^% T9 e( z. A my-phase ;; the phase for the intersection. -1 for non-intersection patches.9 ~4 |8 ]4 l. H% u7 t2 N
auto? ;; whether or not this intersection will switch automatically.6 n' a4 j5 r. V' y9 J4 @4 @
;; false for non-intersection patches.: E0 @% z/ t4 V- n1 G
]7 W& u5 n! L: \; J0 ?, O
* J# O- n: C/ v6 U( G
0 c! ~, i" W ?
;;;;;;;;;;;;;;;;;;;;;;
+ p5 s& O2 N& i: p+ {- L;; Setup Procedures ;;$ Z/ w; y3 F# R8 k$ R. _! Y
;;;;;;;;;;;;;;;;;;;;;;% Y. f- q! B, f( c! a5 `' l
* |5 ?$ A" V9 v2 K: }: A
;; Initialize the display by giving the global and patch variables initial values.* s$ ^5 l5 q, B# Z; q( X
;; Create num-cars of turtles if there are enough road patches for one turtle to) i/ F& D& w, T- |8 X3 V
;; be created per road patch. Set up the plots.: l1 n9 l" h( i9 K- b, Y" u- L
to setup; y+ I+ ]( G O- W6 \! d/ J
ca6 Y3 I* e4 r: O* M* j# h
setup-globals, i$ w, h; k, m# R5 }
( O6 i- x) U# a y ;; First we ask the patches to draw themselves and set up a few variables+ Z7 C% \# C7 y( O7 g
setup-patches
$ m5 ]0 ~9 H% p$ C2 i make-current one-of intersections/ t8 d. ?0 R- W
label-current7 F K- a( v( |0 b3 U5 b
4 w) w$ o3 a/ |1 R set-default-shape turtles "car"
& S6 q+ `$ y6 t! Z
( p- U! H/ W$ O7 L% Y; u/ n3 i% S if (num-cars > count roads)
. U: A, r+ @" {$ G* S7 r4 r [
$ M: ?. [0 G4 j+ V, Q- Q user-message (word "There are too many cars for the amount of "
( o9 p& c6 P# f& b, M' B3 s "road. Either increase the amount of roads "5 N; ?* W R3 v& v0 [& |" ^
"by increasing the GRID-SIZE-X or "7 p- B z1 g; [! A8 n% D
"GRID-SIZE-Y sliders, or decrease the "9 _+ o4 d* B; j% N, S
"number of cars by lowering the NUMBER slider.\n"2 _" p- G6 j6 q) d9 k/ l
"The setup has stopped.")
7 n' c( s: x+ h/ l stop8 j5 [7 b F8 X. R3 L* e
]
4 S! _) r9 ?2 H; j* o" ]8 }9 Y$ t9 N8 s8 ~
;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
6 k# [! |) I% D! c0 M crt num-cars
; O* R7 M) @' @. a/ T0 U7 u# ` [
9 E% R5 p/ r# X! q2 s) P setup-cars6 n9 E5 @9 A/ N) l, Q
set-car-color
& K% X+ r/ K$ Z, L3 f record-data
4 v$ a; p' A h" ^! w% { ]8 L( ]8 |8 g) |6 C( s
. f5 y9 H6 r9 E2 {5 @6 @ ;; give the turtles an initial speed. ?$ n( @# L4 J, N
ask turtles [ set-car-speed ]# z! c$ d* L. }: `% O5 N1 \# H( T* K. O8 |
; I b# R+ X: ? f reset-ticks1 g0 ~% t% ^+ K& `% l0 G
end
8 X$ E7 p* R- F# v1 f+ z) ], q+ X# A N, S. A: u1 e: O" P0 u. b3 [6 Y. \
;; Initialize the global variables to appropriate values! w3 c2 { }* |, v R- [8 Y
to setup-globals
( i" j- m u1 y2 Y2 }8 F set current-light nobody ;; just for now, since there are no lights yet& s7 Q: z7 o, C8 o
set phase 04 d5 ?* {% Y- l. P% T5 I# ]
set num-cars-stopped 0
* d! s& k' X6 }0 b. a set grid-x-inc world-width / grid-size-x
/ r, b% t) V* g, n4 ` set grid-y-inc world-height / grid-size-y
i+ Y) N- e* l: j7 e
: w. h! V- N2 x ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
3 ]8 V4 j/ b% w; |, J$ X* R" f set acceleration 0.099
# U5 \- m8 x' S4 ^6 [end: X0 g8 ~: w. r' t8 I* {! f$ V
q' j. Z% G, n
;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
) S! u' f" |4 M! g4 @;; and initialize the traffic lights to one setting
8 A$ g: P E; z- F7 ]to setup-patches
5 E8 C% ]- V( Y7 i8 @ ;; initialize the patch-owned variables and color the patches to a base-color
% d0 t+ l* Z7 u) V8 O2 A ask patches
+ Q; \- U/ D- f" f% ` [ c3 k3 F! H1 R+ e
set intersection? false" b4 N6 }3 \: w, o- e
set auto? false( r8 v, \0 o$ ?1 E8 N
set green-light-up? true
5 \# l* S6 h' F8 }7 b1 ^ set my-row -1% ]4 B6 g4 U- ^4 E3 Y" o8 r: `
set my-column -1
3 C" M5 k% F2 d) P \7 Z% X set my-phase -1! s- ~4 M( {7 g! F" n1 B: u
set pcolor brown + 3
. g5 N5 @( Q& w! |! y, l ]$ a' S( h# @- s2 z$ h
9 ?$ J/ Y! B6 u4 a8 n8 ~8 w# c ;; initialize the global variables that hold patch agentsets& U0 L+ j, [$ k
set roads patches with
7 d6 c6 P3 [6 A% B0 Q" S' O [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or! {" K3 C; D7 M/ H" [6 f
(floor((pycor + max-pycor) mod grid-y-inc) = 0)] @ a# S/ G! |
set intersections roads with
7 _1 l5 X* y! F! A: ` n [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and+ l2 ]9 t! u( b0 H1 S n
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]! v) h+ T4 P S# r o7 @
t, r/ m% N& w" j8 G& ^+ S. g4 r
ask roads [ set pcolor white ]/ m; }0 i- R8 r- J' i
setup-intersections
) H& j& M3 V3 K+ I+ H0 [) [2 A, T `, ^ jend- Y* \9 d/ q' d, g" z5 o
其中定义道路的句子,如下所示,是什么意思啊?9 A7 d% c2 m$ I! R
set roads patches with
0 C f& u' t. P5 t7 Q [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or v+ S/ b) x# C- ?: n3 z; |2 y; V, R
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
" R) a# f( x8 k, U0 {- [) u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? |
|