|
|
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。# k) _# O8 D% F! E
netlogo自带的social science--traffic grid这一例子当中,
* @/ p, k) _5 U, }. a8 x% ^globals
; i3 K. a6 |( a, S0 w* m[
) K6 F' e+ j( t5 r7 x1 z grid-x-inc ;; the amount of patches in between two roads in the x direction1 C' c9 W, r4 E" ^; N
grid-y-inc ;; the amount of patches in between two roads in the y direction9 ?% f& L8 Z, d7 b) m6 c5 }0 E
acceleration ;; the constant that controls how much a car speeds up or slows down by if6 Y M4 y' Z- j2 ~% o7 c
;; it is to accelerate or decelerate
' p1 }6 C9 u" y% E. b! ]! S: i" Q% U phase ;; keeps track of the phase9 J5 J6 l6 v+ z+ J
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
7 \7 t, }: T6 R. s& V% j) F current-light ;; the currently selected light
' e3 Z( L2 G: `: c! l
% h2 b6 V! L4 T( J3 E ;; patch agentsets
6 P$ F% m2 o- O2 s; ?& d# ^% W6 ? intersections ;; agentset containing the patches that are intersections$ d( a' h' r* D8 ^& c$ d2 `6 \
roads ;; agentset containing the patches that are roads) l3 O3 Q6 h* L& @
]/ b; S' ?$ ~% P0 ~ b
- }6 k7 D$ s/ |& Sturtles-own
. N; {/ {" ~" e4 i% i[* ^+ `( m( \1 U2 K: L
speed ;; the speed of the turtle
: b/ W% _2 L! d1 K @- e, y& K/ J7 Z up-car? ;; true if the turtle moves downwards and false if it moves to the right6 d/ r& P8 d/ n8 u7 L
wait-time ;; the amount of time since the last time a turtle has moved
$ I# U. H* T' e4 I0 q]" x2 ~& _) A8 E+ u4 S
& P3 n+ y( H" z3 {9 u/ h4 V+ }( O
patches-own
1 P2 V) g2 Y6 o& l8 b, Y! u[5 p1 V/ ~0 {, `7 |9 s2 c9 O
intersection? ;; true if the patch is at the intersection of two roads
" V, F) c6 o2 K9 P0 X green-light-up? ;; true if the green light is above the intersection. otherwise, false." Q' }( K" Z% S. Q+ Y3 Q
;; false for a non-intersection patches.
' u! D6 E6 x. }0 h- P/ {2 a7 h! T- J! a my-row ;; the row of the intersection counting from the upper left corner of the& p* T( D& [9 R( y Y+ T) l+ n5 N% P
;; world. -1 for non-intersection patches.
8 r: v, r, s, a) x9 m9 I" e* W5 g my-column ;; the column of the intersection counting from the upper left corner of the8 h* J- g. [+ |# `& q b2 I
;; world. -1 for non-intersection patches.
+ S9 A3 Y) a: B my-phase ;; the phase for the intersection. -1 for non-intersection patches.( A3 R5 X1 d0 f1 ` t( F" J5 r
auto? ;; whether or not this intersection will switch automatically.
- x/ M/ B% O- l, K/ Q/ Q5 c ;; false for non-intersection patches.# H& E6 U, N: H
]% c4 }/ l: N$ U ~0 G; y
; o% Q) g% A( N0 f0 F
3 h6 D- p$ A1 Y! P) q+ y H
;;;;;;;;;;;;;;;;;;;;;;
) J3 g8 B( d3 u7 D+ k;; Setup Procedures ;;/ L. I1 h! L0 A, s# D7 m
;;;;;;;;;;;;;;;;;;;;;;
8 o' F8 M# f8 N# [4 G$ F( C# a% l* H' D, {% V
;; Initialize the display by giving the global and patch variables initial values." Z8 V- m$ |7 i) }! j C: C
;; Create num-cars of turtles if there are enough road patches for one turtle to
; J4 l1 t& k8 s, @( g. E" w2 s;; be created per road patch. Set up the plots.
1 Z, ^9 i$ [1 Q+ w4 ato setup* g8 x8 t: m I- i5 K0 c& l0 c) P
ca
" W; l) M: ~$ m! r1 Y setup-globals# \/ `: z! V" M1 i% E) e/ o8 M
7 x. D7 c; I; D% O, G3 \0 {, l" @! R
;; First we ask the patches to draw themselves and set up a few variables
5 z0 z! ^& N0 K) ]; C$ N$ m! J9 A setup-patches
3 b+ C7 Y- H1 m5 n0 |9 A& a make-current one-of intersections0 M' f* ~6 ]( s5 y9 x( h
label-current$ p& s, t" h, D7 d" N6 |
8 e& ^' p( F5 t6 ]5 L set-default-shape turtles "car"
% G- A* ~1 n' n3 P/ }- A) R9 J. h J
if (num-cars > count roads)& ]$ ]! c' w& K& c2 Y
[, o! I* g0 r" [4 q& \% l u1 V
user-message (word "There are too many cars for the amount of "9 E2 X- j: r! _" L$ o* q
"road. Either increase the amount of roads "
$ z& z1 l1 D. u" l: J" c "by increasing the GRID-SIZE-X or "9 Q4 B1 Z6 D& g3 ?# Q% ^$ N' A
"GRID-SIZE-Y sliders, or decrease the "+ }% K9 Z2 F+ a, Y/ k
"number of cars by lowering the NUMBER slider.\n"6 L3 {, b3 {9 j+ ]. h% I
"The setup has stopped.")# P* \: R( e4 l7 J
stop( I+ F8 _ u7 \
]
8 E: v, _/ z3 Y9 I6 c" x; P
. y; \+ }- }! |% q7 y9 I* N8 I# g ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
6 l( a: i% H* e crt num-cars& L6 [8 w1 K( h6 C/ V
[5 H9 [$ a3 e5 a
setup-cars
' |# O0 h3 v* z" }" s set-car-color
9 Y& r9 ~- U! Y5 n1 ?2 D7 T/ W# a record-data( m8 \$ t& B( ^' @( e
]
1 Y+ R* y" Z% f# }& W# v$ M' t- ]$ U, V2 ?6 u& l) }. j/ W4 j- _
;; give the turtles an initial speed; {( R0 j+ i( P8 z' M# u7 e! m5 e
ask turtles [ set-car-speed ]$ Q- [- w; J, r
/ W& J9 W. Y" @- L5 W. o
reset-ticks
: M; D. W* ]" y7 Cend
, C Q4 c9 p0 Q9 N
) ~, @/ x5 _. H3 V& `;; Initialize the global variables to appropriate values9 C$ D* ~" m/ l' L% u- ~
to setup-globals7 P0 ]$ [7 g# E$ A$ w4 C# G1 F) ~
set current-light nobody ;; just for now, since there are no lights yet( u4 M' d6 f" L7 b$ u! C
set phase 06 O- l3 E) w$ T6 z& V
set num-cars-stopped 0
0 l: ^& }! d+ H9 x set grid-x-inc world-width / grid-size-x) r0 d, P4 _$ P. R; X6 Q
set grid-y-inc world-height / grid-size-y! c% N- f9 a$ q& g3 d; _4 k
2 n: b+ p) h) o ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
5 ~: B Y' m# Q7 F set acceleration 0.0991 o$ U* B6 k# M( C4 M9 o
end
$ k& |; O: w) q1 |
8 N: \) V% }9 S+ K0 f/ r4 C;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
2 D7 o% D- L( l$ b. I4 a;; and initialize the traffic lights to one setting$ Z) A3 N% B |4 u) ^) Z. Y
to setup-patches
( q3 s# \& Z1 E. _1 O ;; initialize the patch-owned variables and color the patches to a base-color
; c. T8 G, @0 n( L; \1 I ask patches' C+ ^5 z* e# X5 i* `: Q* F
[
9 o1 {2 q9 c/ [) Y+ P- P set intersection? false. |% F/ c+ ~1 Y' O$ J
set auto? false
5 _8 e8 D0 U! r4 b3 I# |+ o6 v set green-light-up? true) ~9 H2 ?, k* f2 l4 `( ]; E
set my-row -1
* j/ I& ?1 B/ K set my-column -1/ L1 c- I; m: ]* {
set my-phase -1! g4 v6 r/ O2 Y1 r, s6 `
set pcolor brown + 3
! `) f& P+ r$ Q) J" \* G" {8 O' Z ]
/ Z/ s! ^$ L. }. I' ]4 V3 x! R; s# p# M
4 ~; [- ]* j3 t8 Q; y A; K3 |5 h ;; initialize the global variables that hold patch agentsets
/ u5 ?% X x$ v/ {; m/ h4 f4 D set roads patches with
Z) y5 Z8 @- V7 c [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
$ g1 o+ k g, h. o8 u5 ] (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
& M/ _/ z0 ]% v; e set intersections roads with/ D- e( m( Y3 m, Q% h" r
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
4 {" ~% x: u$ I! e& Y (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
8 D0 g2 n3 L- k, Q" @! d1 @& b4 d' I8 ]9 m
ask roads [ set pcolor white ]$ j1 z: F& l* K k
setup-intersections( X" [2 h: f+ K5 R
end- X* u0 Z W* R" }1 Y2 [4 f# j4 |
其中定义道路的句子,如下所示,是什么意思啊?, h- r/ X' H9 R3 `9 E, u' E
set roads patches with
' v) E9 p$ G4 f [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or' a$ c5 s+ C0 o
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
% r4 V5 x2 p0 L: v& e6 L, C/ S, k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? |
|