|
|
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。1 i# k* H; B* O8 [4 R3 V& V
netlogo自带的social science--traffic grid这一例子当中,/ K3 @! y- c% z1 C
globals
8 R( u5 ?3 i) i5 N! b[
4 f( l: B8 o! t. d& ?9 U grid-x-inc ;; the amount of patches in between two roads in the x direction |; @. l% W5 g9 p
grid-y-inc ;; the amount of patches in between two roads in the y direction2 B3 w, }* o B
acceleration ;; the constant that controls how much a car speeds up or slows down by if
" E4 _; n& x, W, } ;; it is to accelerate or decelerate! s9 T: [: H' {$ D2 r+ S
phase ;; keeps track of the phase& [1 _; c U3 J5 ]7 K" R
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure, ?* W/ y3 g# s, m8 Z1 l
current-light ;; the currently selected light# W! O3 `+ ?9 u8 w. G0 j
# U) R: m% u3 z1 e G
;; patch agentsets9 G& ]# z" J5 ^
intersections ;; agentset containing the patches that are intersections
9 S% C6 k- d% [; ]. G6 D roads ;; agentset containing the patches that are roads
* F$ E7 c7 F- u& s6 M5 n( O' r]
% Z& X5 N$ z- ?. Y! d, |: z
- Z" C; o8 s: Uturtles-own# o i/ F+ a; l8 d5 z+ r
[# {; O1 v7 y( I0 N" ^# X" P
speed ;; the speed of the turtle
5 G6 w" T4 p- W, a, @: A# j* \0 U% m up-car? ;; true if the turtle moves downwards and false if it moves to the right
2 \$ d) H6 K( c! T/ W- ~ wait-time ;; the amount of time since the last time a turtle has moved
6 t/ v" @- h+ U" z6 M3 V]
$ P9 T6 u9 y" `% }# G2 \5 j% ~) |1 }- o* {* B5 {
patches-own/ @; c! F0 r; ?2 G8 F
[- x+ G7 T$ c9 p4 O u
intersection? ;; true if the patch is at the intersection of two roads
$ W! }/ U6 T/ | green-light-up? ;; true if the green light is above the intersection. otherwise, false.
- m G1 j! o9 | ;; false for a non-intersection patches.4 j! y( B, A% v& t6 t7 [
my-row ;; the row of the intersection counting from the upper left corner of the
* @! e, K/ O: c$ w- R% M6 r ;; world. -1 for non-intersection patches.! X- x# i3 j ]. u9 B
my-column ;; the column of the intersection counting from the upper left corner of the
3 P. Y m. J- F L ;; world. -1 for non-intersection patches.$ j# {5 E0 K5 ?, x7 n4 Y* D/ q* }* v
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
* I# h. J3 G7 h$ s, G+ G auto? ;; whether or not this intersection will switch automatically.
; L1 Q. n0 K$ }2 G1 H& A; b) ?. i ;; false for non-intersection patches.
3 j. Q. ^! _5 K" B; l]! {( u! H6 L& L _$ B0 B# r5 ~3 I$ a
% d, B8 K+ d6 r) N
7 ^) c; u. J, u: W+ w3 P6 P" [, F;;;;;;;;;;;;;;;;;;;;;; @7 m7 O$ F9 k9 g$ r
;; Setup Procedures ;;
; i; S* E) @6 u$ ^ t9 `& l;;;;;;;;;;;;;;;;;;;;;;% _: r# a1 ~' i# f* S/ E
' W" y+ O, j" a8 r, G
;; Initialize the display by giving the global and patch variables initial values.
+ O2 z6 N8 ]6 O. ];; Create num-cars of turtles if there are enough road patches for one turtle to8 g, X' p( P; _2 F
;; be created per road patch. Set up the plots.
1 C9 n! M2 E; Mto setup1 G: x o8 ]" h) [5 p' D
ca
2 t7 Q! }8 e' I3 j1 V+ ~1 | setup-globals) ?! B8 m( j4 k: \4 m6 ^
+ P5 M& D7 `6 {
;; First we ask the patches to draw themselves and set up a few variables
# t; ~8 ]% [# n6 c, |. T! T% W- k2 f setup-patches; T% R7 D+ k/ u
make-current one-of intersections& w" ~, J- _) ?4 ~+ X' K
label-current
2 Z9 \. k) u' k' X, X( K: y0 S* L# \, S) _" b3 B
set-default-shape turtles "car"
+ n( p6 ]. U( d5 ~$ G
0 s7 T% u" `( c! u- c! I& g if (num-cars > count roads)
# W* z6 a; ?) ]9 i+ E/ ^+ S [- G4 c0 a0 T' p# e5 n3 O1 k" i
user-message (word "There are too many cars for the amount of "
8 t( ?' c% }7 P' f I4 f4 E "road. Either increase the amount of roads "* z1 {% g9 I4 X k. u1 [: C
"by increasing the GRID-SIZE-X or "9 ?9 t+ w6 }0 {4 U; ?8 w( S
"GRID-SIZE-Y sliders, or decrease the "
# A9 ?0 S' a' l "number of cars by lowering the NUMBER slider.\n"/ G! n, q0 z9 C; t- L% W
"The setup has stopped.")) {0 b' p+ B2 Y
stop
4 B a! e* \" V ]: r$ U+ f$ e7 g# o1 X: o2 y, z
, W- D! c# F' \7 O$ C( A6 V$ |
;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
5 U( g; F$ m, {8 [2 o crt num-cars
. ~- g# f% s; \" H [! |" _1 O; @$ W& R% v1 h0 Y
setup-cars
1 l; h6 x: [( ^5 d3 N6 y* I1 ~ set-car-color& j$ b8 F7 O0 m( I+ @. M2 i# i
record-data
7 L1 u; Y' F) v) V4 _* f7 V' v ]
4 j$ S0 i% X" B2 b; P2 o4 k" ^0 v2 r
;; give the turtles an initial speed$ X, o4 o0 r; l8 t- C
ask turtles [ set-car-speed ]% j: Z* J2 D. J$ t. O
6 ?6 u. g5 h5 w o" V- R0 h: Z! S7 P0 M reset-ticks+ C( C* s* M/ Z9 h
end- f* U; S' V$ m2 Z+ c! L
& Q- {% e, K! F6 b) |;; Initialize the global variables to appropriate values
3 D' q+ x7 j0 Y; e4 U, bto setup-globals5 E- Q8 \; p1 Y# }' U( M( o
set current-light nobody ;; just for now, since there are no lights yet; M! w0 z7 {+ j/ c7 N
set phase 0* W# u9 ]/ d, o; l. b+ l
set num-cars-stopped 0
( i: [% x* b5 W3 }" E. c5 L/ _ set grid-x-inc world-width / grid-size-x9 L! \; v1 q5 q$ U9 W/ `
set grid-y-inc world-height / grid-size-y
" R9 }4 n& T0 t
~2 }' @! V/ p: w6 V ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary* i% j; ]7 E1 j. D9 W: o/ `
set acceleration 0.099
2 G3 @# m o# `end3 ?' M: C7 T, E5 D7 N
# |3 g/ g8 J0 E4 s Y. `$ V;; Make the patches have appropriate colors, set up the roads and intersections agentsets,9 t, c: l' A" F' Y8 ]. N
;; and initialize the traffic lights to one setting! b0 a2 Y! ~ V8 g) m5 o
to setup-patches/ M g1 q [0 d- D" j* d: J6 o
;; initialize the patch-owned variables and color the patches to a base-color0 c. p8 b2 l& o# }2 q, P
ask patches* Y& D# h+ V7 Z6 a+ ?
[, B/ Y, ?* i7 U. @
set intersection? false4 _/ w( G# D; P9 a6 D; d+ h
set auto? false5 q# C( j$ m' ^ D) J1 m% r
set green-light-up? true5 D. c6 x# _+ X ?* r0 j# e
set my-row -1 H: d/ d" T* P8 a2 d+ v
set my-column -1" z- x, }7 u+ Y: \" Q3 t5 {+ \
set my-phase -1
9 v6 g( t+ ?3 V" J* T set pcolor brown + 3. |* q1 E2 m- `2 s. p5 a# J
]* L8 l7 i; n, G7 z6 I7 D& [# Q! D
; Z' F( b0 [0 ? ;; initialize the global variables that hold patch agentsets* O. G' \) }! q; y
set roads patches with5 @; d0 I3 b9 y6 J" p! z8 Z
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
) f4 D2 D/ J/ x (floor((pycor + max-pycor) mod grid-y-inc) = 0)]6 b- c& |4 a8 V# q& t1 g8 D
set intersections roads with
& W9 }6 s# i6 h- A' X5 A' ?$ O [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and' L2 E; J; |0 d6 z c0 T+ g8 r
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
9 t0 U4 M$ r6 L& r j. W+ D
0 d* A3 w/ I0 q J7 }; @, q6 t$ a ask roads [ set pcolor white ]
) K. I' H) K, T setup-intersections) |2 Y4 I% B3 \% n( L- |% l
end8 i8 U6 Q: r: j7 C. l
其中定义道路的句子,如下所示,是什么意思啊?
$ \$ Z( O& ~5 C0 e& F set roads patches with
( i/ t1 z5 O6 W& [ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
7 G5 K4 p% C7 s* l @# r4 L (floor((pycor + max-pycor) mod grid-y-inc) = 0)]. U- ], f" ^) [# z8 G0 n# ]. @
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? |
|