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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。% E1 M' |% u' f. G2 S0 p
netlogo自带的social science--traffic grid这一例子当中,
0 N& _4 X' K. u% r+ n v' gglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction
# r: [1 ^6 b; d grid-y-inc ;; the amount of patches in between two roads in the y direction6 D; }( r* ~/ L' R' H. p( {
acceleration ;; the constant that controls how much a car speeds up or slows down by if2 v, d' T5 p/ k+ F m/ K2 c
;; it is to accelerate or decelerate3 D$ {, ~# y* W8 h0 [# W) ]! C8 V
phase ;; keeps track of the phase
0 j5 `% U1 e$ a8 A8 { ?+ R num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure: I o, _$ m+ G6 M- X. V* o7 t. c
current-light ;; the currently selected light( G2 C' p( Z. H6 {( E
) h' q% Q5 K& `9 M: f ;; patch agentsets; F: F' ]% W+ }* b$ e# O' U& W
intersections ;; agentset containing the patches that are intersections) q2 D: i3 y9 }# X4 X+ Y! B
roads ;; agentset containing the patches that are roads
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8 k" m' f N" r2 [; ~turtles-own3 {& c. D/ F3 h5 ]- K
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speed ;; the speed of the turtle
& L! b; \, z) h up-car? ;; true if the turtle moves downwards and false if it moves to the right
) Q. |5 y0 r4 o: k) A4 X8 H wait-time ;; the amount of time since the last time a turtle has moved
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, c% Y2 t% X ?% u0 _# dpatches-own
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/ t4 g, \0 u# \, z) M* e intersection? ;; true if the patch is at the intersection of two roads3 ~/ [+ R8 m- J) q3 U g
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
9 _( j# G" `6 v1 j ;; false for a non-intersection patches.1 f a. m% ^; m7 |
my-row ;; the row of the intersection counting from the upper left corner of the1 S" I. X8 V: z
;; world. -1 for non-intersection patches. X9 o) S! Q9 j) c
my-column ;; the column of the intersection counting from the upper left corner of the
! V# C4 j7 g5 K e ;; world. -1 for non-intersection patches.
' A2 z- b) Z4 { my-phase ;; the phase for the intersection. -1 for non-intersection patches.
1 O0 x& F% E5 D% y' R9 G2 F auto? ;; whether or not this intersection will switch automatically.
0 D7 {4 h+ {$ P0 V0 M8 O5 L& Y ;; false for non-intersection patches.# _/ j6 U, H$ F8 K# H
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* `1 }6 C4 Y; `' H% l;;;;;;;;;;;;;;;;;;;;;;7 n* w N; G& I- Z
;; Setup Procedures ;;1 R# J+ K Y- @" L: M5 b) `+ s5 a. @) B
;;;;;;;;;;;;;;;;;;;;;;
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/ L7 Y# y: G% Y! v* d;; Initialize the display by giving the global and patch variables initial values.
) b: E* u4 J! m1 |# o/ ?;; Create num-cars of turtles if there are enough road patches for one turtle to' ~ A6 U5 }/ m; t8 m
;; be created per road patch. Set up the plots.7 t$ H- N& S+ y/ U0 e, F
to setup( C4 m: k. X( e6 w$ u4 o$ `# |
ca
8 e3 s9 m9 L: o. N: { setup-globals2 t3 {! c: k* k, Q
/ N% i6 F! `$ V) t5 v0 ?) {4 S ;; First we ask the patches to draw themselves and set up a few variables9 t2 A8 K! j0 @. O/ @7 D
setup-patches6 P( V' v0 v3 r$ G6 X. q
make-current one-of intersections
8 Q& w1 S6 R" K label-current( v8 R [+ ^0 g" a. Y
3 R# B! T, t9 x1 I. c set-default-shape turtles "car"
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3 g ?+ S4 o5 C. H! m8 r if (num-cars > count roads)
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/ W8 f' D6 D7 c( ~3 O user-message (word "There are too many cars for the amount of "
; g6 Q! E/ d) y* N1 M: |1 I1 P "road. Either increase the amount of roads "* H+ H. j0 h5 @5 }/ N0 m
"by increasing the GRID-SIZE-X or ": k/ v% j- [! l, o0 f# g4 s
"GRID-SIZE-Y sliders, or decrease the "3 Q. |& _6 k M9 q. R7 n. Q
"number of cars by lowering the NUMBER slider.\n"0 {7 w- Z9 p. W& c6 ]
"The setup has stopped.")4 q9 h# s5 o8 J3 Q& S( [
stop( E1 O6 K# j, N, X1 n
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
% U( S1 I y2 E( d% T8 I, y crt num-cars
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! K+ v2 C8 \$ e% `$ B setup-cars
7 z5 C; x( l: W3 E. r0 {- w7 o set-car-color
. ]7 @7 v% ]+ F0 C record-data8 i. ~( R; n, ?2 n# m5 e; J- c
]
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;; give the turtles an initial speed }! @% z8 }' p5 r5 Y8 c8 U
ask turtles [ set-car-speed ]
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reset-ticks0 Y5 P1 ~; k2 J. M; d
end
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;; Initialize the global variables to appropriate values
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set current-light nobody ;; just for now, since there are no lights yet: P- }) r6 X$ p4 V$ k L; S0 o. `7 |2 h
set phase 0
" i1 R, v3 t1 i set num-cars-stopped 0
: X7 r+ [- e- r8 _ set grid-x-inc world-width / grid-size-x( i4 D2 P8 \8 o( x; ]- Z* a3 D" K$ C
set grid-y-inc world-height / grid-size-y. ^$ a" F) t6 N7 g* ] P% B
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
& A% u6 {& C4 d/ i, s9 z7 b set acceleration 0.0996 H/ u2 z* @5 v: ^6 S
end
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- g- W: |+ @: ~2 i9 v% ^;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
$ k% d% a/ a* b/ Q;; and initialize the traffic lights to one setting. r: e% ^) `9 T, e7 E' u( J( J2 j; a
to setup-patches
8 z1 |. F$ B# `. ] r9 A ;; initialize the patch-owned variables and color the patches to a base-color; [) a6 a% a9 M' _ ^$ ^
ask patches7 g3 z" A: Q- M
[
# n z3 \- b( f0 I' V0 f# g set intersection? false
4 y5 C. l& E! |% a set auto? false y F1 e# I, P2 r
set green-light-up? true
g* H: x5 T0 E9 a set my-row -1
- M6 b2 a- h. K0 l set my-column -1( W8 \8 r$ ^& O$ T5 ^3 z7 K( w3 ~
set my-phase -1# @8 a2 J6 E4 P C( m) c, l
set pcolor brown + 3
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( |" b( R( M' G1 l) Y! t k ;; initialize the global variables that hold patch agentsets& w4 c; i# o8 s# l
set roads patches with$ T& w+ h) G9 L5 X; r/ F2 Y
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or7 U0 t2 e$ e, o# H' O4 y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]% h3 A0 j9 A3 l5 h4 X
set intersections roads with
7 j: B& m9 w% H) | [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and3 F5 i# t$ t6 d, x/ {4 T" U/ U
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]5 f5 N2 Q2 R/ w3 @/ i# p- u
6 R! N+ { G% N6 W/ f ask roads [ set pcolor white ]( ^5 i" o$ Y, I) q) {
setup-intersections4 I/ y' G9 ^2 e- N
end
( p( s8 M8 J% g, Y其中定义道路的句子,如下所示,是什么意思啊?, j* C. s2 T2 Z
set roads patches with
& u' Y) T# U5 Y/ o [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or b0 ^3 X- e2 s# L
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
# }' n9 Y% r7 x N. W1 t2 @. Y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? |
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