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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。
( ^- v" g" [& V/ Q3 m$ U$ ~netlogo自带的social science--traffic grid这一例子当中,
) H: M% M+ Q7 n/ y& C" vglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction$ x( x! @. A) z" S! s' k% V
grid-y-inc ;; the amount of patches in between two roads in the y direction: u" q) h) ^1 I
acceleration ;; the constant that controls how much a car speeds up or slows down by if. ?5 O8 K# Z) r, m
;; it is to accelerate or decelerate
9 R# n7 M; q/ m) \ phase ;; keeps track of the phase
$ h# A, b0 Q. P* V5 Z num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure8 {4 m2 r! G% J! ]4 K. |
current-light ;; the currently selected light, M6 @* w5 q/ J& D7 }1 x
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;; patch agentsets: s, Q" N! c/ B9 |: y* w% _
intersections ;; agentset containing the patches that are intersections
! f3 b S# c9 `7 y8 ? roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle0 p# I( [& V' @9 _8 j
up-car? ;; true if the turtle moves downwards and false if it moves to the right+ \! i( G7 s5 E5 \8 J
wait-time ;; the amount of time since the last time a turtle has moved) I r( B4 E0 a+ `
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2 h: E1 ^$ s0 H& u; @3 b+ F% ppatches-own. H2 G0 X6 J) x4 e; M! w
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intersection? ;; true if the patch is at the intersection of two roads
7 M* r) s) f' j* o' j green-light-up? ;; true if the green light is above the intersection. otherwise, false.
, W4 @; Z% D9 X3 J ;; false for a non-intersection patches.
; y8 G& q# }. M2 r9 Q+ L; l my-row ;; the row of the intersection counting from the upper left corner of the
4 \4 n- s7 J [8 \5 p6 g ;; world. -1 for non-intersection patches.4 p+ A, n. ]) o' @5 R1 N
my-column ;; the column of the intersection counting from the upper left corner of the
3 W8 A0 }3 u9 t8 F5 x: M) X ;; world. -1 for non-intersection patches.1 q) q+ d! n+ x" F- G
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
( D4 Z8 L5 B6 y# c( T1 w auto? ;; whether or not this intersection will switch automatically.+ a: S) o( @+ X* {, a8 c
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;5 j/ S% w* P. |! e: _( r* T
;; Setup Procedures ;;
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;; Initialize the display by giving the global and patch variables initial values.
- r3 b- y4 C( |4 K8 C" C) w;; Create num-cars of turtles if there are enough road patches for one turtle to
2 i J2 z8 `- X1 q: ]0 W;; be created per road patch. Set up the plots.- C* d M) X0 N
to setup# {% Q. {2 I9 n" U7 V( [# F/ B8 V
ca
4 O$ L, T4 L1 V+ d* J- p) a setup-globals, o" _. X2 s$ w+ u" L2 L
) o: L8 r! ]8 o/ Z/ E" n' P9 g I8 ~ ;; First we ask the patches to draw themselves and set up a few variables9 i1 Q5 s4 [- R& Y7 e* m
setup-patches" a j* S8 R$ r5 m) B
make-current one-of intersections/ I+ U6 T3 }: i$ I
label-current5 L/ O+ F3 J0 e4 p: P7 A. b
% x3 \, V r: [3 R set-default-shape turtles "car"
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- K2 H# B; E: G4 }- _7 M+ z if (num-cars > count roads)
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) N6 _5 c+ X; M5 ?/ m6 x user-message (word "There are too many cars for the amount of "" H; v' y+ d. L* Q, a
"road. Either increase the amount of roads "$ Q5 w5 N R' ]* M1 b3 I
"by increasing the GRID-SIZE-X or "
: q; D3 d8 ^ o3 W "GRID-SIZE-Y sliders, or decrease the "
1 Q- m( }7 V. b" l( N# Y& Q- P "number of cars by lowering the NUMBER slider.\n"
' ~, I' Z" }; ^; d "The setup has stopped.")
! D# H& s( z" |- {1 K+ C4 j/ l stop& i0 [6 q; w$ ?5 }
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
# v% \' q: Z6 i crt num-cars
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setup-cars
4 w0 @: c2 }: S* c |! Z$ h3 r, e9 ? set-car-color6 \( c7 F+ i9 `6 M* s$ ?2 d( _, i
record-data3 D; @; W }& _9 n" f9 G
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* V7 _) j1 Q* R; H ;; give the turtles an initial speed
& f5 U! `! X% V3 S2 e1 D" q ask turtles [ set-car-speed ]3 E" \/ s2 r$ s. z: y6 z' u
7 e# z) M( Q9 W, x4 j- a5 |0 Z reset-ticks$ {0 Q' ?0 M/ X$ T
end- Y s9 w5 g6 n# Y, {4 k
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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
$ A& ~, W8 ~2 d- @ _/ n6 k3 X. B set phase 0
% j `: e1 K- @1 J' F set num-cars-stopped 0% ]- ~ ^8 n1 n% n8 R% G; y
set grid-x-inc world-width / grid-size-x5 s5 G; ~6 d8 j+ U/ [9 ?
set grid-y-inc world-height / grid-size-y3 x: F: R0 ?; X
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
8 J0 H i3 ~" `3 J set acceleration 0.099
; w/ P s- H/ ~9 nend
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* D+ U6 n& `3 A' _; r+ E/ [$ r;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
# [( J F, j, d9 H1 {8 X4 w) ~8 e. K B;; and initialize the traffic lights to one setting
% t9 `6 p, @4 U6 qto setup-patches
7 {$ }0 b4 X7 p+ f) D/ d; ? ;; initialize the patch-owned variables and color the patches to a base-color5 G+ h% t# I& s+ d: U1 O9 }% c0 i
ask patches* k9 c+ K6 Q: x3 A
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set intersection? false
. D. N' ?+ p( h3 F* B2 O8 q set auto? false
9 B0 ?6 K* n3 A$ i3 q set green-light-up? true
/ F3 h( |' u+ M8 q9 g; _ set my-row -1
! F. ~* T, U/ s* f6 A. p8 y- C set my-column -1" t6 |+ B. P( p* ~8 E
set my-phase -1
2 @7 T+ ?4 D# h9 i- V set pcolor brown + 3
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; T5 R( ?7 \$ B, o: F ;; initialize the global variables that hold patch agentsets
% L* L% A, k1 S% r+ C6 [ set roads patches with
. W3 `" T5 C4 m$ k9 J/ @ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or1 | h1 h4 j \. ?& E' e! P
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
: o5 X& i8 T2 ^! K4 { set intersections roads with, P+ ?+ V4 ~" f
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and4 \0 Q U+ ]2 h# a/ j, B$ _9 }3 d( E
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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" G8 G, z0 U* b7 i) R6 T ask roads [ set pcolor white ]
5 C$ i" u8 ?( i/ E setup-intersections
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其中定义道路的句子,如下所示,是什么意思啊?! [" l. ^7 x* W" C/ R g
set roads patches with
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(floor((pycor + max-pycor) mod grid-y-inc) = 0)]- y9 O$ U+ d1 C/ B
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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