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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。3 Q- c8 h% ~ s9 b( k2 N
netlogo自带的social science--traffic grid这一例子当中,, w& E& D1 i. P% A
globals
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9 N& o$ b9 e- F; B: v5 q) } grid-x-inc ;; the amount of patches in between two roads in the x direction; L% L! c& \. n5 g7 S: e
grid-y-inc ;; the amount of patches in between two roads in the y direction, Y5 S' V' j# Q. d2 U6 J
acceleration ;; the constant that controls how much a car speeds up or slows down by if
" `! h9 A/ }. C3 s# O& u ;; it is to accelerate or decelerate) z7 i1 c& D B
phase ;; keeps track of the phase) D: W& v8 g+ n. t- Y3 w% Z
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
/ s* ^: L( h* T8 {, I. P current-light ;; the currently selected light
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;; patch agentsets6 U% _# U) X* h: b; C
intersections ;; agentset containing the patches that are intersections7 d: ?1 N* }6 F. R
roads ;; agentset containing the patches that are roads* j4 `4 g: O- n8 f6 F- ~+ Z6 I
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- F1 I& Q. ]2 |. P4 iturtles-own7 U. E8 ?5 n* ^: K9 S" V5 J
[
5 `4 j( S }6 Y% ?4 _2 n9 O speed ;; the speed of the turtle+ W9 H" W& m u0 i* [
up-car? ;; true if the turtle moves downwards and false if it moves to the right/ s: P/ J5 T: e- i( O `
wait-time ;; the amount of time since the last time a turtle has moved
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; Z( |: c9 C- L/ {% k- o1 Hpatches-own
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$ k3 b; t# q; ]* e, a* Z% r intersection? ;; true if the patch is at the intersection of two roads3 S; R( x' r' E8 v7 I6 t
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
~5 R6 N2 P5 h7 ]7 ^& m; ?7 B ;; false for a non-intersection patches.
, L" ?' g0 N& I' m, \3 S# r my-row ;; the row of the intersection counting from the upper left corner of the O" D1 H4 p! I
;; world. -1 for non-intersection patches.
# q4 q# U5 I y3 q, \5 G my-column ;; the column of the intersection counting from the upper left corner of the
+ c( s+ D" ?* o ~1 c ;; world. -1 for non-intersection patches.
$ _* c4 U0 @: I my-phase ;; the phase for the intersection. -1 for non-intersection patches.4 I* j- x! w4 A' f5 j
auto? ;; whether or not this intersection will switch automatically.
$ U$ J$ F6 {* w ;; false for non-intersection patches.
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& R2 \7 M/ k" n;;;;;;;;;;;;;;;;;;;;;;; ~" v8 ~7 i+ `. F9 O, g
;; Setup Procedures ;;6 s. e, q y# ]1 P; E7 b$ A
;;;;;;;;;;;;;;;;;;;;;;5 H0 D6 x6 e& G) N. \- z
' E: S% Y# ?) S;; Initialize the display by giving the global and patch variables initial values.
1 ^9 k2 y9 j5 e ^* C$ F;; Create num-cars of turtles if there are enough road patches for one turtle to
1 {) Q' q+ i8 J* P;; be created per road patch. Set up the plots.4 u. W4 a: C8 a% T. ]3 S
to setup/ f/ s- d# _' b) D0 y% H- c
ca
! ~; X7 j( A( @3 I3 \ setup-globals
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5 ^' ]8 M7 @4 l" J8 w, w5 y* G' r ;; First we ask the patches to draw themselves and set up a few variables
* ^% \# w* O$ B4 P setup-patches
8 @# h8 Z9 A3 Q0 M: s3 S0 L make-current one-of intersections1 I/ H5 Q, L) N
label-current
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, ^8 Y" A; A* b set-default-shape turtles "car"
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! N3 w2 w2 N4 H: a; ~7 r if (num-cars > count roads)+ w: P' y& L$ ]; m
[
0 A [. X0 @0 ^" C" F% C6 _) q user-message (word "There are too many cars for the amount of ": W7 M9 ?( d) o, ~) X* `/ I, u
"road. Either increase the amount of roads "8 j. R* A. a$ {7 o" v+ A
"by increasing the GRID-SIZE-X or "
9 F8 A Q9 u0 L' S. ^& z9 K. y "GRID-SIZE-Y sliders, or decrease the "
) w- D# n% a$ ]9 T# j$ S) N "number of cars by lowering the NUMBER slider.\n"
! t( [7 I; ?7 T "The setup has stopped.")1 R9 }4 ]$ v, y) l9 P) v' B
stop' P% ^( {+ D2 X; Q: Q5 g8 A3 W; k0 S
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color( ?9 N# m3 H. @* }
crt num-cars3 _* Q h8 {% ]5 Z; C, g+ Z- p
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# f# u$ c5 L" W. F setup-cars" r5 k* ]1 Z. {3 {
set-car-color
; A% ^1 s* q4 ], w record-data
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;; give the turtles an initial speed6 B" A) V0 Z# S3 a6 L8 N" T+ n
ask turtles [ set-car-speed ]: h3 e) g+ q) p
5 V; ?% u/ t- _) U+ c reset-ticks% F- C4 g( Y2 t2 E$ @' _/ X! Q
end( E6 ~- u7 l! k' D: |! v! m
8 t/ q. T, l! ~- Q- ?;; Initialize the global variables to appropriate values# }% e% c) ~# [
to setup-globals9 o* W, H7 `! k
set current-light nobody ;; just for now, since there are no lights yet
/ B' v( @8 `* F7 c4 H% z set phase 03 `# B# n- a# g' y) s
set num-cars-stopped 0+ y/ ^) _ u/ a. M3 q
set grid-x-inc world-width / grid-size-x8 j& ^8 s3 a3 d! I! J
set grid-y-inc world-height / grid-size-y& g3 _; D( v8 ^- d5 n% I7 D1 S6 {0 `
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary# N9 z8 K; P, D; G0 B
set acceleration 0.099* f: F* q0 }8 ]
end
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( h b+ n: }4 x6 f8 ]# i8 W;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
, y, W# G& y; |6 k, V;; and initialize the traffic lights to one setting6 }% @" O1 O# B' e/ V1 Y* M
to setup-patches
, b% t7 u9 R3 ^! [ ;; initialize the patch-owned variables and color the patches to a base-color" a$ H- U- ]5 j4 m3 t. p/ t' h
ask patches0 X2 t9 Q" T1 t: i& C7 \3 O
[
+ [+ S' A: w8 X& u8 J set intersection? false3 M) G! _/ d4 G H9 y! X7 K* j
set auto? false$ ?' x3 s6 A5 T! h' {
set green-light-up? true
3 M. \) R- W) e/ { set my-row -1& G: c3 p. V, R" k
set my-column -1! B6 P: {+ i: _8 D) |" ~
set my-phase -13 }9 C {/ W: u( ?
set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
+ n/ M/ d' b: G! p6 i set roads patches with8 ?3 v3 o) S2 b! y7 j
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or4 r, ^8 }, W, P; D3 U
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
d- Y' V3 ^. @7 v' d set intersections roads with
) d$ S" m \7 c, w* B [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and) |" n4 M% p* d% d& r3 h
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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1 n( O& C3 n' U1 c6 |* l4 M3 \# W8 | ask roads [ set pcolor white ]$ h* b: k4 O( v: f" v
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?, h, U4 B, n8 X0 A l
set roads patches with
8 }/ p. C5 n5 X* }8 t' ? [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or7 @, l7 ]( q- m7 w
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
- f& R4 v: L0 D! D) K8 E8 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? |
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