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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。$ J$ R4 a' G$ y# w$ X
netlogo自带的social science--traffic grid这一例子当中,% W% \2 D" C2 H' m3 a& h
globals8 K/ Z2 }4 f# `1 F! G
[
+ x; j( o/ Q/ p8 \) a O grid-x-inc ;; the amount of patches in between two roads in the x direction; W$ C% m% Z. u
grid-y-inc ;; the amount of patches in between two roads in the y direction1 _0 n8 ` a! ~0 a7 E6 M* e8 w5 x$ c
acceleration ;; the constant that controls how much a car speeds up or slows down by if
4 T% U- a* G# e$ J n ;; it is to accelerate or decelerate
v3 O, `7 S! ]' G( D phase ;; keeps track of the phase1 Z4 T$ c1 k* m( n& w
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure- k( K, W( d3 U/ O# O6 k) X
current-light ;; the currently selected light
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8 Q3 U3 {* ~) I% A ;; patch agentsets1 L; y, @/ v8 ]/ \
intersections ;; agentset containing the patches that are intersections
# a( S' {' u& [: L: ?8 g roads ;; agentset containing the patches that are roads
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turtles-own5 E) a! a! k( }
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! u1 d8 E: N3 z5 s5 k speed ;; the speed of the turtle
& @8 Z8 Q' b" M: J" O# U D" X& y/ V up-car? ;; true if the turtle moves downwards and false if it moves to the right
* Y9 f5 j& v1 X* y# h+ Q wait-time ;; the amount of time since the last time a turtle has moved
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e+ r1 N3 I8 i: V8 Gpatches-own
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9 I: v8 {; l2 ?- I( o$ M/ I intersection? ;; true if the patch is at the intersection of two roads
, O, B, M* ^9 Z( i green-light-up? ;; true if the green light is above the intersection. otherwise, false.
; @( e* [' q9 `; S3 A3 a+ i8 m ;; false for a non-intersection patches.8 a5 f# m! ], G0 b6 ~
my-row ;; the row of the intersection counting from the upper left corner of the
4 U8 n9 Y- }) w3 Q1 E ;; world. -1 for non-intersection patches.
, n" n: w/ D+ P' h: v my-column ;; the column of the intersection counting from the upper left corner of the: n4 u3 I1 }" M) p) L
;; world. -1 for non-intersection patches.
+ V [ Z, U0 z4 W& W my-phase ;; the phase for the intersection. -1 for non-intersection patches.
$ y" R0 O. ~; Z6 b% |7 i9 X2 n auto? ;; whether or not this intersection will switch automatically.
; |/ H5 Y7 v. M! O ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
' ]" F! J! W( v5 x0 `- C;; Setup Procedures ;;
9 y6 h9 K0 H& h; @: O;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.
- W3 O% f1 L3 h* T7 q' `5 D/ q;; Create num-cars of turtles if there are enough road patches for one turtle to
* g, K3 W J* g! h;; be created per road patch. Set up the plots.8 G# O- B: T- l; E! p
to setup
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, R+ S/ J8 D9 W! S! p; u7 i setup-globals) z8 Q2 E4 w0 ^0 W1 f' x
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;; First we ask the patches to draw themselves and set up a few variables( U3 u2 ?5 W, W1 X
setup-patches0 y2 k# }3 `# G1 {) x% d
make-current one-of intersections, ]6 R6 j5 ^7 v* \
label-current
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+ A9 d! h2 o S) ` set-default-shape turtles "car"5 P) j4 |+ Z! r9 x: }% O1 O8 |
1 ?( s2 M1 m8 ? if (num-cars > count roads)8 E0 L* P7 P2 q2 }7 Z" Y0 e. T
[
! F" m7 t4 V! c. m' a% ? user-message (word "There are too many cars for the amount of "
# w! I2 q0 U5 ~% d: H- @ "road. Either increase the amount of roads "
% L1 U% P' q9 ~3 a( G4 _7 ] "by increasing the GRID-SIZE-X or "& g2 O$ J& H* A8 u; S" L& ^6 q
"GRID-SIZE-Y sliders, or decrease the "( C( b9 u2 X" j$ i0 Q/ ]* y6 |5 r) O% p; K
"number of cars by lowering the NUMBER slider.\n"
$ S7 B6 i" N' R0 t "The setup has stopped.")
0 C H, h6 q( Q+ ], Z stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
! Y& z: c, W/ v Q) s9 k1 v crt num-cars9 Z( V; y G7 g2 z7 O+ A( ~! @* P
[
! p- _, a# P% Q8 @2 _ setup-cars
5 e) i0 d9 d; p* ?, g% x4 M set-car-color$ U/ w' z" L) a' p# ?. ^) R3 U
record-data- N8 k# p1 k0 n$ n3 \ X
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;; give the turtles an initial speed6 z1 W4 z: n5 C) R6 t
ask turtles [ set-car-speed ]
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reset-ticks: Q( h2 q/ O6 i/ V) t
end* L" `/ r( X2 ]
' B1 B" i. G0 T1 Y& X;; Initialize the global variables to appropriate values
9 I/ M2 d2 A# Eto setup-globals
/ y8 n1 }, G! ~8 C- i8 X8 B+ L set current-light nobody ;; just for now, since there are no lights yet# p& I `1 [4 |
set phase 0
L# X4 T) i! ~# A2 w set num-cars-stopped 0
& j+ I) k. f! d1 _8 w set grid-x-inc world-width / grid-size-x
' _$ e4 w. i: S- C8 C7 h set grid-y-inc world-height / grid-size-y/ K' ]' `" d2 g7 x* a. G$ |
' H+ z6 `# H2 W. h+ J ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary: K" k7 t0 ?0 B! W& N
set acceleration 0.099, |. U3 x, [0 n$ o. c9 C
end7 x3 w- [7 S( @. y! f' f
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
M, B+ r; I. Q1 }" k;; and initialize the traffic lights to one setting
3 O7 ~+ k! E4 G6 Y% cto setup-patches
. A* `! w. d, I ;; initialize the patch-owned variables and color the patches to a base-color& z. F8 w& U" P; q) l
ask patches
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+ Y# j6 v( b- y. Z% e6 @) d set intersection? false5 @9 \( X, @, M6 d2 E/ Q# Y
set auto? false$ j& R7 X, C! h9 }/ I/ L i4 A
set green-light-up? true
& o3 P) O& l7 Q9 }( q set my-row -1
) z$ g2 w9 a3 l' m set my-column -1
/ l8 v6 |7 r. Y. f( @ set my-phase -1
, ^) s- a, ? Q! Q1 d7 q+ }3 u set pcolor brown + 3& `2 i' B* Z- ^9 N
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2 f% V; W+ [ S8 ` ;; initialize the global variables that hold patch agentsets
8 W4 s( Z8 K5 u+ N9 Y" b set roads patches with' g+ Q4 g/ w5 C5 o
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or3 ]. r, z& r, d, K
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
# b4 ]0 D' U; |$ n* e set intersections roads with
9 R& V! a2 z; W+ {; V+ C5 d, T [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and4 ?/ [2 R2 A) e# @
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]# w9 s3 }( J' Z; C" n1 A
' x% F4 G" C, q3 }: ] ask roads [ set pcolor white ]
( l: ^% U+ k/ M2 _ setup-intersections. y8 @6 e5 P# p w7 ~: ~( H
end* @( v7 k; l7 N9 E! j; Q
其中定义道路的句子,如下所示,是什么意思啊?( J5 K( U1 l7 x0 _
set roads patches with
0 m6 k' ^' t+ O2 \ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: j! g8 K" K# \- J4 x/ T M (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
5 W' c6 y6 o. }4 \0 k4 n d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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