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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。
7 v1 E% w8 m2 l/ V7 B( p2 {netlogo自带的social science--traffic grid这一例子当中, Y1 C; Y! b) \+ U/ ?1 S1 X' u
globals9 g, y& t; {8 f
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grid-x-inc ;; the amount of patches in between two roads in the x direction7 Y4 h- y; Q" w# U3 J) H0 K
grid-y-inc ;; the amount of patches in between two roads in the y direction g4 [% u; F6 z
acceleration ;; the constant that controls how much a car speeds up or slows down by if
7 k9 G1 @# \6 H; r* v7 [" S ;; it is to accelerate or decelerate0 M' ]2 m$ r) o. p$ D) J" i4 A$ g! c
phase ;; keeps track of the phase
$ S$ e3 w6 W7 u& u- B0 u$ o% Q% T num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
, r q( }3 o: L b9 f3 e2 H9 ~1 E current-light ;; the currently selected light
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: [! [; B2 A7 H& {% \7 P ;; patch agentsets
H8 S J; B7 W) m0 p' c intersections ;; agentset containing the patches that are intersections
. H# R3 L9 k Q! U: \3 \) Q( T1 g2 g- d roads ;; agentset containing the patches that are roads$ Q7 V S/ {! j# s5 B# z j/ a3 n0 G
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0 a H0 ]; K9 {! o2 I3 i$ c. {turtles-own/ v I6 m/ Q( X, s: X! }/ e
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speed ;; the speed of the turtle# P# a! ?3 U9 W' H
up-car? ;; true if the turtle moves downwards and false if it moves to the right9 L! p0 x! u) c% S9 X
wait-time ;; the amount of time since the last time a turtle has moved. _2 i; N2 L k/ ^0 E& R, E5 g& x0 h
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4 Q* y% S! R) a+ V. j& |patches-own
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intersection? ;; true if the patch is at the intersection of two roads+ u; }2 s% O2 q
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
# w9 y1 [* |5 C5 h4 s3 r ;; false for a non-intersection patches.
3 A. v0 a# l( x/ q$ C my-row ;; the row of the intersection counting from the upper left corner of the
/ s' w8 \- q7 Z; I0 `7 v. V ;; world. -1 for non-intersection patches.
+ c" ]8 g- C' p; Z1 x, f4 s4 m" L my-column ;; the column of the intersection counting from the upper left corner of the. U9 C, U3 g' i( K7 ]( H7 D/ ]# D% f
;; world. -1 for non-intersection patches.
% c) p$ [, |0 A5 ^ my-phase ;; the phase for the intersection. -1 for non-intersection patches.1 F/ y& v( z# x, d1 U' K% ~" ~
auto? ;; whether or not this intersection will switch automatically.
9 T9 [/ j- v/ [ ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;$ p9 A* f/ a- _& p }! Q
;; Setup Procedures ;;. D4 J' _8 y9 V/ a1 B- w
;;;;;;;;;;;;;;;;;;;;;;7 W; S7 i( N. u
8 j0 S% O% x$ t/ m( F;; Initialize the display by giving the global and patch variables initial values.% A) }0 u9 n! t# C
;; Create num-cars of turtles if there are enough road patches for one turtle to
4 N* g' }2 A2 J;; be created per road patch. Set up the plots.- g- H9 H& f S
to setup/ Q' _3 y" t- ]/ Q' h' h
ca
2 p6 X; _1 a9 {" c) E- O$ e( n setup-globals5 _8 b( v5 E% b- a7 T7 m
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;; First we ask the patches to draw themselves and set up a few variables6 g: E5 x) J5 V" u
setup-patches& K, @' B6 `. ^ d* O: j$ f
make-current one-of intersections
9 E1 |' T4 H, k+ n8 b label-current
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set-default-shape turtles "car". J5 S* D7 N9 e, J% c
" j; d/ F; a; G& {9 F) V1 p if (num-cars > count roads)
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user-message (word "There are too many cars for the amount of "+ F6 _1 u0 |; s# {- n5 ]
"road. Either increase the amount of roads ". ]$ Z( z) C- l0 g2 j
"by increasing the GRID-SIZE-X or "4 s, h7 W/ [- ^" x8 H
"GRID-SIZE-Y sliders, or decrease the ", Y( c9 g4 ~) f" O; B
"number of cars by lowering the NUMBER slider.\n"
9 U% O Q- f( e% V+ I6 D4 d* k "The setup has stopped.")6 P: _4 E6 @4 ?
stop! I* } a1 a) E& X9 \( |& p
]
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color! W% U) d2 ]+ A$ X' U: E* U" Y
crt num-cars, E* L" Q$ m) j7 P' p8 h$ B
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setup-cars
+ m5 {$ P( O) P. K3 g set-car-color4 }% T1 y2 g7 U) f
record-data
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& J& q5 A" G5 x ;; give the turtles an initial speed2 P6 w: s# x' E
ask turtles [ set-car-speed ]
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reset-ticks o3 O4 B" m* o7 I
end
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: y% L9 e/ f% G7 N# U7 T;; Initialize the global variables to appropriate values' N% p' ?1 q% M$ V
to setup-globals3 x2 }' U$ O7 A/ ^& i
set current-light nobody ;; just for now, since there are no lights yet
$ e+ } {0 R$ r) k" r: { set phase 0 I- c0 O7 S& _" O4 ^( a+ d9 n
set num-cars-stopped 01 `" d+ H. X$ Z3 Y' ^- {1 D
set grid-x-inc world-width / grid-size-x
; a5 @$ Z. i+ r6 ? set grid-y-inc world-height / grid-size-y" s+ ~- T. l; `; A: `8 O6 X; a
1 B9 \7 z1 U: q* j) \3 c ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
3 L' p4 p" E E8 g set acceleration 0.099
) i& n1 Y) n* i/ t& F* fend
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. R8 @7 X } q5 b! a6 K/ q6 ^;; Make the patches have appropriate colors, set up the roads and intersections agentsets,2 h% h2 Y; `9 J: @
;; and initialize the traffic lights to one setting# n' A9 P6 N, f* ]
to setup-patches
4 ^# a( p9 ~6 B, w4 A; ~. j ;; initialize the patch-owned variables and color the patches to a base-color
+ M1 c7 P( o/ r0 t ask patches
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3 c( W* `* W' }) u2 s; J set intersection? false
' h/ Z: o9 F: H6 R8 V. i set auto? false/ [0 ^7 d" O7 R+ L8 b/ U. H
set green-light-up? true& ~) x/ O' I: G, ^
set my-row -1+ ]- U1 I0 [4 O& I; t8 c. L
set my-column -1( @, I, A2 d5 l3 t
set my-phase -18 L; x4 H1 A6 Z* ~
set pcolor brown + 35 h5 F7 z! H9 O- ^. }$ T
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8 J- }% w- m& r0 G ;; initialize the global variables that hold patch agentsets: X' r- r7 p$ r. t4 H- P5 [
set roads patches with
; i: F: R% h- u$ k. {3 w) k [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
2 f2 z# d! i+ U9 @2 q: K (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
( r1 ?. g# \7 v. M" z4 q/ s set intersections roads with9 Z* q: Q! C" n( K
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and0 e C1 R/ J5 F! b' c
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]# \$ \. b' J, T- t2 a! d5 E+ }
0 c6 r- e. P' h1 u, O ask roads [ set pcolor white ]1 m$ |1 g5 P4 ?" n2 F
setup-intersections7 A4 Z7 U0 B5 D6 n( F# g
end8 m, N1 b; @* i7 O a
其中定义道路的句子,如下所示,是什么意思啊?( z% h) g$ Y) _
set roads patches with! [* [" w* u& {, ?$ u+ F, t5 e* |
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
! t2 a4 t. ?8 _( B6 ]4 ?2 V' L (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
1 i2 m# Y1 L' A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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