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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。
- h6 |8 X$ s& E; ^% }netlogo自带的social science--traffic grid这一例子当中,) l4 X& b; _: J7 ~- S$ _+ c) H
globals
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$ E* Q& `- E! |" J: C8 Y# _ grid-x-inc ;; the amount of patches in between two roads in the x direction
1 h, S# `( i& {0 R# s grid-y-inc ;; the amount of patches in between two roads in the y direction
^, b( y: M1 t7 }$ `% v acceleration ;; the constant that controls how much a car speeds up or slows down by if% i& Q' e3 Z) m
;; it is to accelerate or decelerate7 w( o7 C5 @2 a- I o; B
phase ;; keeps track of the phase
: ]' W$ l! }5 A. @ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
3 N0 F) n; B! f2 W* L. k current-light ;; the currently selected light
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, V7 O, n, r- u& `+ h, G1 H ;; patch agentsets3 n; y. x, ]/ r
intersections ;; agentset containing the patches that are intersections% M/ D& T/ T' f! t( a1 _$ \
roads ;; agentset containing the patches that are roads
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turtles-own
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speed ;; the speed of the turtle5 U6 e$ |! d X/ O7 A% N
up-car? ;; true if the turtle moves downwards and false if it moves to the right$ b& q& K, N' D% r, w4 \( f
wait-time ;; the amount of time since the last time a turtle has moved
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0 S* ~# d" m3 G0 q4 s/ _* C5 U8 {patches-own
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$ \0 b$ K+ e p7 K9 g/ O% ~ intersection? ;; true if the patch is at the intersection of two roads1 f1 {( d; y( C
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
8 n# E/ ]. M, |( ?! A ;; false for a non-intersection patches.% F' c8 ~1 C4 m( l, m* T; b! F
my-row ;; the row of the intersection counting from the upper left corner of the: \# x# a$ L! p5 X5 Y8 A9 ~+ P; f' r
;; world. -1 for non-intersection patches.
( j5 c& J$ O+ M" Z) @2 J my-column ;; the column of the intersection counting from the upper left corner of the3 B7 w* S! V0 V7 Q* \
;; world. -1 for non-intersection patches.
' K8 G3 E1 ~! @7 Y. T my-phase ;; the phase for the intersection. -1 for non-intersection patches.$ f/ { {4 J+ _( c5 _5 p/ Z
auto? ;; whether or not this intersection will switch automatically.
4 w9 Y& @+ B% y' t ;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
+ }8 S) ~; o, P4 S* S+ P;; Setup Procedures ;;/ T r( v" r; w) B
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;; Initialize the display by giving the global and patch variables initial values.
' u6 D. u' [- Z3 g% g# B;; Create num-cars of turtles if there are enough road patches for one turtle to
+ U0 j8 A4 f6 K4 @ P: M;; be created per road patch. Set up the plots.( _3 u3 w. D- ?3 \1 k! m' o
to setup- l f6 ^3 D) F9 J* ^
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setup-globals3 v; J) c2 ~/ n+ d
8 I5 J5 n* J, ]. V( A0 x# e* h ;; First we ask the patches to draw themselves and set up a few variables
! V$ q* D) _6 m$ ^% C" P0 P setup-patches
' d# g2 V# q! z1 C make-current one-of intersections
4 y3 q) Q9 K1 U0 l9 b/ Y) Y( \. E label-current
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set-default-shape turtles "car"
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9 S7 @! M# J! g* ?/ R3 S; T! b if (num-cars > count roads)' ~4 W6 u1 Y" C0 j$ H4 |0 q
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user-message (word "There are too many cars for the amount of "
* `2 _: W+ H9 b "road. Either increase the amount of roads "* F/ a( Z- c4 l7 A; ^, K! I$ H
"by increasing the GRID-SIZE-X or "
$ G# o3 S! _0 A! K. `0 U "GRID-SIZE-Y sliders, or decrease the "! Q9 {" n n$ \
"number of cars by lowering the NUMBER slider.\n"
$ e$ l- r+ P& W0 O4 A; Q "The setup has stopped.")
5 H) q4 H6 F: m+ n5 |4 \0 { stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color: F5 I4 q U, ?; x0 t- t
crt num-cars
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setup-cars6 j/ i& ]/ v/ ^( p, r, E
set-car-color
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G$ F6 G: h; ?6 g0 s e" ]$ ^ ;; give the turtles an initial speed
( \0 d( r1 ?" l- W9 E B ask turtles [ set-car-speed ]
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reset-ticks
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4 q; B. _7 b9 q2 Y# m$ G4 V;; Initialize the global variables to appropriate values
+ a9 a9 w: p5 Pto setup-globals( h8 Q6 d. T B+ R8 w6 g
set current-light nobody ;; just for now, since there are no lights yet1 L4 h& x( `& W; s: e5 {7 g
set phase 0: b% O9 M( d+ ?3 Q" a9 O. @8 T
set num-cars-stopped 07 e# e# T7 a) G' T' N
set grid-x-inc world-width / grid-size-x( _# u3 r. }; ]2 ?5 X- z4 a6 [/ h
set grid-y-inc world-height / grid-size-y/ z- I p9 c& A0 R& S
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary5 N- y( w2 l" u% S9 z
set acceleration 0.099
: I: n+ x7 J' t; T! c) F' Yend
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3 \9 r$ N9 @7 \" x J;; Make the patches have appropriate colors, set up the roads and intersections agentsets,- c" u! {& a: u' o/ s
;; and initialize the traffic lights to one setting
. U# w* d% i) ?% }to setup-patches" V4 h P2 v [. Y3 F- m1 R
;; initialize the patch-owned variables and color the patches to a base-color% U, a6 u' H6 t! P! X0 ?
ask patches
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6 s+ R! c( L/ C0 E( N set intersection? false9 M; B! E. y% b3 W% l* m r- P% E
set auto? false
0 b" d# ?) {* H% \' s5 w set green-light-up? true- J. O: @1 c0 r& p
set my-row -1
# v4 z3 [- Q5 W; B5 m) v1 V/ d set my-column -1
5 `2 { e2 ^3 W* Y" a set my-phase -1
# v& W1 p5 \4 _, r- ? set pcolor brown + 3
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;; initialize the global variables that hold patch agentsets
4 f) b+ D8 u1 Y0 W- j set roads patches with
. f& T8 h& J. [5 m) t9 ]3 j9 v! H* o [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or) Q+ V" B6 \# L, B9 y
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
( F, a+ U/ u3 x s; D# C set intersections roads with2 @: f- Y8 [$ w7 H
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and. q- ^+ M' f8 O' d, K- a7 K
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 W7 z% e( z+ V2 X
) ^( @5 a7 y: [. G ask roads [ set pcolor white ]
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其中定义道路的句子,如下所示,是什么意思啊?
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[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
( o4 u+ _9 p0 W+ b; c0 L (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
; m; N* m+ [4 r7 |. v# {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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