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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。
F4 Q3 @% I5 Y$ A5 S) q0 P2 @netlogo自带的social science--traffic grid这一例子当中,6 m4 r$ C* O3 s
globals) l6 N3 T; r) E0 Z
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, o( }8 X4 b7 v grid-x-inc ;; the amount of patches in between two roads in the x direction' H2 N+ \7 M; Z3 s- O4 N$ i
grid-y-inc ;; the amount of patches in between two roads in the y direction3 F c0 o! S& A8 x( r+ j
acceleration ;; the constant that controls how much a car speeds up or slows down by if
, n! l3 V8 Z. @8 d* @' z# Q ;; it is to accelerate or decelerate K) _5 p; T& g) M5 H' q
phase ;; keeps track of the phase/ z0 E6 A m1 F8 C7 E! `$ n! P. F
num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
: S, b- C' ~7 Y; X8 z& @ current-light ;; the currently selected light9 B1 g( l- |: {+ @* K
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;; patch agentsets
1 E; Q' l3 {. D4 S# h intersections ;; agentset containing the patches that are intersections8 r; r; {5 o: U T* d5 F3 J
roads ;; agentset containing the patches that are roads
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/ P, M ?& F6 Q% H* ~turtles-own. o& ^3 W* S7 D* A
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& l: a. Q/ [5 [$ G% [ speed ;; the speed of the turtle
/ t4 c' B6 } B7 e. ]: k n J- m up-car? ;; true if the turtle moves downwards and false if it moves to the right
L# _- F2 d" r9 v wait-time ;; the amount of time since the last time a turtle has moved
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patches-own2 Z% J6 K5 Q: V3 C) M1 C" w% Z, p
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intersection? ;; true if the patch is at the intersection of two roads
& O9 B4 v* w$ ]% q green-light-up? ;; true if the green light is above the intersection. otherwise, false.
. @4 V4 `# X% g" A3 U" w" I5 f ;; false for a non-intersection patches.
1 a1 T4 A1 h2 F0 y; G; M my-row ;; the row of the intersection counting from the upper left corner of the
$ W# w' N/ z% B# G1 }( D$ q ;; world. -1 for non-intersection patches.9 _" S4 V; `. _
my-column ;; the column of the intersection counting from the upper left corner of the
( z/ r/ h; O. \8 @8 v x3 _& y, g9 ^ ;; world. -1 for non-intersection patches.
5 u _2 ?8 w* F7 g my-phase ;; the phase for the intersection. -1 for non-intersection patches.
) j5 v6 z7 D& W0 D# X) T auto? ;; whether or not this intersection will switch automatically.: ]0 p6 }' ^1 }4 [" Q9 U
;; false for non-intersection patches.. i9 l% ^3 w. y0 U5 P' h; w. T
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4 d: A% t6 w @% ?$ t) w;;;;;;;;;;;;;;;;;;;;;;
k& N9 I# }' ]! t;; Setup Procedures ;;
7 G. v' R% ~5 W;;;;;;;;;;;;;;;;;;;;;;
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;; Initialize the display by giving the global and patch variables initial values.: k- F% [7 t& M& B( \9 Z; F# v1 b6 ~
;; Create num-cars of turtles if there are enough road patches for one turtle to9 I" q1 Y% u7 s4 D0 @; V9 S
;; be created per road patch. Set up the plots.
6 B4 }; k9 P/ q: a. Vto setup
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
# ]0 X, G5 G4 C7 u$ } setup-patches
# x( r) I$ Z& W9 ]- W make-current one-of intersections7 f: D+ X8 a# y' D! q' S7 F& |
label-current: O; d% {. O: i! Q7 x0 s: N# r- E# _
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set-default-shape turtles "car"
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if (num-cars > count roads): B D& u3 m9 j. q
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: L2 w, r5 F/ q6 g: K& J3 c user-message (word "There are too many cars for the amount of "( F a& h0 ^% }' q6 H
"road. Either increase the amount of roads "+ Y& s. G2 i5 L5 z& |
"by increasing the GRID-SIZE-X or "
& s1 r) r5 P t+ N1 D! s; o: I "GRID-SIZE-Y sliders, or decrease the "5 w t5 e$ N" u; L4 r- q
"number of cars by lowering the NUMBER slider.\n"
% s& L1 u8 B' b' l* _ "The setup has stopped.")
: c" {1 @* \& U. {: _. ] stop
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- z6 T& a4 V1 J9 F; y) z ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
9 V' E; Q1 i; Y o+ t crt num-cars
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8 _0 N; o% Y. i: N1 C setup-cars: g. Z( ^/ p1 H3 u% r: d
set-car-color* ^8 T5 w( X6 n8 U* n4 i+ q3 s/ d
record-data
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;; give the turtles an initial speed4 M5 r, N4 }- x1 c( E4 S1 _% Q
ask turtles [ set-car-speed ]9 ?' \0 y9 D+ v( K+ M
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reset-ticks- Z* a5 V, D' s, C0 t; `
end ^, p( h7 t b* e5 ^2 y
' ?7 \6 @6 C4 q;; Initialize the global variables to appropriate values- {! @1 w" f, V* Z6 ^
to setup-globals- O* k N7 o* T, r6 W
set current-light nobody ;; just for now, since there are no lights yet( t _* ~" m' a$ {& f
set phase 07 F; ~$ _, [2 ?; R0 f: n
set num-cars-stopped 0
8 n! p4 U8 O4 s* K# K: T; D set grid-x-inc world-width / grid-size-x
" ^0 u9 Q3 n/ b, ^ set grid-y-inc world-height / grid-size-y; D% R: ]# b/ N7 f
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
$ B' r; t# I, V! X6 |! l set acceleration 0.099% Z5 Z5 I/ j3 f( I
end5 \- h1 ?5 S- J9 J7 r% r; O
$ C9 x' K' C: `3 ~1 I Y+ g, M;; Make the patches have appropriate colors, set up the roads and intersections agentsets,+ ?, ~, [' P1 S" j4 Z4 }- V8 q
;; and initialize the traffic lights to one setting
/ J5 w8 H8 A; Ito setup-patches! d- S" ~7 E( n; ^ f
;; initialize the patch-owned variables and color the patches to a base-color' S' Y d8 u7 h) @7 {
ask patches
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: j7 j5 N. V r9 b& z1 p8 d! ` set intersection? false9 ~8 c/ u( c. i/ Q& Q( h
set auto? false8 p2 {) N2 t; ?
set green-light-up? true
, s( p7 A/ \% W# o* Q set my-row -1! [! ^0 B/ w6 ?! p+ L! n2 j
set my-column -1
7 `& c5 X: I( X3 s9 G set my-phase -1
( ~+ ^+ ^5 Q8 h. ]" K7 R1 O4 I( t set pcolor brown + 3
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5 o$ z" q0 k8 x. U( r6 [2 R ;; initialize the global variables that hold patch agentsets! Z5 S, ?& E( d! m2 {; e5 s
set roads patches with
* C( c$ ^% m( G, t [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
`& h K. Y. D7 N i (floor((pycor + max-pycor) mod grid-y-inc) = 0)]$ T+ e% @" ]/ p$ f# k" B
set intersections roads with
, h% O) I2 O0 M4 O [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
2 o* k: x- f6 U (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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) I* B) Z, R j9 S5 V5 R8 u ask roads [ set pcolor white ]$ q% e; q: O% J; Z' L! D3 d7 ~: H
setup-intersections/ \& [1 [! | t- `; s* P
end7 {! S! s& {7 x9 R. C' X1 A! f
其中定义道路的句子,如下所示,是什么意思啊?! a9 x7 x8 Z5 F9 W7 [+ G0 @6 `
set roads patches with
2 _) q) b. o; y/ |* t, b [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
1 N1 V6 [% e* i4 T1 C$ @( A (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
8 r* i- o' z* ~8 l" ~) c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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