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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。8 ?! H0 ~! ^% l% u) u' F
netlogo自带的social science--traffic grid这一例子当中,
2 {8 `5 I3 A2 g% ~. @2 iglobals
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grid-x-inc ;; the amount of patches in between two roads in the x direction/ V0 {9 w n8 _1 t3 z
grid-y-inc ;; the amount of patches in between two roads in the y direction3 x1 o" ]/ H7 \5 m' ]# M! c
acceleration ;; the constant that controls how much a car speeds up or slows down by if
2 Z5 s$ Q/ `- t( |( i9 b" p8 k ;; it is to accelerate or decelerate: X2 G3 a. V+ i0 A+ @7 a
phase ;; keeps track of the phase
* ]$ u' R6 j' S% C+ C num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
0 o8 S' I. D1 \4 D current-light ;; the currently selected light' H- Z! c3 }" n% I+ {. L
0 g8 G3 k, d3 c" N5 l! W4 ]% t ;; patch agentsets
5 n7 U' u7 y' O/ Z; Q/ R/ z intersections ;; agentset containing the patches that are intersections
+ j( D" U2 H# o/ j9 `) ] roads ;; agentset containing the patches that are roads
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: V1 ^" g" F- b' jturtles-own
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speed ;; the speed of the turtle
) o" {8 s$ P* ^# q B" @( y5 c up-car? ;; true if the turtle moves downwards and false if it moves to the right3 n* ?2 _/ F6 g# g) Z
wait-time ;; the amount of time since the last time a turtle has moved n M! u% A5 S. o: `$ y% {6 l
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[/ T1 f, B+ ?/ q& d; U0 E8 Upatches-own0 f, F4 y0 e- @- c
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intersection? ;; true if the patch is at the intersection of two roads
5 A1 L; o0 N5 C8 Q8 W7 m green-light-up? ;; true if the green light is above the intersection. otherwise, false.1 K. ~. W. u8 C% @% v6 w+ t
;; false for a non-intersection patches.
# E7 I' d) r0 D& e( s* f, E! @ my-row ;; the row of the intersection counting from the upper left corner of the
! t. O Y( j' g ;; world. -1 for non-intersection patches.1 N* y6 v: B8 Y8 C
my-column ;; the column of the intersection counting from the upper left corner of the
" G$ z' A7 t [$ w1 ? ;; world. -1 for non-intersection patches.% l. ]6 {) u& N. ]
my-phase ;; the phase for the intersection. -1 for non-intersection patches.
' R/ ^0 q5 n/ O# ?+ B! @. j auto? ;; whether or not this intersection will switch automatically.6 N! {! x* d9 l5 {
;; false for non-intersection patches.
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) z7 L6 g4 ?8 n0 a0 R( l( H;;;;;;;;;;;;;;;;;;;;;;
( V1 P n7 Z/ k! G4 Y5 m;; Setup Procedures ;;' W: ?& G: `4 o- I- b9 i# i
;;;;;;;;;;;;;;;;;;;;;;
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/ T( L0 z" Q0 V# e0 p9 d) y; L;; Initialize the display by giving the global and patch variables initial values.
; O: f' J. t+ ^5 V' c5 ^;; Create num-cars of turtles if there are enough road patches for one turtle to
6 B' Y: d) u- I6 f+ M;; be created per road patch. Set up the plots.& w# p9 q5 P/ X" _4 _' s% L
to setup+ Q% x4 {+ P, G+ O0 c
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setup-globals
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;; First we ask the patches to draw themselves and set up a few variables( H: d+ ?1 ?5 X
setup-patches/ q" y) Y& |! k( M5 i
make-current one-of intersections# J0 I. F3 T* A+ q& x8 R# Z
label-current
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set-default-shape turtles "car", I. t: V: n! {- Z
+ ?( b) t6 a- \# O% h6 [* O9 J9 ` if (num-cars > count roads)( {( Y. D% J. k0 h. S
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user-message (word "There are too many cars for the amount of "
( l& n& U4 w: y' ^. u. E "road. Either increase the amount of roads "- t5 y+ q% m* \
"by increasing the GRID-SIZE-X or "
9 {% a6 |: T3 G6 L2 h6 e8 Q' A "GRID-SIZE-Y sliders, or decrease the "( H( C+ ]6 Q0 V
"number of cars by lowering the NUMBER slider.\n"0 J) E8 X4 ?+ E3 r* t
"The setup has stopped.")2 Z# I5 K1 Q/ Q5 }
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
& y" [) A, z& M% V7 ~/ {' Z crt num-cars
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# V, \6 I, R A% j s% e3 Q; q setup-cars
5 s3 p! r; ~! ?: [- x set-car-color& D: c: y+ R Y, t# _" f1 L
record-data
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;; give the turtles an initial speed
) p1 L7 t9 s. f. x4 s ask turtles [ set-car-speed ]& Y4 X6 I. i" z- ?
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reset-ticks
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- M) u1 f' k% s+ |& Z;; Initialize the global variables to appropriate values. E( P) r C. B# V% ^! J$ v
to setup-globals
" H+ D, l) I5 r2 ^ set current-light nobody ;; just for now, since there are no lights yet
% t; E8 g- g, g5 r3 e* Y set phase 0
" E, j o9 w2 { set num-cars-stopped 0
% O: P9 Y+ g4 c" N set grid-x-inc world-width / grid-size-x5 }" R, y% A3 q/ _" S1 _- l, k
set grid-y-inc world-height / grid-size-y( B$ Z7 [: v. D
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary6 w) `# y' {& L$ v' v
set acceleration 0.099
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, Y6 j5 h" P5 y+ i9 y;; Make the patches have appropriate colors, set up the roads and intersections agentsets,( l: k% q, z/ {
;; and initialize the traffic lights to one setting
) z# x P& A, Ato setup-patches
4 u% U O/ T0 r1 E ;; initialize the patch-owned variables and color the patches to a base-color' H: L, H. z! A/ K" {
ask patches
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) e* J" R3 V9 Z8 L# Q, C+ S! R/ g# W set intersection? false
0 o O; V1 W0 R$ b. A set auto? false M7 q0 R+ k J% o1 q
set green-light-up? true7 t5 J; k0 e: I% B7 t8 [$ \
set my-row -1
7 S! k3 a5 r% x- C( U" S2 z set my-column -1' n9 V& E4 [( K/ `6 a# C% _
set my-phase -1
5 A/ q' n8 n& t" H6 o. h! ? set pcolor brown + 3& s+ v) J! |$ U. ]' ^: j7 h
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& j1 [ O: N) m7 c4 { ;; initialize the global variables that hold patch agentsets0 U, M4 I, m+ V
set roads patches with
+ u3 r; @+ X; y [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
" P$ `, ?( }) o% E/ o8 v (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
# P" [% i z3 u/ v: ?0 h* D6 n! } set intersections roads with2 a \: W; b; B2 l5 b
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
2 o7 r% @& B e) X% K: m1 z5 @8 Q (floor((pycor + max-pycor) mod grid-y-inc) = 0)]* [) `4 g7 K7 l
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ask roads [ set pcolor white ]2 Y: B! d1 J" O2 n" L9 [1 S. a9 s
setup-intersections: C3 Z7 K8 }' o; k+ ^! {+ \
end! X8 P1 @- Z& ~- ~; G3 x' L" T
其中定义道路的句子,如下所示,是什么意思啊?
, P; {" ^7 O7 `$ a" K- U set roads patches with# H) J) L: G m1 t* Y) P# R
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
/ v% {/ S! `8 J# D, g4 v2 w* j (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
6 P+ C8 c& S! 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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