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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。% l b5 R" o! R _6 ^
netlogo自带的social science--traffic grid这一例子当中,
$ e; F% q$ J8 C6 u3 _0 Bglobals
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0 E1 p4 [3 y1 a4 E" W" K C grid-x-inc ;; the amount of patches in between two roads in the x direction1 e2 N, X \+ h
grid-y-inc ;; the amount of patches in between two roads in the y direction5 K. Y* f# \8 [4 X! j
acceleration ;; the constant that controls how much a car speeds up or slows down by if
4 T& J, Z: ]2 v) Q ;; it is to accelerate or decelerate% y; d/ w5 o- w* ?$ X6 o' [8 F* h
phase ;; keeps track of the phase
( Z0 N7 m) ?" k, X: Z0 o# W5 O U num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure
^8 S6 G! [# `' \ current-light ;; the currently selected light
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;; patch agentsets3 o- d. j8 g# [' G2 Z( |0 K
intersections ;; agentset containing the patches that are intersections
. q% Q" f* G/ q roads ;; agentset containing the patches that are roads3 b; U2 _3 o7 U& ]
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% W* i( _' [1 k6 Aturtles-own& |6 r7 Q: B$ x
[
( X3 G0 c* B& T. i5 ]/ Y0 V( [ speed ;; the speed of the turtle
. R. u; A5 m- a1 i. x) O up-car? ;; true if the turtle moves downwards and false if it moves to the right; E @2 u0 U0 K* D U
wait-time ;; the amount of time since the last time a turtle has moved. v1 I3 E! N% F. a# w
]
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patches-own B0 c+ c7 E, Y
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intersection? ;; true if the patch is at the intersection of two roads& [* e, e/ t0 K$ m
green-light-up? ;; true if the green light is above the intersection. otherwise, false.1 [8 f+ U+ W, E" R4 K
;; false for a non-intersection patches.
. D# |2 R/ W8 W( H5 b my-row ;; the row of the intersection counting from the upper left corner of the
! _0 U C$ l9 h8 X0 b3 Q ;; world. -1 for non-intersection patches.6 s; M7 W- w, B7 k1 |2 d) S
my-column ;; the column of the intersection counting from the upper left corner of the" e( o! h$ ^3 w- y
;; world. -1 for non-intersection patches.1 w4 R% Y% N; o9 L& s9 j! `, _
my-phase ;; the phase for the intersection. -1 for non-intersection patches.7 r0 y, O B) {$ [ E& v7 y
auto? ;; whether or not this intersection will switch automatically.0 Q6 j0 \' L, }! f5 a4 B. i
;; false for non-intersection patches.& l' `" g! L1 c/ _) E: @ L/ f- e
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;;;;;;;;;;;;;;;;;;;;;;
. a6 v2 y7 a( i+ Y1 L" }. B0 \, i;; Setup Procedures ;;
3 ]2 ?3 w' f4 _" S0 \8 ]( J;;;;;;;;;;;;;;;;;;;;;; W: i* w9 t+ ]! p" [
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;; Initialize the display by giving the global and patch variables initial values.
$ z% t6 h7 z# i9 Y2 L;; Create num-cars of turtles if there are enough road patches for one turtle to
! j8 i# `2 j' e1 i1 u7 B;; be created per road patch. Set up the plots.
) z6 p. Q. g sto setup: j2 ?" m3 w" R' |
ca
" H+ f* }, D8 k- k3 ` setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
: t c8 D0 b/ p/ I d+ C- i setup-patches4 B0 ^% V' R T4 i- l& [( }, Z
make-current one-of intersections
% g+ Y" Y( L6 @6 P label-current
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! t1 m) x5 ^8 Y$ E9 m u set-default-shape turtles "car"
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if (num-cars > count roads)) l8 o x/ K* s0 y& W5 [/ X
[
* H9 V/ O0 C- j user-message (word "There are too many cars for the amount of "
( t0 [' e& u' C! { "road. Either increase the amount of roads "$ e8 P0 u+ |5 b3 v9 y" k T
"by increasing the GRID-SIZE-X or "
X9 q5 A. T Q5 S/ W" e# h "GRID-SIZE-Y sliders, or decrease the "; k! O# C' h R& h/ j
"number of cars by lowering the NUMBER slider.\n") r1 M# b- O5 `& F8 R5 l a
"The setup has stopped.")% u5 ?# ^7 A+ N# I# L j
stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
4 [, Z4 u% b, `8 S& q3 C- S' L crt num-cars
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3 |% u8 x1 f! C, f setup-cars
+ F/ b% M1 e4 ^5 X( s0 x7 b set-car-color# t2 Z5 K/ Y; f# P# H* e+ a! T
record-data* d# R% B' T2 q! S3 q
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;; give the turtles an initial speed
( v; [8 V6 z& Z4 V( J( }) u9 k ask turtles [ set-car-speed ]* ]' O( `3 m" F- @- m. k
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reset-ticks
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, D5 f7 Z! y4 O% m h: ^;; Initialize the global variables to appropriate values7 o% B+ E0 } @! U" R
to setup-globals, f; g/ h: X+ m
set current-light nobody ;; just for now, since there are no lights yet/ y" B4 o* ?5 A) c! U
set phase 0
1 Z5 s2 Y+ l1 }$ K" `8 @+ G9 O) s set num-cars-stopped 0
& p! i8 u0 @- X0 ] set grid-x-inc world-width / grid-size-x
4 [2 Y- u% d* v% V: P7 e set grid-y-inc world-height / grid-size-y& N3 x3 G& J3 `; T. w6 g
- K' H5 y% @* g% v ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary( `( O) h/ }" U! p0 ^
set acceleration 0.099
4 ~& q8 v$ i! w) p+ y& @end# b1 L+ J! R; V7 n8 Q% [
0 E) M. J/ p" k+ N;; Make the patches have appropriate colors, set up the roads and intersections agentsets,2 z, a) [, K( S$ w! N4 ?
;; and initialize the traffic lights to one setting9 V* e5 f& k$ N6 S6 L6 j- Z6 p
to setup-patches: y% L2 N, R F9 Z' @" J/ k0 l8 V! z& ~
;; initialize the patch-owned variables and color the patches to a base-color6 P9 I! @$ @: p& O( v
ask patches% \3 o" ~( z+ f$ u/ s U6 f s
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set intersection? false
% y2 j' D6 P6 E set auto? false
4 D8 s- i% ~$ @' n) p7 w set green-light-up? true
% ?" D- T9 @4 K" h9 ^* R+ u2 c' ?& V0 k set my-row -1/ ^# F# Y8 u( \6 ]0 I' L
set my-column -1/ V7 [ f4 U/ r9 n: d2 U, L6 |
set my-phase -1' l# p X3 \9 U0 k
set pcolor brown + 3
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( K/ R0 K0 I! B! \) x! C8 `# P ;; initialize the global variables that hold patch agentsets2 u1 R1 A8 L$ G# E1 C8 r x
set roads patches with
2 K6 c: S/ Y( `* v7 s. a p5 [ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
: t! Q' l+ @" I( V) {6 e (floor((pycor + max-pycor) mod grid-y-inc) = 0)], v: f& l* S% b& B3 B0 T
set intersections roads with j6 S7 G/ I% v! w+ b
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
4 h( i t9 I( w/ r, g8 |- N: x (floor((pycor + max-pycor) mod grid-y-inc) = 0)]' f& i0 P) J; E, ^/ Z5 h
( S6 ^5 @9 _7 {, Z ask roads [ set pcolor white ]1 [* D/ x) ?/ }, m$ I* A; s
setup-intersections X1 r, q. c( _
end
1 y! A6 g1 d. V7 S) i5 }+ B( Y2 u其中定义道路的句子,如下所示,是什么意思啊?5 ?- l5 R5 z ?* n& `
set roads patches with0 d( E. ]! X" ~: V8 \+ |1 p& b
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or9 g1 J. w9 d+ k8 h3 D' T g
(floor((pycor + max-pycor) mod grid-y-inc) = 0)], e1 F2 N6 N2 w6 w! 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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