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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。
' a- g2 ^8 w# Knetlogo自带的social science--traffic grid这一例子当中,
. \1 e7 M+ ~7 M7 o7 Hglobals! G0 Z: F( `" w1 \
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grid-x-inc ;; the amount of patches in between two roads in the x direction
7 _, `! }7 o0 Z6 k grid-y-inc ;; the amount of patches in between two roads in the y direction3 f6 J/ ^9 r/ @
acceleration ;; the constant that controls how much a car speeds up or slows down by if
3 Z4 j) |0 j1 y) r& ? h ;; it is to accelerate or decelerate+ H. e( G7 t, ~8 }
phase ;; keeps track of the phase
, x& x% ~# c# R1 e# O# B num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure9 S+ i6 R. J% }& ^8 |9 d
current-light ;; the currently selected light& D% W6 H' Z# r3 k/ c9 C
& \* V: {- b }6 u6 ]4 K ;; patch agentsets2 |! E B6 U- U" ^
intersections ;; agentset containing the patches that are intersections* v. t* h, x* M6 g7 P
roads ;; agentset containing the patches that are roads, L# O* x" d/ U) Q
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turtles-own& \8 H2 [) V; L0 b ]
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speed ;; the speed of the turtle
/ x2 {: r; i% u1 [4 `2 e- Q9 d) l4 o C up-car? ;; true if the turtle moves downwards and false if it moves to the right/ f3 w8 h+ H- e$ S4 e
wait-time ;; the amount of time since the last time a turtle has moved( ]1 U/ J6 J+ D% k
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patches-own
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+ p& f, Z+ M+ j1 D, T/ U7 \* C) C intersection? ;; true if the patch is at the intersection of two roads) D$ l8 M* K( r7 q7 w" N9 F3 a
green-light-up? ;; true if the green light is above the intersection. otherwise, false.7 R6 u# b+ P( W- Y: \
;; false for a non-intersection patches.
8 u# W" [7 m4 v: G0 M$ Y" o my-row ;; the row of the intersection counting from the upper left corner of the
8 D* j' x& X$ z8 U% P6 ]0 f5 G ;; world. -1 for non-intersection patches.7 ? ~9 T: [8 l# e
my-column ;; the column of the intersection counting from the upper left corner of the
6 @! G& p' W8 S5 C! q# s* x2 ] ;; world. -1 for non-intersection patches.
: L& ]8 ?7 h1 q( F' Z my-phase ;; the phase for the intersection. -1 for non-intersection patches.4 s4 m' y- V9 a
auto? ;; whether or not this intersection will switch automatically.2 ~5 n3 s6 E7 x" ]: a3 v3 h
;; false for non-intersection patches.7 u0 L% ^+ L% e' j X+ L
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;;;;;;;;;;;;;;;;;;;;;;/ c5 C( @5 n1 [
;; Setup Procedures ;;
% `/ p0 \4 G- q2 L) E, @* c;;;;;;;;;;;;;;;;;;;;;;
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0 H. [* N" i- w1 Y, l4 E;; Initialize the display by giving the global and patch variables initial values.9 O4 }5 l; n( O7 p/ y
;; Create num-cars of turtles if there are enough road patches for one turtle to
" ~0 l/ C( }: x. J3 N;; be created per road patch. Set up the plots.* P% ~5 g5 Y/ ?: \( _9 d
to setup9 N2 s; J5 s/ X
ca0 l8 f+ x' Y( Z+ w4 E# m! C) X
setup-globals7 f7 m) [% h9 m5 O! `" O/ E
5 p! j+ Y, X! L. v: r0 b ;; First we ask the patches to draw themselves and set up a few variables' a9 t( Y0 J8 C$ ]
setup-patches x0 l3 ~2 q0 s& G
make-current one-of intersections7 C5 h7 F) G6 R: i2 H
label-current5 k" D8 M- [! t. B% r
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set-default-shape turtles "car"" I. C2 R% m2 b) w" M
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if (num-cars > count roads)* }6 t g6 w/ V0 ~
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user-message (word "There are too many cars for the amount of "
4 [- |4 ?" \# Z "road. Either increase the amount of roads "
* }! U' |+ y3 G; z4 x+ p, w "by increasing the GRID-SIZE-X or "; n, m2 V0 J6 K! E
"GRID-SIZE-Y sliders, or decrease the "
# l: @5 {8 ]% U% K8 Q6 H6 t* C+ u "number of cars by lowering the NUMBER slider.\n"
7 o9 |& M3 Z) O4 j "The setup has stopped."). j* T1 G5 u, N% A5 ~
stop
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' A- v& b7 ]7 p' {3 u- j; x1 W6 E ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color' N% Q& D5 C0 c! p" Y1 Q3 R2 q
crt num-cars
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setup-cars( i: L" _- _: x$ ^
set-car-color- \8 Y3 e: k6 D0 N- T7 f, t1 w
record-data
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;; give the turtles an initial speed n2 k- t9 r! Z9 R/ H9 L2 ^9 Q+ V: t
ask turtles [ set-car-speed ]+ {, e. p$ f/ ?9 V1 O
0 ~" x8 u2 d1 Q5 P4 _3 w8 ? reset-ticks, H; v6 q/ ^- b v
end# y5 D: h0 ]& J0 t% b6 ], [4 w
, g/ Q6 T2 u/ z;; Initialize the global variables to appropriate values; i% @$ A& E' V2 h
to setup-globals4 j& G3 y, B1 q0 J6 `. C5 u' J' b
set current-light nobody ;; just for now, since there are no lights yet
2 f2 `+ `( W& t* s set phase 0
* U* G' y7 z2 I; N# [6 Z( T& p1 C* j set num-cars-stopped 0( B: R/ H" k0 _5 F* q# N; y- u
set grid-x-inc world-width / grid-size-x. K0 J e5 Q5 n( @! N! Y% D, U
set grid-y-inc world-height / grid-size-y+ z& u/ H0 z( T
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;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
; T. }6 Z; ^# J! a7 B# H set acceleration 0.0992 k+ e3 v( ]3 f8 F4 K. c
end
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;; Make the patches have appropriate colors, set up the roads and intersections agentsets,! B& a- |' G0 O6 x$ r; r5 h
;; and initialize the traffic lights to one setting
( m3 @7 O9 A" C l9 w5 ?to setup-patches
" @7 X8 C+ s4 X; W. | ;; initialize the patch-owned variables and color the patches to a base-color# K& x `* b7 v3 w9 V6 f
ask patches! R/ {6 M4 G2 T. b' H5 L5 X
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" v; R% F7 C o! _! s* ]0 c set intersection? false: X# T. u' {9 X
set auto? false
# K8 Z: Z4 B, g+ X+ q7 [ set green-light-up? true$ ]& F1 {) ?8 P
set my-row -1! e$ ^1 m L7 B5 V; {
set my-column -1! w4 }, y( `4 P. ]3 {
set my-phase -1
0 p; t6 a' j+ d+ E/ D set pcolor brown + 3" M8 y, F9 Y* A( G' ?/ w' [
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& r% p0 P. ~4 {2 U0 c ;; initialize the global variables that hold patch agentsets
/ h+ a! Q3 x: l& f, Q F! p set roads patches with' g2 \2 O* G/ y9 {- w- e/ X
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" _9 r" Y5 l/ I. B( s
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
. \: G4 `; ^* O1 G, y- V set intersections roads with
r8 L% ]" F( n+ |$ h [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
+ m+ D: i+ l( g* I3 O" l (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
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ask roads [ set pcolor white ]2 p3 U$ z# }3 F- m( E8 r7 @
setup-intersections
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4 M- s( b6 [/ m% y. g( t其中定义道路的句子,如下所示,是什么意思啊?
" E% T8 Y# s! |1 {7 [3 b [ set roads patches with& a/ Q. A+ h( m9 G3 H1 Y m
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
e" X# e2 C7 w& j* f0 r/ l" _( f (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
, f4 t3 b! D1 o1 V# F, w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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