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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。
$ e: D( ?% R9 _# e# Tnetlogo自带的social science--traffic grid这一例子当中,
1 l3 j: R/ h% Q& \, C" Xglobals! \( m9 E% ?: J( ^7 V
[
6 q# j8 ?( K8 \ grid-x-inc ;; the amount of patches in between two roads in the x direction/ f' {2 E3 W* |( ]/ O: t0 h
grid-y-inc ;; the amount of patches in between two roads in the y direction5 M9 d6 y4 [0 S5 r F
acceleration ;; the constant that controls how much a car speeds up or slows down by if8 k" U( a+ T3 g" L8 s
;; it is to accelerate or decelerate
. E1 d9 G" O2 H. i phase ;; keeps track of the phase
/ P+ A' }: e7 Y6 ^ num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure5 k+ h9 K. f4 z5 i9 Q @
current-light ;; the currently selected light/ |3 x, [6 \, }. F$ X# s
- |% A5 `/ b" g/ z. }8 l2 u ;; patch agentsets
9 {# O2 `$ O( [5 v intersections ;; agentset containing the patches that are intersections
! P, D& t+ c/ @7 N- \ roads ;; agentset containing the patches that are roads. }% t- c7 Y, o/ a: A# @6 A
]3 E0 f) \2 T7 c7 L" ]
: d% q4 p; y8 p eturtles-own
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$ c5 @, Q( V& @; l2 Z: l5 I speed ;; the speed of the turtle
1 e/ }7 o5 A r% L/ Z up-car? ;; true if the turtle moves downwards and false if it moves to the right
/ u. ^- c* f- j( E/ ?8 u' o1 G wait-time ;; the amount of time since the last time a turtle has moved( t' Y( o( P! x
]1 J+ o. r$ Q' l' L* Q& k+ l n# P, X
- c" w/ z, \0 e4 B* ~patches-own
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intersection? ;; true if the patch is at the intersection of two roads9 S. J2 K& K7 R- X5 p) g+ R
green-light-up? ;; true if the green light is above the intersection. otherwise, false." ]5 J" A# x/ p2 c3 o
;; false for a non-intersection patches.. P6 v3 l6 G8 Z- m! s' @
my-row ;; the row of the intersection counting from the upper left corner of the
2 E: o2 x' `5 G' O ;; world. -1 for non-intersection patches.
; W6 X3 `9 @) n' u" |' V my-column ;; the column of the intersection counting from the upper left corner of the
# z5 T, r M% I8 ?/ i1 ]& w ;; world. -1 for non-intersection patches.
( q! F6 ~$ y8 w2 r) W my-phase ;; the phase for the intersection. -1 for non-intersection patches.6 O3 t, l. i- X! i; u5 S" U
auto? ;; whether or not this intersection will switch automatically.
3 ?' Q5 q! y& u0 X0 K | ;; false for non-intersection patches.
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b0 L$ B9 ]" \6 E
8 b# l, }3 f2 y, i* P( r# k$ ]2 x% T;;;;;;;;;;;;;;;;;;;;;;5 Z% c# E/ G$ ]; v" L( y
;; Setup Procedures ;;5 m+ ^, j# v( N0 D1 T! F5 W
;;;;;;;;;;;;;;;;;;;;;;2 r% i6 `! P2 y% D# O p
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;; Initialize the display by giving the global and patch variables initial values.5 B; r+ _ V& o3 R
;; Create num-cars of turtles if there are enough road patches for one turtle to
. M' B6 K8 v0 j;; be created per road patch. Set up the plots.4 Z2 A9 X4 z3 H0 h3 X9 E
to setup& P" t2 q5 o* Z [) | j$ c
ca* ]5 @- @/ c! R0 E; P& p
setup-globals
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;; First we ask the patches to draw themselves and set up a few variables
! U. Q/ t0 p4 @1 C% M! v+ P setup-patches$ F1 v$ m: i7 \0 K
make-current one-of intersections
" n- c6 {% a$ {, O2 f2 ^: b: [ label-current, N9 @$ T/ U6 }4 j
) X8 T8 V/ b3 t& T# h6 ? set-default-shape turtles "car"6 k$ z( ]7 q$ T
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if (num-cars > count roads)! p- o. k& Z" @* k
[
r. X& J F( }. I* F1 L$ p& b4 N user-message (word "There are too many cars for the amount of "' ?+ H; O* o$ S3 w' W5 j6 I
"road. Either increase the amount of roads "
% f1 r2 _3 p1 w7 A5 T "by increasing the GRID-SIZE-X or "4 S" s9 ?) z j) i2 d/ G2 @( f! @
"GRID-SIZE-Y sliders, or decrease the "6 [% j2 e# I" x! T8 K2 h o1 R
"number of cars by lowering the NUMBER slider.\n"
( E% H. q. ?/ u- E; \5 D8 J "The setup has stopped.") F( N+ A8 [8 F3 V6 `; d7 h8 O- b
stop2 Q3 T. C B7 {, a8 i5 p( T# A5 q
]% `. u* o. M) b
$ U. T& a3 {- q- }# y! P" ]4 I ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color2 K- z7 L. u2 k" x, W- w( }' P8 X
crt num-cars- t! j" } o: b: b( R: b
[
1 A; u) f v# m setup-cars
: L2 ^! V# F/ o+ k2 \ set-car-color
4 o. V2 Q) a9 ^* n5 x record-data
2 K2 `$ y# Z: q2 D! ]2 y ]
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( i( Y& e% T4 u; u ;; give the turtles an initial speed7 a& |6 @# {$ m$ U8 h9 J7 o8 Y; z+ e* x
ask turtles [ set-car-speed ]
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reset-ticks
/ g. n1 g- U: D) O, k/ eend
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;; Initialize the global variables to appropriate values) w; N* I8 i) ~9 L2 p8 B: r" r3 o
to setup-globals+ ~1 D% n6 b% W* d9 \/ E& |
set current-light nobody ;; just for now, since there are no lights yet
( z3 N3 F4 e) d. z3 j set phase 0
/ y. R8 L1 C0 X& N2 ?! P# D0 N5 f set num-cars-stopped 0
$ R+ d/ C: n9 O8 z set grid-x-inc world-width / grid-size-x
7 h0 }5 r) z1 |$ y8 Q' j set grid-y-inc world-height / grid-size-y+ |2 V; {& G; N/ ]7 M
W; Q2 I |6 A
;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary6 e8 t4 P: L! g* c$ ]' N7 P7 y
set acceleration 0.099
# \* {8 {9 _5 E/ jend X) G G0 _) j6 \
# j, D4 I* n6 K- B7 x. m;; Make the patches have appropriate colors, set up the roads and intersections agentsets,# @* l. @8 Z0 X1 ~8 g
;; and initialize the traffic lights to one setting$ z" e( a- J' [! Q5 U* Y" O6 z5 y
to setup-patches! z+ {; x. P- q. N
;; initialize the patch-owned variables and color the patches to a base-color
: \# s% D2 D6 r+ t ask patches
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set intersection? false
, ^6 Q l% g$ L& z* ?6 A set auto? false
7 }8 F8 G* o# F6 v; F- G3 h s set green-light-up? true
6 x( N' E [& j: H7 |! c set my-row -1
; @( @1 Q# F' N set my-column -12 v* g3 X& \2 ~# E
set my-phase -1
7 d" j @; l2 t* \8 @7 P set pcolor brown + 3
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5 |$ \: s* J4 K ;; initialize the global variables that hold patch agentsets
' e7 n! v1 F4 ^" z" P9 V set roads patches with7 n8 h0 t, u" }( A
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or; d7 g( R# R E
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]% |4 h/ C1 [6 t1 ^, r' h( I
set intersections roads with
: m& E& H1 K& \/ @% V# a: \ [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and) i1 K, D0 L( q+ d, f1 W
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]0 V/ T; F- _+ |; j
3 J( ^. S" J" y ask roads [ set pcolor white ]
/ g% I- X$ j( S2 i" w setup-intersections6 ~; |+ w( `' _! `0 L
end
$ E( N* g3 q1 Y. M! h" Q* p* G) ]7 p其中定义道路的句子,如下所示,是什么意思啊?
& u" _" ]9 ]2 c6 h2 i- d4 n set roads patches with
M# z0 F f6 [+ Z9 N3 v [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
& T$ e% J) f1 G (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
* B& `# v7 s) }5 f6 `* N, f3 P9 L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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