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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。; R/ D+ C6 [7 s
netlogo自带的social science--traffic grid这一例子当中,8 t3 j) F/ J8 d) v2 y, Y) L; _
globals2 _3 C. R0 v; d( ?% T
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grid-x-inc ;; the amount of patches in between two roads in the x direction
, q0 C" t5 E2 S3 x5 v' `# l6 L! `$ h1 C grid-y-inc ;; the amount of patches in between two roads in the y direction7 U, R% Y) m7 `$ D9 ]
acceleration ;; the constant that controls how much a car speeds up or slows down by if
, p: ^+ ^" [4 s2 h ;; it is to accelerate or decelerate/ K# j" }' S% `0 P& f( t
phase ;; keeps track of the phase
& }; s1 M: \# }4 m+ R num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure+ h' x; a! _& b
current-light ;; the currently selected light
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;; patch agentsets
7 e) d) B3 h. a9 p intersections ;; agentset containing the patches that are intersections
# B: N' X2 Y0 a, r roads ;; agentset containing the patches that are roads7 Q! a) e* d5 J* A
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turtles-own
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5 ], y5 r6 d$ y6 j4 R speed ;; the speed of the turtle9 v2 K( ~) j. a. l0 P. Z2 d$ k# b
up-car? ;; true if the turtle moves downwards and false if it moves to the right, O4 g+ Q6 M0 e. g
wait-time ;; the amount of time since the last time a turtle has moved
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patches-own* g- u( n5 n" ~7 E1 _0 P$ E
[
0 x" @) s. R0 c3 V4 a0 B- ~& r+ s intersection? ;; true if the patch is at the intersection of two roads
( g b1 ]6 g# r7 \! T8 k; T9 t green-light-up? ;; true if the green light is above the intersection. otherwise, false.& t* t, T2 a, T8 {0 Q' |; ^6 D5 b
;; false for a non-intersection patches.# @$ G& z( r; S# Q, d# l2 m
my-row ;; the row of the intersection counting from the upper left corner of the
2 V4 M% w- H& z' f0 S2 G ;; world. -1 for non-intersection patches.
! |; n. v1 n! Y5 r) {) A+ p my-column ;; the column of the intersection counting from the upper left corner of the+ X) m& Z% ~& X) q! y3 V
;; world. -1 for non-intersection patches.5 p1 P, g7 y q+ @
my-phase ;; the phase for the intersection. -1 for non-intersection patches.. P, r" r/ v, _$ F$ J, f# ?& g
auto? ;; whether or not this intersection will switch automatically.3 K* t% c, ^# M
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;! F0 A/ b$ ]/ s( q" w8 e0 V
;; Setup Procedures ;;6 q! ^0 |" v: l; q- d) v# Y7 Y
;;;;;;;;;;;;;;;;;;;;;;9 ]7 |8 Q, Z: Z( B0 y/ ?, D
: [. t' s: ?) k' @" J;; Initialize the display by giving the global and patch variables initial values.+ ]$ d; z; ?# X5 J/ i( r; V
;; Create num-cars of turtles if there are enough road patches for one turtle to
9 u7 d/ B% `$ d6 w;; be created per road patch. Set up the plots.! g3 M! c2 \! x' q7 J1 U( K
to setup5 G0 i" f* e/ Y# U, i; t- u6 e
ca
: g9 G( T; x5 [ c setup-globals
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$ }( E. A) J! \# ^5 s9 i* } ;; First we ask the patches to draw themselves and set up a few variables7 N `: a' `* H4 J' Q! ?
setup-patches
9 D; L3 t4 j+ l' C8 P make-current one-of intersections
! C9 Y- U' T7 q( b" M2 b label-current: g0 [8 b5 Z( v! v) ~
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set-default-shape turtles "car"/ p# j% w) ^- `4 W3 Q7 e% M
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if (num-cars > count roads)
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; H- H4 D. S0 d" I. S( }' W user-message (word "There are too many cars for the amount of "/ v8 }" A; e H6 F, i0 l
"road. Either increase the amount of roads "+ U8 B6 T4 e2 m$ _, ?+ ^
"by increasing the GRID-SIZE-X or "
1 I, P6 N, \. Y2 R, ? "GRID-SIZE-Y sliders, or decrease the "9 @7 d ^* b8 I$ a3 `. k5 p( \
"number of cars by lowering the NUMBER slider.\n"
* E8 Z7 b% k1 N. ^# [( k "The setup has stopped.")
1 f9 m7 r: N |1 F$ Q3 }0 w stop
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4 c6 `+ G1 E9 c8 q2 D9 y6 t ;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color& h# Q' M3 S) c) n: }
crt num-cars$ }7 R) U( Q) ~* t+ ]) Y. k
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setup-cars% m# l3 Z( |+ m/ ~/ ?' i
set-car-color* d1 b* S6 {2 m4 D+ D U
record-data
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;; give the turtles an initial speed" ~$ M/ a- p2 c- {3 ^
ask turtles [ set-car-speed ]
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) D0 ?5 t9 j" x reset-ticks
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G* C0 F6 P# q9 Q" |;; Initialize the global variables to appropriate values- ^6 k9 {; U7 `' y7 y/ o+ W
to setup-globals
) s. v1 e+ |5 e, b3 O set current-light nobody ;; just for now, since there are no lights yet
- p: r8 {1 c1 N+ n& r set phase 0
0 i( I5 ?. @, D4 w3 W: T set num-cars-stopped 03 k; H- ~+ b" ~7 O, }2 i
set grid-x-inc world-width / grid-size-x# E# ~ S9 L. o6 W$ R
set grid-y-inc world-height / grid-size-y
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) t/ G$ o3 R f! w9 O ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
+ |2 ?1 s' j3 l' F# d set acceleration 0.099" X1 a/ t! b. ~$ \
end
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1 X5 R: y" r" U/ v& O# m9 N( S9 z2 K;; Make the patches have appropriate colors, set up the roads and intersections agentsets, E) V+ x8 z3 J! W# C5 \( O9 T
;; and initialize the traffic lights to one setting+ B# {; x: c3 \
to setup-patches
8 N: z5 @; B) R' }% | ;; initialize the patch-owned variables and color the patches to a base-color
2 e( j) |# T! H9 n& A* ^1 G* s ask patches0 V$ v `8 j S* g& E0 d/ |) _
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) f0 ?! i9 H: z" e0 u3 p set intersection? false
2 A% r# M( C9 D8 L2 Z, d' k% n set auto? false
6 T5 z- |9 A) z/ y1 w+ u9 F set green-light-up? true
- o' A- B+ _% t8 z set my-row -1
. ]2 k" d; o- w3 ?$ \$ }( ^ set my-column -1* f0 B! r+ p- I# J! o9 b8 d
set my-phase -1
# v* x, |- W$ `4 N* m set pcolor brown + 33 r, u$ o4 f( Y$ z6 F
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) T! @- x. m- `( L5 L& m3 d ;; initialize the global variables that hold patch agentsets5 P2 \0 h/ @' b7 L5 V
set roads patches with8 N d! r/ v& V
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or
; H7 \; H7 p S/ y. k7 k (floor((pycor + max-pycor) mod grid-y-inc) = 0)]
, l4 ]; Y d2 Q9 N/ i set intersections roads with
) j+ G1 j, @# h8 t c [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and J8 h# D" A8 d g# d
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]2 u+ {9 Z, O8 ~- P: O( Z! e
3 X: t/ L8 R/ v( ^# ?9 t; } ask roads [ set pcolor white ]
# k- O5 A3 e0 y4 i# F% _) |+ m3 h setup-intersections X0 Y( z- f4 l$ \8 Q
end
, A3 ?2 f) @1 j [6 {' I其中定义道路的句子,如下所示,是什么意思啊? T. k( e4 U% L, {, |; e( [( a, ^
set roads patches with
' D! L, F% C6 u- h [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or1 [0 ]4 G5 t1 C* }7 ~$ P0 B
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]" g; u1 E7 \ l$ H v Q) |
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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