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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。
) K" l0 t: [* E- y! p" K( rnetlogo自带的social science--traffic grid这一例子当中,% o0 S. _0 }5 r0 V7 V
globals, j7 t5 _/ R1 R2 g, B9 y2 K, o
[
) ?; Y# v9 o1 _. t) x! v# E grid-x-inc ;; the amount of patches in between two roads in the x direction
7 `' R! V8 J. @' s, s# r7 \& G grid-y-inc ;; the amount of patches in between two roads in the y direction
& g% F, c# F/ o( n& ~ acceleration ;; the constant that controls how much a car speeds up or slows down by if' L I' M% D$ @1 ~ S2 g
;; it is to accelerate or decelerate# c+ x2 b" i" M) h: C- Q
phase ;; keeps track of the phase
. u# N) J# I" M+ U& D num-cars-stopped ;; the number of cars that are stopped during a single pass thru the go procedure0 l% @4 `6 x, J9 t% C2 G3 T% U
current-light ;; the currently selected light
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0 y9 k+ ?5 F& `/ G: ~ t/ `5 U4 V ;; patch agentsets
4 e# \# k& s5 f8 v intersections ;; agentset containing the patches that are intersections, Q$ h, Z: |4 |) b4 {
roads ;; agentset containing the patches that are roads, ]: O; n. j2 {6 @ h2 U
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turtles-own4 U9 Q. \0 Z" q8 z6 ~$ s
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speed ;; the speed of the turtle
3 p& r- C3 o# J$ ?( H4 w# V) X" E% O up-car? ;; true if the turtle moves downwards and false if it moves to the right
|2 [: L' O8 F7 J* M# [ wait-time ;; the amount of time since the last time a turtle has moved
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6 | `7 Q2 Y1 Z3 S) f( v" w$ Ypatches-own
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3 I9 s9 K7 u5 X+ s: O intersection? ;; true if the patch is at the intersection of two roads" K) |6 M1 \8 p: {) ~1 Q
green-light-up? ;; true if the green light is above the intersection. otherwise, false.
! D. G, n" ?6 z$ d. t. A3 K0 ? ;; false for a non-intersection patches.
, K( }4 Y0 W+ E$ F0 o my-row ;; the row of the intersection counting from the upper left corner of the. @ g% Q7 }7 B& d# j
;; world. -1 for non-intersection patches.& o3 A x; ~* F, H |
my-column ;; the column of the intersection counting from the upper left corner of the) _5 C3 ^4 }, T. ]* q
;; world. -1 for non-intersection patches.
# D, X! `; ~0 Z1 m1 M my-phase ;; the phase for the intersection. -1 for non-intersection patches.
: J1 ^% W( H; ?, ~ auto? ;; whether or not this intersection will switch automatically.! q( P6 P8 L9 K& e2 b/ \0 M
;; false for non-intersection patches.
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;;;;;;;;;;;;;;;;;;;;;;
3 N0 o+ Z, o6 `8 N I- q;; Setup Procedures ;;
3 U+ u; [) L2 {/ s;;;;;;;;;;;;;;;;;;;;;;2 s; x; ~9 R9 g5 c6 R: J _9 S
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;; Initialize the display by giving the global and patch variables initial values.
3 q8 |3 N6 j0 y; c;; Create num-cars of turtles if there are enough road patches for one turtle to' N$ w" o W* i6 D
;; be created per road patch. Set up the plots.- O v) E( F$ C3 R* y* |$ O
to setup2 s( |' e/ p0 S# H3 w
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setup-globals. F7 Z5 ^: y: g5 v3 x* G5 x8 `
7 x5 w. e0 d" R0 F5 B6 B2 V ;; First we ask the patches to draw themselves and set up a few variables8 o, y+ K4 ]5 L' h
setup-patches) }% L+ ~ T p6 T3 F
make-current one-of intersections
q; n! k( w5 W b! P label-current: ~3 O) r5 T+ b
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set-default-shape turtles "car"
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if (num-cars > count roads)6 m' Z5 m9 t* l# T/ i
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9 x9 }& R/ k( J6 N3 o1 N user-message (word "There are too many cars for the amount of "
' {/ ~) F% F e: C+ H# V "road. Either increase the amount of roads "( s0 s4 e; `3 V/ ~ H" q
"by increasing the GRID-SIZE-X or "% f! }* X8 \3 V# O7 y4 y% G# t
"GRID-SIZE-Y sliders, or decrease the "/ ~; t9 N, ]$ |1 [9 z0 C z" n
"number of cars by lowering the NUMBER slider.\n"7 K" n2 R* y b6 R0 m
"The setup has stopped.")
7 s- D, H% J% ? stop
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;; Now create the turtles and have each created turtle call the functions setup-cars and set-car-color
( I8 X) Y5 W; k$ A1 x crt num-cars
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8 F' n4 a! V7 u, e5 n setup-cars
1 s$ H* O/ Q2 `2 p: m3 K set-car-color
8 I* P) u5 V! S4 N) O- C6 N record-data
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;; give the turtles an initial speed- Z1 Y+ O( s# l& h/ I
ask turtles [ set-car-speed ]
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8 O3 V S; y( s# O reset-ticks
# l, u( I; Q2 i' yend
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( t: _$ z) [& |. w# a% U;; Initialize the global variables to appropriate values; i8 f; Q& B4 ?0 Z
to setup-globals
' ?) z. b7 N9 }6 P% O set current-light nobody ;; just for now, since there are no lights yet
( m) f; t7 s9 X* t! ] set phase 0
/ U, p2 n& s, B7 S- X# Z set num-cars-stopped 0
- p0 j6 T* N5 V; x5 Y9 n set grid-x-inc world-width / grid-size-x
6 g- t9 ~& H! a" N' j5 Y7 ~4 [ set grid-y-inc world-height / grid-size-y
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: a; @7 M, k7 T/ T- O' D ;; don't make acceleration 0.1 since we could get a rounding error and end up on a patch boundary
\0 \. n! u [1 `& c8 P& j set acceleration 0.099
; x5 k7 |% o4 c) [4 P* tend- @) p5 _3 ~8 n p* K! X
2 F+ j' ]2 K2 N;; Make the patches have appropriate colors, set up the roads and intersections agentsets,
" y1 c g% I$ {4 T- v4 B9 F;; and initialize the traffic lights to one setting
* e; v2 a3 H* K3 O. @ X+ Xto setup-patches
/ O, m& S. i( J9 O* R g2 M" T ;; initialize the patch-owned variables and color the patches to a base-color
( ?) `* v {6 O" K ask patches; x3 \9 w6 Z1 W# r% H
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set intersection? false
' |! y4 ` g& I' J4 B set auto? false
* |* d8 \1 I% r' x7 l set green-light-up? true) ]3 g+ |$ h. H
set my-row -1
! Q5 T3 e; L' k8 W set my-column -1
/ F. T8 H* P4 Q4 W# t0 O8 I set my-phase -1$ m. H/ ~5 x& b' n4 b5 m/ H2 e
set pcolor brown + 3
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" O, `1 h5 l) F0 K+ x% l7 n ;; initialize the global variables that hold patch agentsets
, B" m/ X. t7 w# \4 Q4 S set roads patches with
$ l3 y, ]5 O0 U' `# U [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or8 F! B9 n2 K7 ]( z5 q
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]
/ ]- i+ a# }4 x5 \3 Y set intersections roads with4 R6 t5 }. Z* `
[(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) and
) G6 b! A% `! R/ k) | (floor((pycor + max-pycor) mod grid-y-inc) = 0)]/ a8 Q1 D0 n8 n! @
" n! b7 k# g: j! Y a ask roads [ set pcolor white ]' \* }9 A8 l* c9 C7 _8 r( a
setup-intersections4 r* X) W& |: I+ f4 r" j0 `
end
5 o; T; O* l% ?! b* b其中定义道路的句子,如下所示,是什么意思啊?
) B4 U. }; H1 {( w set roads patches with
4 ^0 C( R1 @! p4 T8 `( u& X* d1 [! y [(floor((pxcor + max-pxcor - floor(grid-x-inc - 1)) mod grid-x-inc) = 0) or" R7 N6 P3 b* u& b$ g
(floor((pycor + max-pycor) mod grid-y-inc) = 0)]+ ]2 z( j7 `* Y( @
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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